Replaceable You: Adventures in Human Anatomy

by Mary Roach

From the New York Times best-selling author of Stiff and Fuzz, a rollicking exploration of the quest to re-create the impossible complexities of human anatomy.

The body is the most complex machine in the world, and the only one for which you cannot get a replacement part from the manufacturer. For centuries, medicine has reached for what’s available—sculpting noses from brass, borrowing skin from frogs and hearts from pigs, crafting eye parts from jet canopies and breasts from petroleum by-products. Today we’re attempting to grow body parts from scratch using stem cells and 3D printers. How are we doing? Are we there yet?

In Replaceable You, Mary Roach explores the remarkable advances and difficult questions prompted by the human body’s failings. When and how does a person decide they’d be better off with a prosthetic than their existing limb? Can a donated heart be made to beat forever? Can an intestine provide a workable substitute for a vagina?

Roach dives in with her characteristic verve and infectious wit. Her travels take her to the OR at a legendary burn unit in Boston, a “superclean” xeno-pigsty in China, and a stem cell “hair nursery” in the San Diego tech hub. She talks with researchers and surgeons, amputees and ostomates, printers of kidneys and designers of wearable organs. She spends time in a working iron lung from the 1950s, stays up all night with recovery techs as they disassemble and reassemble a tissue donor, and travels across Mongolia with the cataract surgeons of Orbis International.

Irrepressible and accessible, Replaceable You immerses readers in the wondrous, improbable, and surreal quest to build a new you.

Genres: Nonfiction, Science, Audiobook, Medical, Humor, Medicine, Health

288 pages, Hardcover

First published September 16, 2025

About the author

Mary Roach is a science author who specializes in the bizarre and offbeat; with a body of work ranging from deep-dives on the history of human cadavers to the science of the human anatomy during warfare.

Mary Roach is the author of the New York Times bestsellers STIFF: The Curious Lives of Human Cadavers; GULP: Adventures on the Alimentary Canal, PACKING FOR MARS: The Curious Science of Life in the Void; BONK: The Curious Coupling of Science and Sex; and GRUNT: The Curious Science of Humans at War.

Mary has written for National Geographic, Wired, Discover, New Scientist, the Journal of Clinical Anatomy, and Outside, among others. She serves as a member of the Mars Institute's Advisory Board and the Usage Panel of American Heritage Dictionary. Her 2009 TED talk made the organization's 2011 Twenty Most-Watched To Date list. She was the guest editor of the 2011 Best American Science and Nature Writing, a finalist for the 2014 Royal Society Winton Prize, and a winner of the American Engineering Societies' Engineering Journalism Award, in a category for which, let's be honest, she was the sole entrant.

Reviews

[Olive Fellows (abookolive) · Rating 3.75 out of 5]

The human body is an incredibly complex machine, and efforts to emulate it enough to replace parts of it are at the very least difficult, if not impossible. This is classic Mary Roach with a bit more complicated science.


Click here to hear more of my thoughts on this book over on my Booktube channel, abookolive!

[Wanda Pedersen · Rating 4 out of 5]

In my opinion, this is a slightly less entertaining book by Mary Roach. She still glories in the oddities of her chosen subject, but there seem to be fewer occasions for it. I was pleased to learn that Roach has a friend, Steph, who seems to be willing to drop everything and fly to Tbilisi to attempt to interview a surgeon who has used a cancer patient's finger to replace his penis. Steph makes smart-alec comments just like Mary. Everyone needs a friend like this.

Roach is so much more adventurous than I. I find myself wishing that I had her chutzpah. She interviews surgeons, witnesses their procedures, learns about entubation with an anesthesiologist, gets in an iron lung to experience what a polio victim did, treks to Mongolia with an ophthalmic team, and visits a practitioner in Mexico who does butt lifts, among other activities.

Having finished the book, I must confess that I am confirmed in my aversion to ever undergoing another surgery. I am profoundly thankful for the procedures I have benefited from, but I will have to do some serious forgetting before willingly having a joint replacement, despite my gimpy knee. If I never go under anesthetic again, it will be too soon. I discovered that I am more squeamish than I believed about surgery. I've undergone cataract surgery and bless it, but reading about it was difficult. The description of cosmetic surgery, including breast implants, was distressing for two reasons: the blatant disregard for women's health and comfort; and the also blatant assumptions of the male surgeons deciding what is attractive and/or necessary for their female patients. Roach spent time with a surgeon who performs transgender surgeries and who seemed to belong to a minority of doctors who actually asked the client what they wanted and then believed them. For example, when a trans woman tells you that she won't be needing a functional vagina, there's no reason to spend time and resources to create one.

The footnotes along the way are worth the price of admission. Roach is a magpie with an eye for a shiny fact and she remembers very obscure details. I can't imagine how she spends her spare time, but I like to imagine that she reads esoteric journals and rare books. I also am heartened by the number of researchers and physicians who are willing to take time out of their schedules to answer questions, discuss theories, lead tours, and speculate about the future. Their bravery to share their expertise is inspiring.

I maintain my stance that I would love to have coffee with Ms. Roach. I know this is an impossible wish, but boy would it be fun.

