We’re going to be real with you here: This is a complicated topic. Hair growth and health are influenced by many factors—both internal and external. That being said, many people swear by hair vitamins and supplements to help support hair health overall.* 

Now, the theory behind hair supplements really comes down to internal structural support. Let’s explain: Hair is made up of keratin1, a type of protein that consists of about 18 amino acids2 including cysteine, proline, threonine, leucine, and arginine. And like most processes in the body, the production of keratin is heavily influenced by free radical damage and oxidative stress—both of which can be eased or neutralized by antioxidants.* 

Ok, but do supplements work? Well, while key nutrients and bioactives can support the synthesis and protection of hair*, clinical studies using supplements in healthy populations are hard to find. (You’ll find some research in people with various nutrient deficiencies, but there’s not much published research on hair supplements for the average person.)

And given that their mechanisms are more about creating optimal conditions for hair health, it’s challenging to track just how much they influence hair growth.

Not to mention: As with the efficacy of any supplement, it comes down to the formulation. But that’s not to say there isn’t robust anecdotal support for hair supplements: While peer-reviewed publications are ideal, lots of anecdotal reports collectively carry merit too.