When supplements have a place in hair care

People can take a supplement for very different reasons. One needs help correcting a nutritional shortfall. Another is trying a formulation studied for hair growth. A third is addressing a condition contributing to hair loss.

The recommendation should explain the purpose, evidence and way to judge benefit. The word supplement alone tells us little about any of those points.

Start with the intended use

Iron, vitamin B12, vitamin D, zinc and other nutrients can enter a plan when the history and assessment support a need. Food intake, absorption, blood loss and existing supplementation all matter. Excess intake can also create problems.¹

A normal blood result cannot describe every aspect of nutrition. Standard tests are unavailable or imperfect for some ingredients and proposed effects. That calls for a considered assessment of the need and evidence.

Other ingredients are studied for particular conditions. NAC, or N-acetylcysteine, has been tested for hair-pulling disorder. An adult trial found benefit, while a pediatric trial did not find benefit over placebo. The condition and population are essential to interpreting that evidence.^2,3

Give biotin a complete explanation

Biotin is an essential vitamin, and deficiency is very rare. Evidence for routine biotin alone to improve hair in people without deficiency is limited. Very rarely, an inherited condition makes it difficult for the body to use biotin. These conditions are often identified through newborn screening or symptoms in infancy. Biotin deficiency can also cause brittle nails.^4,5

Our patent describes laboratory experiments in which different amounts of biotin increased or reduced hair stem cell numbers. In these experiments, biotin alone did not activate Wnt/beta-catenin. When the cells were stimulated to activate, biotin substantially reduced the Wnt/beta-catenin growth signal, which is required for hair growth.⁶

Biotin can also interfere with some laboratory tests. Tell the clinician and laboratory the product and dose before testing so they can give appropriate instructions.^4,7

The purpose of the supplement determines which evidence matters.

Assess the preparation that was studied

Named preparations help make evidence specific. Our network meta-analysis compared trial results for ALRV5XR, Nutrafol and Viviscal under defined eligibility criteria. These results concern the formulations, populations and study periods included.⁸

The ALRV5XR clinical trials evaluated oral capsules with topical products. Their result describes that regimen and does not isolate the capsule's contribution.⁹

An ingredient study cannot establish the effect of every mixture containing it. A current label also needs comparison with the studied preparation when formulations change.

Make continued use a decision

Bring every product label, dose and reason for taking it. Review overlapping ingredients, other treatments, tolerance and cost. The plan should define the intended benefit and when it will be reassessed.

Limited evidence leaves uncertainty that should be explained. A person's experience deserves attention, alongside the possibility of natural recovery, another treatment effect or a changing condition. That gives continued use a clear basis for review.