[Will Byrnes · Rating 5 out of 5]

It’s another photograph of the penis [transplanted from the owner's middle finger], now with a rustic ceramic pitcher hanging off of it. Exactly as you or I could put a hand out, palm up, and hang a pitcher off our middle finger. The pitcher is hand-painted, white with a red and green floral pattern. I’m picturing the man and his partner again, this time having lunch in the kitchen. A little iced tea, my love?

--------------------------------------

Eventually the day arrives when no further breach is possible. Mr. Baron, wrote his doctor, Richard Martland, “was now informed, the only chance for saving his life was by making an artificial anus . . . the inconveniences resulting from such operation, were candidly pointed out to him.” Mrs. White, on the occasion of her twelfth day without a bowel movement, is presented with the same proposition. Both patients consented. Or rather, as Pring put it, “did not violently object.” And so it went. “An opening was now made . . . and instantly a large quantity of liquid feces and wind escaped,” Martland wrote. Both doctors were impressed by the force with which the matter was expelled, with Pring taking additional note of the “considerable distance” traveled. - There was no mention of a fan in the vicinity.

This book certainly lends new meaning to the expression "an heir and a spare."

I imagine many of us, certainly folks of my demographic, have had the experience of having parts replaced, probably because of need, but for some because of choice. I know I would happily have my begrudging spine replaced if I had the chance. And there are certainly a few improvements I could use that would be competing for second place on that list. Thus, my interest in Mary Roach’s latest, Replaceable You. (My ex can attest to the truth of the title’s applicability to the entire me.) Of course, I would read anything Mary Roach has written. She is one of my all-time favorite authors. And just in case her work is new to you, she combines a hard-reporting look at a particular scientific realm with a sense of humor that will leave you gasping for breath. Complete swallowing any ingested liquids before reading her work, as they may come blasting out your nose and mouth before you can get a grip. You have been warned.


Mary Roach - image from Harvard Bookstore - shot by Jen Siska

Roach has made a career of writing about the human body, from conception (Boink) to grave (Stiff), and beyond (Spook), with travels through the alimentary canal (Gulp), the body’s reaction to space flight (Packing for Mars), to war (Grunt) and even to strangeness having to do with our interactions with animals (Fuzz). This time around, she covers a range of body parts subject to replacing. She sniffs out the history of nose jobs back to the 1500s, and lets us in on why they were in such high demand back then. She brings home the bacon by filling us in on the status of pig research (on, not by) for the purpose of developing organs that can be transplanted into humans, a subject close to my heart.

A formal “miniature swine development” project got underway in 1949, a collaboration between two Minnesota powerhouses, the Mayo Foundation (research arm of the Mayo Clinic) and the Hormel Institute (research arm of pork).

There are sections on the replacement, or enhancement, of sexual organs. One of the opening quotes of this review notes a particular form of actual, not kidding, replacement for a male member. Female anatomy comes in for a bit of consideration as well.

Dow Corning…made the first silicone breast implant, circa 1961, this one at the urging of Texas plastic surgeon Thomas Cronin. Cronin had been “inspired by the look and feel of a bag of blood.” It is hard for me not to picture the scene: Cronin standing around the OR, idly gazing at a bag hanging on a transfusion pole and turning to a colleague: Hey. Does that remind you of something? Cronin contacted Dow, and his resident, Frank Gerow, implanted some prototypes into dogs. The team were “excited” by the outcome—and again, stop me from picturing this.

Continuing downstairs…

Who looks at the human digestive tract and thinks, Moist, tubular, stretchy . . . Might that make a reasonable vagina?

Some, apparently. The derriere comes in for a long look as well. Part of this is a consideration of the changing fashions in tush shape, stretching from sane to anime.

I have made it (well in) to septuagenarian with what is probably an unremarkable range of replacement parts. My right arm was the recipient of two metal plates and a bone graft from my hip after a rather nasty industrial accident in 1970. The plates were removed once they had done their job of helping my bones knit, a few years later. The bone graft helped heal another fracture, and was eventually absorbed back into my skeleton.

Roach tells of prosthetic limbs, and the surprising news that some people prefer them to the original. In fact, the initial inspiration for this book came from a reader who had suggested that Mary take on the exciting world of football referees. Understandably, that failed to score, but it turned out that the woman, who has spina bifida, had a problem with her foot. It had, as a result of her other difficulties, become less than useless. She wanted it removed so she could get a prosthetic, but few surgeons would consider electively removing it. Mary joined her at the Amputation Coalition National Conference, and the game was…um…afoot.

It will come as no shock that using one’s own body bits as a source of transplantation offers the huge advantage of sparing you the need for a lifetime of immunosuppressive drugs. The body’s Studio 54 security guard can take a quick look and wave the new part in as the right sort. It worked for me a second time.

Other recent personal additions were the product of open-heart surgery, three stents and an aortic valve replacement. The stents were made up of material extracted from my right leg, and the valve was contributed by a member of our porcine community. I have yet to experience any desire to go digging for truffles in nearby woodlands.

