Pumpkin Seed Oil (PSO) is often marketed for supporting hair health, primarily in relation to hair loss and promoting hair growth. The scientific evidence for this use is limited but not entirely absent. One of the most referenced studies is a 2014 randomized, double-blind, placebo-controlled trial published in "Evidence-Based Complementary and Alternative Medicine." In this study, 76 men with androgenetic alopecia (male pattern baldness) took either 400 mg of pumpkin seed oil per day or a placebo for 24 weeks. The group taking PSO showed a statistically significant increase in hair count compared to the placebo group. The hypothesized mechanism involves PSO's phytosterols, which may inhibit 5-alpha-reductase, the enzyme responsible for converting testosterone to dihydrotestosterone (DHT), a hormone implicated in hair loss.

Beyond this, evidence is sparse. There are no large-scale clinical trials, and most supporting data come from animal models or small human studies. Traditional or folkloric use of pumpkin seed oil for hair health is minimal, with most historical applications focusing on urinary and prostate health. Overall, while early research is promising, particularly for androgenetic alopecia, the current level of scientific validation is weak, and more robust, larger-scale studies are needed to confirm efficacy and determine optimal dosing.