Low Dosage Retinol and L-Cystine Combination Improve Alopecia of the Diffuse Type Following Long-Term Oral Administration

In a study conducted in 1989, a combination therapy of low dosage retinol, L-cystine, and gelatin was tested for its effectiveness in treating diffuse alopecia. The research included a pilot study with 36 patients and a double-blind study with 47 patients. Results showed significant improvements in hair health, with the pilot study reporting an 8.3% reduction in the telogen rate, an 11% increase in the anagen rate, and a 6.9% increase in hair density. The double-blind study further confirmed these findings, showing a 13.5% decrease in the telogen rate and an 8% improvement in the anagen rate, with no changes observed in the placebo group. Additionally, the percentage of dysplastic anagen hairs improved by 7.4%. No systemic side effects were detected, suggesting that long-term oral therapy with this combination could be beneficial for diffuse hair loss.