Roach takes joy in comparing the techniques and tools of hip replacement surgery to woodworking, noting that while patients could actually be conscious during the surgery, the clanging, sawing machinery noise would be so disturbing that it is deemed preferable for patients to remain unconscious for the duration. She says that “Hip replacement has the visual drama of a visit to a Chevron station.”

Sadly, I was born with a mouthful of (well, maybe not born with, which would be weird, but ultimately host to a couple of sets, baby and adult) soft teeth (my dentist’s words). This led, over time, to a need for fillings, caps, bridges and dentures.
.
If you count up all the teeth that are removed and replaced with implants or dentures, I bet they would lead the pack in sheer numbers of replacement bits. Mary leads us on a walk through dentures in history, the up and down sides, as well as the benefits of not using them at all. Yes, Geoge Washington makes an appearance. You will find the section on spring-loaded replacements both fascinating and alarming, and concerning as well is the fact that so many people have elected to remove healthy teeth in order to install dentures.

Replacing hair is big business these days. But not just up top. Pubic hair is also replaceable. Not only can the short and crinkly be replaced, with hair from the head, but the opposite can be done as well. Of course this can present some grooming challenges, as pubic and head hair grow differently and behave inconsistently when treated with grooming products. Mary subjected herself to a bit of hair harvesting in her travels.

My donor site is smeared with bacitracin, but no gauze is taped in place, because my hair would get stuck. On the flight home, I will feel the back of my head start to ooze. Do you fly Southwest? Don’t sit in 11B.

She delves into the growth industry of 3D printing of bodily materials. It turns out that it is not so simple as it might seem. Each muscle and organ has particular abilities and behaviors that are very difficult to replicate, involving twisting, contracting, and reacting to incoming messaging from the brain. The Star Trek replicator might do a great job of producing “Earl Grey, hot,” but fabricating people-pieces is proving a much more complex undertaking than sci-fi writers imagined.

Eye lenses are being replaced at increasing rates. There are even many people who, as with tooth replacement noted above, are having their natural lenses replaced in order to improve their vision.

I have worn glasses since I was eight years old, for distance. The only issue I had with them was losing track of them. But in the last few years, it became obvious that there was a buildup of material on the left lens of my eye (not just the product of inattentive eyeglass wiping) that made night driving particularly challenging. Oncoming headlights, even non-bright ones, spread a glare across my field of view that was problematic. I had cataract surgery earlier this year (2025), left eye only. And it worked like a squeegee on a filthy window. The headlights are still miserable, particularly when people insist on using their brights, and when many newer cars use lights that are brighter than the prior generations of illumination, but the improvement in my vision was immediate.

She writes about the processes involved in recovering bio-materials from the recently dead, the potential for banking our own cells as a source for future replacement materials, a machine for offloading heart and respiration work from the body temporarily, and introducing us to the wonderful world of ostomies, noted up top.

Mary may write about science, but she is not, per se, a scientist. Thus, she can offer us an every-person view into the subjects she investigates. She reacts how we might react when faced with the same discoveries. She brings the oh, wow!, the joy-of-discovery moments to life for readers, and thus makes what she has learned stick for us more than it would from any dry textbook. If she leaves you in stitches, that might just be a part of your replacement work. If you burst with laughter, bust a gut, if you crack up or your laughter is side-splitting, that may be why you needed the work in the first place. Of course, if you laugh your head off, there is probably no short-term solution to that. Replaceable You is the real thing, as is Mary Roach. She is one of a kind. Accept no substitute. She is irreplaceable.

Nana takes a seat at Kuzanov’s desk and starts opening files on his computer desktop. After a few false starts, she locates a folder of photographs documenting a finger transplant performed on a cancer patient. Most of the man’s penis had been amputated, leaving him unable to do two of the things most men like to do with their penis: penetrate and pee while standing. The surgery would restore both. - She missed one.

Review posted - 09/19/25

Publication date – 09/16/25

I received an ARE of Replaceable You from W.W. Norton & Company in return for a fair review. Thanks, folks, and thanks to NetGalley for facilitating. And could you check to see if anyone left any spare spines lying around.



This review is cross-posted on my site, Coot’s Reviews. Stop by and say Hi!

=============================EXTRA STUFF

Links to Roach’s personal, Instagram and Twitter pages

Profile - from her site

I grew up in a small house in Etna, New Hampshire. My neighbors taught me how to drive a Skidoo and shoot a rifle, though I never made much use of these skills. I graduated from Wesleyan in 1981 and drove out to San Francisco with some friends. I spent a couple years working as a freelance copy editor before landing a half-time PR job at the SF Zoo. On the days when I wasn't there in my little cubicle in the trailer behind Gorilla World, I freelanced articles for the Sunday magazine of the local newspaper. One by one, my editors would move on to bigger publications and take me along with them. In the late 1990s, magazines began to sputter out and travel budgets evaporated, and so I switched to books.
People call me a science writer, though I don't have a science degree and sometimes have to fake my way through interviews with experts I can't understand.
I have no hobbies. I mostly just work on my books and hang out with my family and friends. I enjoy bird-watching (though the hours don't agree with me), hiking, backpacking, overseas supermarkets, Scrabble, mangoes, and that late-night "Animal Planet" show about horrific animals such as the parasitic worm that attaches itself to fishes' eyeballs but makes up for it by leading the fish around.

