Abstract
BACKGROUND: Hair loss is a common condition affecting both men and women, with significant psychosocial impact. While oral supplements are marketed to improve hair growth, their clinical efficacy remains debated. This systematic review aimed to evaluate the effectiveness and safety of commercial oral nutraceuticals for hair growth. METHODS: For this systematic review, a comprehensive search was undertaken in PubMed, Embase, Cochrane CENTRAL, and Web of Science. Eligible studies included randomized controlled trials (RCTs), open-label trials, and proof-of-concept studies evaluating oral supplements in adults (≥ 18 years) with alopecia or hair thinning. Primary outcomes included objective measures including hair counts, density, growth rate, tensile strength, and pull test. Secondary outcomes were investigator/patient assessments and adverse events. RESULTS: A total of 14 studies, including 967 participants, were included. Supplements assessed included Ceramosides, Nutrafol, Nourkrin, Lambdapil, Viviscal, Forti5, GFM oral supplement, and Cynatine HNS. Most trials were RCTs with durations of 12 weeks to 12 months. Meta-analysis demonstrated significant improvements with oral supplements versus placebo: reduced telogen hair density (mean difference [MD] -5.91, 95% confidence interval [CI] -6.74 to -5.08, p < 0.00001), increased anagen hair density (MD 10.48, 95% CI: 8.81 to 12.14, p < 0.00001), and reduced telogen proportion (MD 3.08, 95% CI: -3.35 to -2.81, p < 0.00001). Similarly, significant differences were observed regarding anagen proportion, elongation, and hairs extracted on a pull test (p < 0.00001 for all). Total hair count showed no significant difference (p = 0.06). Patient-reported outcomes consistently favored supplements, reporting improved thickness, reduced shedding, and better satisfaction. Adverse events were minimal, and safety profiles were favorable. CONCLUSIONS: In conclusion, supplements show promising preliminary results, but more rigorous, independent research is needed to confirm these findings.