Placenta shampoo is a type of shampoo which can contain either plant or animal products. Manufactures claim that the protein added to the shampoo will make hair shinier, but there is insubstantial evidence for this claim. Placenta shampoo, though it has undergone occasional revivals since the 80s, is popular primarily in Spanish-speaking countries. Some major retail stores have marketed placenta shampoo towards the US Hispanic market.
Many people may get squeamish reading the word "placenta" on a shampoo bottle. Some people wonder if human placenta was used in the making of the shampoo. It's actually sheep placenta that is used in some brands of shampoo—it is generally believed that the protein from placentas may help coat the hair and make it appear shinier, which some think also occurs when a woman is pregnant. La Bella is one major manufacturer of shampoos containing placenta.
Other types of placenta shampoo contain extracts from vegetables. A plant's placenta is located under the pistil and provides the nutrients from which the fruit develops. Other times, the language on product labels is unclear, and it seems that a plant's "placenta" is any kind of plant essence which will help the hair appear thicker and shinier. There is little proof that either animal- or plant-based placenta shampoos actually help the hair any more than any other product which is meant to add shine to hair, such as oil. Beauty experts who have looked into the chemistry behind many cosmetics state that while placenta shampoo may help, there are many other products that can have the same effect.
The use of placentas in cosmetics dates back to the 1940s, when it became a common additive in the then-unregulated cosmetics industry. It was used as an additive claiming to cure everything from wrinkles to bad hair. Post-regulation has manufacturers limiting the claims to include only that the products can add protein to the hair.
There has been some concern that placenta-based shampoos can cause cancer. This theory, however, has since been disproved. Others are concerned about the overall "cleanliness" of putting the essence of an animal's placenta on hair. The sheep's placenta in commercially manufactured shampoo, however, must undergo a rigorous sterilization process before it can be put into any product.