Interviews
-----Stuff to Blow Your Mind on iHeart - Replaceable You, with Mary Roach by Robert Lamb – audio (36 minutes) with available transcript
-----Peculiar Book Club - MARY ROACH is Un-Replaceable! - video – 1:10:03 – from 5:00
-----NPR - From heart to skin to hair, 'Replaceable You' dives into the science of transplant with Brandy Shillace
-----Association of Health Care Journalists - Mary Roach calls herself ‘the gateway drug to science’ by Lesley McClurg

Other Mary Roach books we have enjoyed
-----2021 - Fuzz: When Nature Breaks the Law
-----2016 - Grunt: The Curious Science of Humans at War
-----2013 - Gulp
-----2010 - Packing for Mars
-----2006 - Spook Six Feet Over - recently renamed
-----2004 - Stiff

Items of Interest
-----New York Times - 10 Icky Things Mary Roach Has (Unfortunately) Brought to My Attention - by Sadie Stein - from sundry MR writings, in case you have not laughed enough from reading her latest
-----Bauman Medical - What is a Pubic Hair Transplant?
-----Youtube - A particularly disturbing transplantation scene from the 1973 film Oh Lucky Man

Song
-----Beyonce - Irreplaceable

[Melki · Rating 4 out of 5]

Roach turns her always curious eye to replaceable body parts. From prosthetic limbs to 3D printed organs, this engrossing subject matter is made even more fascinating by Mary's enthusiasm and wit. The skin grafting chapter made me a little queasy, so perhaps chose a different book for your lunchtime read.

Many thanks to W.W. Norton and NetGalley for sharing.

[Kasia · Rating 3 out of 5]

I have a strong feeling that this book was more fun to write than it was to read. Cudos to author, the adventures she took must have been amazing to experience but for me as a reader it felt like watching endless pictures from someone elses vacations.

I've read majority of Mary Roaches previous books and always found them very refreshing - author's curiosity is endless if somewhat middle-grade and I've always enjoyed her deep dives into obscure research or shadowy corners of the internet. However, Replacable You is mainly focusing on interviews author had with scientist, doctors and activists and I found them to be pretty weak - the pop science in this book is barely there and instead we are getting a lot of pointless details about what author ate during the discussion, what she saw or how she percived the person she was interviewing. On more than one occasion I found her pretty insensitive/expoitative too - like when she spent the night in an Iron Lung that was belonging to the deceased woman and felt compelled to describe the grief of her spouse. Other than that it was a pretty ok, quick read that briefly touches upon such topics as ostoma bags, amputations, gender changing operations, hair transplants, BBL, xenotrasplantation, cataract operations, skin trasplants and couple more.

A little bit of a let down.

[Left Coast Justin · Rating 3 out of 5]

Like all the Mary Roach books I've read, this one was compulsively readable and completely forgettable. I really enjoyed the first chapter and after that it all sort of blurred together. But I was having fun while I was immersed in it.

[PATCHES · Rating 5 out of 5]

✨ ARC Review! ✨ Special thanks to friends over at W. W. Norton & Company for sending me an early copy of Roach’s “Replaceable You” not only to gush over, but to prepare for my interview tomorrow with Mary Roach herself! (If you’re curious yes of course I’m screaming because of it)…

It’s no surprise that this is incredible. You can tell Roach had a fantastic time researching and writing this book. I learned so much, as I always do. The evolution of body modification is one I knew little to nothing about; from hair transplants, to prosthetic limbs, tissue donations, and cataract surgery, Roach with her classic whit and morbid curiosity (I had to) provides another classic with anecdotal stories and in-the-lab updates that sometimes, in the name of science, she experienced for herself.

This is releasing September 19th. Preorder it today, go support her. This was great.

[Beth Knipper · Rating 2 out of 5]

first time her humor just fell flat for me and felt out of place.

[Rachel · Rating 4 out of 5]

I adore Mary Roach--I will learn whatever she's trying to teach us. This time, it's how doctors and scientists use artificial body parts to replace when their original counterparts malfunction or are irreparably injured. Yes, this is technically a medicine/science book, but, as with all of Roach's work, you could shelve it in the humor section as well. I learned, among other things, that the doctor she was looking to contact in one chapter was the man she lost her virginity to in college and that Mitch McConnell's facial structure may make it harder for him to be intubated.

If you want to learn a new subject but don't want to pick up a dense, textbook-like tome, Mary Roach's books may be for you.

[Grace · Rating 3 out of 5]

Interesting as always, but didn't quite hit the way some of her past books did. I found her irreverent style started to grate a little bit here, and I suspect that is largely because my tastes have evolved since I first started reading her books. Relatively light, and an intriguing subject, but I think I may have slightly gone off pop science NF.

[Amy · Rating 2 out of 5]

Mary R: why aren’t people in China forced to donate their body parts? After all, it is China (literally said this lol)
Answer she got: because of religious practices. It’s up to an individual person to choose to donate their body parts.
Mary R: I still think they should be forced to do so.

