Love Potions come in many varieties. Their effects can vary from mild infatuation to outright obsession.
Polyjuice Potion
The Polyjuice Potion, which is a complex and time-consuming concoction, is best left to highly skilled witches and wizards. It enables the consumer to assume the physical appearance of another person, as long as they have first procured part of that individual's body to add to the brew (this may be anything - toenail clippings, dandruff or worse - but it is most usual to use hair). The idea that a witch or wizard might make evil use of parts of the body is an ancient one, and exists in the folklore and superstitions of many cultures.
The effect of the potion is only temporary, and depending on how well it has been brewed, may last anything from between ten minutes and twelve hours. You can change age, sex and race by taking the Polyjuice Potion, but not species.
Love Potions
Polyjuice Potion