Does Biotin Actually Help Hair Growth?
It's the single most common ingredient on a hair-growth supplement label — and the research behind it is much thinner than the marketing suggests, unless you're actually deficient. Here's what NIH and dermatology research really shows.
We've already asked the broader question of whether hair-growth gummies work at all. This one narrows in on the specific ingredient that shows up on almost every competing product's label, and the reason it's worth checking on its own: biotin's reputation as "the hair vitamin" is bigger than what the actual research supports.
Where biotin's hair-growth reputation comes from
Per the National Institutes of Health's Office of Dietary Supplements, biotin is a B vitamin that plays a real role in producing keratin, the structural protein that makes up most of the hair shaft. Genuine biotin deficiency does cause hair loss, along with skin rashes and brittle nails — that connection is real and well established. The question is what that means for someone who isn't deficient, which describes most people taking a hair-growth supplement.
The finding that matters most. A systematic review published in the Journal of Clinical and Aesthetic Dermatology examined every published case where biotin supplementation was reported to improve hair outcomes. In every one of those cases, there was an underlying biotin deficiency, biotinidase deficiency, or an inherited condition that impairs biotin absorption. No randomized controlled trial has demonstrated that biotin supplementation grows hair in a healthy, non-deficient adult.
Why deficiency is the deciding factor
Per NIH's own fact sheet, biotin deficiency is genuinely rare in the United States — most people get enough from a normal, varied diet, since biotin is present in a wide range of common foods. That rarity is exactly why the research keeps landing the same way: biotin supplements reliably help the small number of people who are actually low on it, and the evidence doesn't support a benefit beyond that group. The current clinical recommendation, per the same dermatology review, is that biotin should not be routinely recommended for hair loss in the absence of a documented deficiency.
Where this matters for Folly Nutrition's gummies specifically
Our full Hair Growth investigation found that Folly Nutrition's own gummies center on a different combination — MSM, zinc, and B-vitamins — cited honestly at the ingredient level against a real, independently registered clinical trial (ClinicalTrials.gov NCT06174441). That's a meaningfully different, more defensible approach than leading with a biotin megadose, which is the pattern many competing hair-growth gummies use specifically because "biotin" tests well with consumers, not because the deficiency-driven evidence supports it for most buyers.
Biotin genuinely supports hair health — for the relatively small number of people who are actually deficient. For everyone else, the current research doesn't show a hair-growth benefit from supplementing beyond what a normal diet already provides. If a product's entire pitch rests on biotin content alone, that's worth knowing before you buy it expecting a general hair-growth effect.
See the full Folly Nutrition investigation — the real clinical trial behind its actual formula, and two caveats worth knowing before you buy.
Read the full Hair Growth investigation →Sources
- NIH Office of Dietary Supplements — Biotin, Health Professional Fact Sheet
- Journal of Clinical and Aesthetic Dermatology — Biotin for Hair Loss: Teasing Out the Evidence
Not medical advice. Talk to a real clinician if you're experiencing hair loss, especially to rule out an underlying deficiency or condition before starting any supplement. Questions about this piece? Email contact@healthyhealthsecrets.com. See also our About page and affiliate disclosure.