Note: Mary Roach lives in USA where one CHOOSES to donate their body and guess what, Mary isn’t donating hers! lol but she likes the idea of it, but hasn’t decided on it. But hey, other countries should definitely force their citizens to do so, just not her :) (this is based on what she said from previous interviews and her last book called stiff)

Also, the whole book reads like a stack of pamphlets. You’re better off just googling random topics and you’ll get better answers without the cringe level jokes :)

Mary R: I’m often asked if I’m a doctor because of how much medical language I know & they’re so surprised to learn that I am not! Also Mary R: I thought an anesthesiologist was like a medical guard :)

[aPriL does feral sometimes · Rating 5 out of 5]

‘Replaceable You: Adventures in Human Anatomy’ by Mary Roach is a delight! If you have read a science book by Roach before and loved it, I can assure you this is another very cool lovable read! She mixes in many deeply researched science subjects, in this case, how scientists are looking for materials the body won’t reject to fix cloudy eye lenses, male-pattern baldness, misbehaving intestines, missing limbs, and many other body-parts issues, never flinching from the sometimes gruesome aspects only medical staff see, with humorous asides which often are completely inappropriate 😂. Some of the work is seriously important to keep people alive, while others might seem to be frivolous in comparison. Nonetheless, serious scientists are working hard on experiments with materials which the body will hopefully accept or on surgical techniques that fix a body problem, whether it is about saving the sight of someone going blind or if it is about women with perfectly good buttocks but they want butts instead that look exactly like Kim Kardashian’s.

I have included the book blurb:


Goodreads Choice AwardNominee for Readers' Favorite Nonfiction (2025)

From the New York Times best-selling author of Stiff and Fuzz, a rollicking exploration of the quest to re-create the impossible complexities of human anatomy.

The body is the most complex machine in the world, and the only one for which you cannot get a replacement part from the manufacturer. For centuries, medicine has reached for what’s available—sculpting noses from brass, borrowing skin from frogs and hearts from pigs, crafting eye parts from jet canopies and breasts from petroleum by-products. Today we’re attempting to grow body parts from scratch using stem cells and 3D printers. How are we doing? Are we there yet?

In Replaceable You, Mary Roach explores the remarkable advances and difficult questions prompted by the human body’s failings. When and how does a person decide they’d be better off with a prosthetic than their existing limb? Can a donated heart be made to beat forever? Can an intestine provide a workable substitute for a vagina?

Roach dives in with her characteristic verve and infectious wit. Her travels take her to the OR at a legendary burn unit in Boston, a “superclean” xeno-pigsty in China, and a stem cell “hair nursery” in the San Diego tech hub. She talks with researchers and surgeons, amputees and ostomates, printers of kidneys and designers of wearable organs. She spends time in a working iron lung from the 1950s, stays up all night with recovery techs as they disassemble and reassemble a tissue donor, and travels across Mongolia with the cataract surgeons of Orbis International.

Irrepressible and accessible, Replaceable You immerses readers in the wondrous, improbable, and surreal quest to build a new you.”

No story Roach tells in the book is dull. All of it is fascinating. Plus she asks the questions all of us would ask if we were as fearless as she, no matter how intrusive or shameless.

The chapters are:

-To Build a Nose: The Dawn of Replacement Body Parts
-Gimme Some Skin: Replacing the Human Exterior
-Mixed Meats: Humans with Pig Organs, and Pigs with Human Organs
-Heart in a Box: Creating Ultra-Long Life Organs
-The Vagina Dialogue: Repurposing Your Parts
-Giving the Finger: Some Transplants are Tougher Than Others
-The Cut-Off Point: Longing for a Prosthetic Leg
-Joint Ventures: Woodworking without Wood
-Intubation for Dummies: The Brief Terrors of Mechanical Breathing
-Heavy Breathing: Inside the Iron Lung
-The Mongolian Eyeball: With Cataract Surgery, Sometimes Simpler is Better
-The Last Six Inches: Battling the Stigma of Ostomy
-Out of Ink: How to Print a Human
-Shaft: Hair Transplants Through the Ages
-Splitting Hairs: Grow Yourself from Scratch!
-The Ass Men: Chasing Perfection with Math and Fat
-Some of the Parts: A Day in the Life of a Tissue Donor

The above titles only describe the main subject of the chapter, but there are additional related informational bits and pieces Roach throws in. The history behind each modern development is just as fascinating as what is being done today, sometimes even more so.

Sadly, there is an Epilogue chapter which describes the collapse of the non-profit and for-profit providers of medical care and of the institutions of medical research she profiled in the book because of the Trump Administration’s stoppage of ongoing financial support and grants. Some had contracts with the Federal Government, and they are wondering about what legal options they have to enforce their contracts.

There are Acknowledgment and Sources sections.

[Sarah Jensen · Rating 5 out of 5]

Replaceable You: Adventures in Human Anatomy – A Masterclass in Scientific Curiosity with Heart
Rating: 4.8/5

Mary Roach’s Replaceable You is a triumph of science writing that marries razor-sharp inquiry with disarming humor, taking readers on a wild ride through the frontiers of human body engineering. As someone who devours popular science but often struggles with clinical detachment, I found Roach’s blend of empathy and wit utterly captivating—like having a brilliant, slightly mischievous tour guide through the uncanny valley of medical innovation.

