Sloth Hair: The New Medical Miracle?

By Joelle Renstrom | Published

This article is more than 2 years old

Sloths are one of those animals that are so ugly they’re cute, so lazy they’re unstoppable, so slow they’ve sped to the spotlight (those of you who watch Ellen know what I’m talking about). But it turns out that these weird creatures that spend their lives hanging upside down might actually be able to save lives — or, more specifically, their hair might. A new study published in PLOS ONE reveals that the hair of three-toed sloth contains special fungi with incredible immunities to cancer, parasites, and bacteria.

Sloths are pretty hairy beasts, and it turns out that their hair grows in two layers. The outer layer is the one with the medicinal properties, as it’s full of “ubiquitous green alga,” which was previously thought to help the sloth camouflage, but is now thought to promote the growth of helpful bacteria that helps sloths stay healthy, driving down the cost of sloth health insurance. It also provides a home for worms, larvae, and roaches, but hey, those disgusting insects need some tasty bacteria too.


Gleaning medical benefits from fungi is an old trick, dating back to the 1928 discovery of Penicillin. Less than 2% of the world’s fungi have been identified, so the four scientists who conducted the study, two of whom are based in Panama and two of whom are based in the U.S., are making it a priority to try and discover and catalog more of the five million species of fungi out there, many of which are likely to have medicinal properties. Scientists gathered fungi from the outer layer of the hair of nine sloths, from which they derived 84 fungal isolates. They performed analyses and genetic screening that revealed a bioactive ingredient that combats “vector-borne” diseases, including malaria, bacterial infections, and breast cancer.

The scientists conducted their research at the Smithsonian Tropical Research Institute in Panama, which has a high population of sloths, and may soon have a high population of medical researchers. These promising initial results will almost certainly prompt further studies that could lead to the development of new treatments and drugs. Sloths are an endangered species, mostly due to humans chopping down the South and Central American rain forests; poaching is a problem as well, which hopefully won’t increase when word of the sloths’ miracle hair gets out. But if that happens, I’m sure Veronica Mars will get right on the case.