Formulation and Test of Caffeine Hair Tonic Preparations to Stimulate Hair Growth in Guinea Pigs

The study assessed the effectiveness of two caffeine hair tonic formulations with concentrations of 0.001% (Formula 1) and 0.005% (Formula 2) in promoting hair growth on guinea pigs. Formula 1 with 0.001% caffeine was found to be more effective, yielding an average hair length of 18.294 mm, compared to 16.610 mm with Formula 2. The study also confirmed the physical stability of the formulations under varying temperatures and their safety, as they did not cause irritation. Additionally, Formula 1 resulted in a higher number of hair strands, indicating its superior efficacy in stimulating hair growth compared to Formula 2 and controls. However, the number of guinea pigs used in the study was not mentioned, which is a limitation in evaluating the study's strength.