Why This Book Shines
Roach’s genius lies in humanizing the surreal. Whether observing cataract surgeries in Mongolia or chatting with ostomates about designer stomas, she elevates technical marvels into deeply personal stories. The chapter on prosthetic limbs—exploring the emotional calculus of choosing augmentation over biological limbs—left me awestruck by both the technology and the resilience of those who use it. Her visits to stem cell labs and xenotransplantation facilities (like China’s “superclean pigsty”) balance wonder with ethical nuance, never reducing subjects to mere curiosities.

Emotional Resonance & Intellectual Thrills
This book made me laugh out loud (her description of 1950s iron lung users hosting dinner parties is classic Roach) and pause in reverence (the tissue donor dissection scene is hauntingly beautiful). I appreciated how she normalizes “taboo” topics—vaginal reconstruction using intestinal tissue, for instance—with matter-of-fact compassion. The section on 3D-printed organs sparked equal parts hope and existential dread: Are we solving scarcity or playing God? Roach doesn’t preach answers but lets the questions linger provocatively.

Constructive Criticism
While Roach’s irreverence is usually a strength, a few jokey asides during sensitive topics (e.g., donor families’ grief) risked tonal whiplash. The book also leans heavily on U.S. and East Asian case studies; voices from African or South American innovators could have enriched its global perspective. A deeper dive into cost/access barriers of these technologies would’ve added socioeconomic depth.

Final Verdict
Replaceable You is Roach at her best—curious, compassionate, and endlessly entertaining. It’s not just about the science of replacement parts but what it means to be irreplaceably human in a world of medical miracles.

Thank you to Edelweiss and W. W. Norton for the gifted copy. This book left me marveling at my own body’s fragility and the audacity of those striving to rebuild it.

Pair with: A strong stomach and a sense of humor—you’ll need both when reading about pig-heart transplants over lunch.

For fans of: Stiff (Roach’s own classic), The Emperor of All Maladies by Siddhartha Mukherjee, and Being Mortal by Atul Gawande.

[Emily Poche · Rating 4 out of 5]

Thank you to W. W. Norton & Company for providing this ARC for review consideration via NetGalley. All opinions are my own.

Replaceable You is a nonfiction pop-science exploration into the science and culture of body part replacement. From iron lungs to butt implants, Mary Roach lifts the curtain on the most mundane and most scientifically advanced replacement parts medicine has to offer.

Roach approaches the topic or new (or new-to-you) body parts with her signature candor and curiosity. She interjects a layman’s level of grounding to the topics she explores while still being careful to explain the science and research accurately. This is Roach in classic form. If you’ve ever picked up one of her titles before, you’ll find yourself pleasantly fulfilled. The tone is familiar, but she chooses topics that are snappy, interesting, and easily conveyed. In the grand scheme of her works it isn’t my favorite, (the honor, or course, goes to Stiff), but it’s a very good option.

My favorite chapter of this book concerns the one where she witnesses an organ donation in progress. Her account was humanizing across the board; a company concerned with accuracy and dignity, the donor, the slightly concerned family, and the technicians who are both respectful and light through the process. Organ donation can be mired in controversy, and often, as the author states, only gets press for horror stories. It was refreshing to hear about a mundane occasion in which things go right.

One of my favorite things that Roach does in her structuring of the book is find ways to build connections from one topic to another. Rather than chapters standing alone, each a miniature story, they are often linked by through ideas or they build upon each other. I was particularly pleased by the way the chapter about colons being repurposed into neophalluses flower into the trip to see the finger-penis. What a delightful way to show how these medical advances (or experiments) seem to spiral out from one another into new areas of study.

I would say that what I didn’t always find to be on par with the rest of the book is that at times there’s an off putting air from the author. While this is less evident in chapters where she interacts with physicians and researchers, there’s a slightly paternalistic or at least ignorant element to some of her questions or observations when confronted with device users. While she’s never overt and may just be admitting misconceptions through honest recollection, at times it feels uncomfortable to read her bumble through interactions with amputees and bereaved caregivers.

If you like pop science books and are interested in beginning to explore the science of medical devices and implants, this is a great primer on the topic. Like wakes, for Mary Roach fans, you’ll also find her writing to be in fine form. 4.25/5!

[Keri Stone]

I rating for this since I did not finish. It’s an interesting topic, how science has evolved to try to replace body parts as needed. This seems like a more recent development, but actually has been occurring for a long time. Some seem obvious, like false teeth, wooden legs as early prosthetics, and even replacement noses and ears. Whether taking our own body parts to use in other places (skin grafts), using parts from other humans, or animal parts… many things have been tried.

This book is a book club selection, and I was interested to read it. I enjoyed learning some new information, but ultimately it just didn’t keep my interest. That’s probably as much about me and my interests as it is about the book. I’ll be curious to hear what my book club members thought - and I’m thankful for my group that encourages attendance whether you’ve read the book or not - no shame.

