Encyclopedia · supplement
Marine protein supplements (Viviscal, Nourkrin)
Branded fish- and shellfish-extract pills with positive but small, manufacturer-linked trials.
What it is
Supplements built on proprietary fish or shellfish extracts, with added vitamins and minerals.
How it works
The makers claim the extracts feed follicles with protein-like building blocks. No mechanism has been demonstrated in people.
What the studies show
- ViviScal, 1992, 40 young men with pattern loss over 6 months: non-vellus hair rose 38% versus 2%. The authors claimed a 95% clinical and histological cure, most had used minoxidil, an erratum was issued, and the effect is implausibly large. Lassus 1992
- Nourkrin, 2006, 55 people over 6 months: a significant positive effect on objective hair growth across causes of hair loss. The abstract gives no numbers. Thom 2006
- Viviscal Extra Strength, 2015, 60 women with self-perceived thinning over 90 days: more terminal hairs (p<0.0001) and less shedding (p=0.002) than placebo. Industry-linked. Ablon 2015
- A systematic review of 30 studies put Viviscal and Nourkrin among supplements with the best, still limited, evidence. Drake 2023
- A meta-analysis of 14 studies (967 people) found pooled benefit for telogen and anagen density but not total hair count. Alanazi 2026
Side effects and safety
Not suitable with fish or shellfish allergy. Usually the most expensive supplement category, about $50 or more a month.
Bottom line
The best-evidenced of the hair vitamins, but with consistent industry ties and no head-to-head test against minoxidil. A fair add-on with realistic expectations, not a replacement for proven treatments. See hair supplement blends. Discuss with a doctor.
Studies 5
Lassus A et al. A comparative study of a new food supplement, ViviScal, with fish extract for the treatment of hereditary androgenic alopecia in young males. 1992
Tested: ViviScal vs fish extract
Result: Non-vellus hair rose 38% vs 2%; authors claimed 95% cure; most had used minoxidil; an erratum was issued.
Read the study ↗Thom E et al. Nourkrin: objective and subjective effects and tolerability in persons with hair loss. 2006
Tested: Nourkrin vs placebo
Result: Significant positive effect on objective hair growth; abstract gives no numbers.
Read the study ↗Ablon G et al. A 3-month, randomized, double-blind, placebo-controlled study evaluating the ability of an extra-strength marine protein supplement to promote hair growth and decrease shedding in women with self-perceived thinning hair. 2015
Tested: Viviscal Extra Strength vs placebo
Result: More terminal hairs (p<0.0001) and less shedding (p=0.002) than placebo; industry-linked product.
Read the study ↗Drake L et al. Nutritional supplements for hair loss: a systematic review. JAMA Dermatol. 2023
Tested: oral supplements including apple nutraceutical and capsaicin-isoflavone
Result: Apple nutraceutical and capsaicin-isoflavone were among the supplements with higher-quality evidence; adverse effects were rare and mild.
Read the study ↗Alanazi R et al. Evaluating the Effectiveness of Commercial Oral Supplements for Hair Growth: A Systematic Review and Meta-Analysis. 2026
Tested: oral hair supplements vs placebo
Result: Gains in anagen density, less telogen and more hairs on pull test; total hair count not significant (p=0.06).
Read the study ↗Related
- Collagen peptidesA protein powder with modest skin evidence and very little for hair.
- Silicon (orthosilicic acid)A silicon supplement that improved strength and thickness of fine hair in one supplier-run trial.
- Hair supplement blends (Nutrafol, Viviscal and similar)Branded multi-ingredient hair vitamins that beat placebo in small, mostly company-linked trials.
- L-cysteineAn amino acid that makes up much of hair keratin, with no controlled hair trial on its own.