Dietary supplement increases anagen hair rate in women with telogen effluvium: results of a double-blind, placebo-controlled trial

Background: Dietary supplements are traditionally used over-the-counter products for the treatment of hair loss. Objectives: We aim to examine the effect of a specific L-cystine, medicinal yeast, pantothenic acid complex-based dietary supplement (Pantogar ® ) on telogen effluvium in healthy women. Methods: A randomized, double-blind, placebocontrolled study was conducted over 6 months in 30 healthy women suffering from telogen effluvium. The efficacy of the supplement was evaluated by means of digitalized epiluminescent microscopy (TrichoScan) performed before treatment and after 3 and 6 months. Additionally, global photographs were taken and evaluated by independent investigators. Results: Active compound led to a statistically significant improvement and normalization of the mean anagen hair rate within 6 months of treatment (p = 0.003), while there was no significant change in the placebo group (p = 0.85). These changes of the anagen hair rates were significantly different (p = 0.008). The appearance of hair growth in the global photographic assessment was judged better in the active compound than in the placebo group. Conclusions: This is the first study performed combining epiluminiscence microscopy with digital image analysis to demonstrate that a dietary supplement influences hair growth. The mode of action is not known, although it seems to result from an induction of anagen. Dietary supplements are traditionally used overthe-counter (OTC) products for the treatment or prevention of hair loss. Typically, they are based on a combination of L-cystine and vitamins, usually of the B-complex group, including pantothenic acid and p-aminobenzoic acid (PABA). The rationale for the use of L-cystine for the treatment of hair loss is based on the biochemistry of cystine metabolism, clinical observations in disorders of cystine metabolism and cystine deficiency and results of animal and human studies. L-cystine, a natural, aliphatic amino acid, is a constituent of keratin. Accordingly, hair contains a high proportion of L-cystine (15.9%). In trichothiodystrophy, there is a deficiency of sulfur-containing amino acids in the hair, resulting in increased brittleness. In homocystinuria, the hair is thin and hypopigmented. In HIV trichopathy, disorders of the cystine-dependent amino acid metabolism and glutathione-dependent detoxification mechanisms lead to dry, fragile hairs, hair loss and premature graying. In the 1960s, the role of L-cystine in the production of wool was investigated and it was found that enrichment of even what appeared to be a normal diet with sulfurcontaining amino acids increased wool production in sheep [1–3]. When considering which dietary supplements could be used for improving hair growth in humans, L-cystine was therefore a candidate. In the early 1990s, studies on the effect of dietary supplements containing L-cystine, in combination with B-complex vitamins and medicinal yeast, a rich natural source of B-complex vitamins, were published, demonstrating improvements in the trichogram (hair pluck test), in hair swelling as a criterion for hair quality and in the tensile strength of the hair fiber [4–6].