[Komal · Rating 4 out of 5]

This was so fun to read. I took my time with this one.
Mary has been successful in communicating the intricacies of the biomedical processes without sounding a bore.
I,truly, hope medical sciences advance further in the coming years and these scientists are successful in their endeavours.

The best thing about this book is how cleverly the author connected the previous chapter to the next one. It made the reading experience flawless and the information is easily retainable.

[Camelia Rose · Rating 5 out of 5]

Replaceable You is the latest nonfiction by Mary Roach. Organized by body parts, it is a mix of the latest medical process and history. I enjoyed this book very much. Mary Roach writes such funny non-fiction books. If you wonder how your body parts, as big as legs and hearts, as small as hair or tears, even just a group of cells, can be replaced to save your life or improve your health, this is the book for you. I am in awe of the latest medical advancement in genetics and surgery, but disappointed that viable organ printing still has a very long way to go.

[Sonja Arlow · Rating 3 out of 5]

3.5 stars

This book takes you on a journey across a wide spectrum of body‐part replacements. From traditional prosthetics to modern breakthroughs like 3D-printed organs and lab-grown tissues

As is Roach’s signature style, she mixes science reporting, personal stories, travel, and reflections in a way that makes complex concepts readable.

Roach also relies heavily on copious footnotes to add additional quirky facts which does not always make for the smoothest reading experience. My reading tastes these days lean more towards the writings of, for example Sam Kean where offbeat stories are incorporated into the actual narrative.

This is a nice little book, and I won’t discourage anyone from reading it but it didn’t wow me as much as her earlier works like Stiff: The Curious Lives of Human Cadaversor Gulp: Adventures on the Alimentary Canal.

[Ayo · Rating 5 out of 5]

Exquisite. Morbidly beautiful. Brilliant. Super Cool.

I still can’t believe Mary is not a medical doctor.

This quote towards the end sums up the thesis and resolve of this book. However the journey and Mary’s diary through it was worth reading:

“Even the simplest parts of the human body defies efforts to recreate it. Which caused me to ponder what the simplest parts actually was.”

[Renee Roberts · Rating 4 out of 5]

Remember The Six Million Dollar Man? The tagline was "We can REBUILD him!" Apparently, rebuilding our multiple parts after the thousands of ways our bodies fail or are damaged has been a quest for hundreds of years.

Mary Roach presents her encyclopedic foray into the world of replacing human tissue and organs, its history and advances with her characteristic humor and curiosity. Bravely travelling the world to witness research and procedures, she even volunteers herself for some experimentation. I've been a fan of Mary Roach for years. She always provides a level of science and variety to educate and inform me, and I am constantly relating to her insertion of quirky humor. One of my favorite parts of her writing are her footnotes, which provide fascinating tangent trivia and jokes. Everything is heavily sourced, and she manages to discover things you've never even conceived.

Of course, the things you know and expect are here: dentures, organ transplants, prosthetics. But so much more! For example, a common olden punishment was nasal mutilation. Cutting off a nose served as both pain & humiliation, and a warning to others, and led to many different forms of nasal reconstructions. Who knew? This was a very informative book, teaching me things I didn't know and causing me to share trivia overmuch to those around me, hahaha. Mary tackles some of the subjects from new perspectives, such as WISHING for a prosthetic limb. Also, I found myself viewing some things from the "just because we can, doesn't mean we should" point of view.

Highly recommended!

[Sarah · Rating 5 out of 5]

ARC from the ALA conference.

God, I love Mary Roach. I can’t think of a single writer I’d rather spend a day with. As always, I laughed, I learned stuff, I got grossed out, and I thoroughly enjoyed the footnotes.

[Sharon · Rating 3 out of 5]

I don’t know if I’ve changed or her writing has become a little more cynical, but I used to be a huge fan and for me this last book felt a little bit flat. I found the flippancy about the organs and the xenotransplantation just a bit too much for me.

[Marika · Rating 5 out of 5]

Review to come, but author Mary Roach delivers again.

* I read an advance copy and was not compensated.

[Jess Firlotte · Rating 4 out of 5]

I learned a lot of weird things from this, especially with the random side notes that were entertaining, but multiple areas required me to repeat them to figure out what was going on and who was being spoken about using collective nouns.

It's fascinating that you have to strap a foot in place during a hip replacement because it will otherwise twist about nearly 180°. That's a fun and also highly horrifying fact.

Favourite Quote:

"Note: [The] Candle must have been incompletely extinguished, as reigniting trick candles did not exist in 1840. The national candle association would like them to go back to not existing, because they sometimes re-light after they're thrown in the trash and proceed to burn down the house. Canada took a step in that direction in 1977, by banning trick candles, along with sneezing powder, certain kites, lawn darts, and fun."

[EB · Rating 2 out of 5]

Thought I would love this one as a scientist but I really wasn’t a fan, some chapters were completely boring imo! The author’s tone kind of just fails to spark interest :/

I did very much appreciate the author shining light on all of the cuts to scientific funding our pos government has been making <3

[Saif Elhendawi · Rating 3 out of 5]

I recently picked up this book, looking for a bit of a break from more serious readings. After reading her previous works, I have become accustomed to her explorations of human anatomy, and I really did enjoy the bizarre medical history she presents here. The book explores the history and future of regenerative medicine, covering everything from the early days of "sculpting noses from brass" to modern xeno-pigsties in China. Roach posits that the human body is "the most complex machine in the world, and the only one for which you cannot get a replacement part from the manufacturer." She has a talent for making clinical subjects approachable with bizarre musings and witty remarks that make her journalistic style enjoyable. I think I have become a bit too cynical though, because I couldn't help but think about the lack of systemic or critical lens that she has for the topic at hand.

