Hair thinning and quality concerns can have wide ranging impacts on quality of life and cause distress to affected individuals.1,2 An array of factors have been shown to influence hair loss, including but not limited to stress, nutritional deficiencies, illness, hormonal imbalances, and drugs.3–5 Telogen effluvium causes premature entry into the resting phase, resulting in excessive shedding and thinning.3,6 The appropriate operation of cell metabolism during the phases of hair growth increases the resistance of the hair to new external insults, and also stimulates healthy hair growth.7

Nutritional status contributes to hair quality at each phase and can affect the anagen to telogen transition as well as telogen to anagen (ie, new growth) with energy deficiency or other nutritional deficiencies known to impact hair structure, loss, and growth.8 The global market for hair growth supplements to target nutritional considerations has been growing and is projected to have a $2.86 billion USD value by 2031.9

Biotin (vitamin B7) is commonly found in hair growth dietary supplements as it is an essential nutrient that functions as a cofactor required for biotin-dependent carboxylases that act as catalysts in metabolic processes including amino acid catabolism.10 Its function in protein synthesis and keratin production contribute to hair shaft strength.11,12 While rare, biotin deficiency manifests in part as thinning and progressive hair loss.8 Similarly, folate deficiency can cause changes to hair, skin and nails with folate acting as a coenzyme in synthesis of nucleic acids and amino acid metabolism.10 Zinc is an essential nutrient cofactor for enzymes involved in hair growth, and hair loss is a well-established sign of zinc deficiency with regrowth occurring with supplementation.13 Vitamin B12 is another nutrient involved in nucleic acid production that appears to play a role in hair protein production.10

This study aimed to evaluate the effectiveness and tolerability of a novel dietary supplement, Hair Strong Gummies (HUM Nutrition Inc., Los Angeles, California) that contains a blend of B vitamins, zinc, and botanicals in healthy women with self-reported thinning hair.