What really surprised me was how easily the book detaches medical advancement from the economic base that funds it. Roach travels to a stem cell "hair nursery" in San Diego and a high-tech burn unit in Boston, framing these places as triumphs of human ingenuity. However, she fails to examine who actually has access to these replacement parts. When science treats the human body as a machine needing manufactured parts, those parts become commodities traded in capitalist markets. The reality is that the wealthy elite will have access to bespoke 3D-printed kidneys and "hearts from pigs," while the global working class will continue to sell their actual biological organs to survive. Roach treats regenerative medicine as a universal human triumph rather than an emerging luxury market for the capitalist class. On the bright side, she does critiques the cultural stigmas that hinder medical research. But, even then, I find that Roach is too invested in the novelty of science to see the structural problems behind it. In a chapter talking about the work of Orbis International performing cataract surgeries in rural Mongolia, she really missed out on an easy opportunity to comment on this issue. While restoring sight is objectively beneficial, the framing relies on a dynamic where Western medical charity is positioned as the solution to global health inequalities. It ignores the imperialist wealth extraction that keeps such regions impoverished and reliant on foreign medical aid in the first place. If we have the technology to grow organs from stem cells, but millions die because they cannot afford basic healthcare, the problem is not a lack of scientific advancement. The problem is the artificial scarcity imposed by the state and the private medical industry.

To be fair, one should not expect every single book to have a materialist critical lens or a systematic view. A book can just be a nice package of humor and interesting facts right? Well it can be, for sure, but then forgive me for pointing out that its lackluster in this regard too. The stories within are not as captivating as the ones in Stiff, not as funny as the ones in Bonk and not as informative as the ones in Gulp. So I enjoyed this one the least. Is this because it is worse off than her previous stuff or because I have become more critical? Not so sure. But, I really hope that she shifts her future work towards a better direction.

[Miranda · Rating 4 out of 5]

I have been a fan of Mary Roach for longer than I care to admit. After all, never ask a man his salary or a woman how many books she’s been around to see an author publish. A podcast I like talks about books that give you a case of didjaknowitis. This is what happens when you are reading a book and you cannot stop saying to people, “hey did YOU know?” And you can tell this is a primo quality Mary Roach experience because oh boy did I have didjaknowitis real bad. I was texting my friends, I was chasing my boyfriend around the apartment.

If you have already spent time on the Mary Roach train you know exactly what you’re in for, and if you liked your time there, buckle up. If not, you know what you like and this is probably not for you. It’s not a marked departure from her past work.

If you haven’t yet spent time on the Mary Roach train, allow me to introduce you to Mary Roach, a woman who is just like us, but who has the...gumption? Attitude? Chutzpah? To take her curiosity where the rest of us only dream of. She goes to the cutting edge of science, and then follows the scientists around, badgering them with the questions we only dream of asking. Or offering herself up as a human guinea pig. Anyway, this is not some popular science book written by someone on the sidelines. Mary Roach is in it to win it. Her down to try anything once, can do attitude is why her books are so good. You can start here or anywhere if you think that sounds interesting.

Recommended for people who are still subscribed to National Geographic in their hearts, fans of the podcast Sawbones, and anyone who likes dropping unhinged facts at a cocktail party.
I received an arc in exchange for this honest review.

[Laura · Rating 3 out of 5]

Parts of this were super interesting and other parts dragged on a little for me.

I didn't enjoy it as much as 'Stiff', but maybe that is because it wasn't quite as shocking?! Or possibly I just found the content a little less intriguing.

I will forever find the body to be quite the marvel.

[Hannah]

It's Mary Roach! Of course I loved it! Of course it's delightful!

[Anny · Rating 4 out of 5]

In short, your own parts worked the best. Other human's parts were second best but you'd still need to take immune suppressant drugs to deal with rejection. Animal's parts were the third best thing if you lack human donor, though the efficacy was still fairly on the low side that they serve more as a replacement buffer until you can get the human's part. Artificial parts should be somewhere in between, it depended on the parts mostly, prosthetic and artificial hip might served well enough but artificial lungs was a bit more troublesome.

Growing your own parts was the holy grail and to that extent we've tried growing human parts in pigs. Results remained to be seen. Progress were made on growing liver, kidney and heart, but that was still far away on the horizon. A closer goal might be growing your own insulin producing cells (I forgot the name) or your own hair follicle.

As per traditional Roach, there were plenty of weird and icky things mentioned in the book. I almost skipped the anal sphincter chapter because I thought it was a bad idea to listen to that after dinner, but it turned out to be a very wholesome chapter. I did not really care for the breast and buttock chapter but overall this was a fun and informative book about the current state of some human body replacements.