Can pumpkin seed oil be safely combined with other hair growth ingredients like minoxidil or biotin?

Hair loss is a concern that drives many to explore multiple interventions simultaneously. Among these, pumpkin seed oil (PSO), minoxidil, and biotin are often highlighted. To critically evaluate their combination, it is essential to understand not only their individual mechanisms but also the empirical evidence regarding their interaction and efficacy.

Pumpkin seed oil contains phytosterols, fatty acids, and antioxidants, which are thought to influence hair growth indirectly. The most cited mechanism is the potential inhibition of 5-alpha-reductase, the enzyme responsible for converting testosterone into dihydrotestosterone (DHT), a key factor in androgenetic alopecia. A clinical trial conducted in 2014 involved 76 men with mild to moderate androgenetic alopecia who received 400 mg of PSO daily for 24 weeks.

Hair counts and thickness were assessed using phototrichography and standardized photographs, revealing approximately a 40% increase in hair count compared to 10% in the placebo group. While promising, this study is limited by its sample size and gender specificity. Animal studies corroborate these findings, showing that topical PSO can counteract testosterone-induced hair growth suppression in mice over three weeks. The evaluation focused on the percentage of hair follicles in the anagen phase, a critical growth phase of hair follicles, which increased significantly compared to controls.

Minoxidil's Role in Hair Growth

Minoxidil is a vasodilator that indirectly promotes hair growth by stimulating follicular proliferation and extending the anagen phase. Its efficacy has been demonstrated in multiple trials, with mechanisms involving potassium channel activation in dermal papilla cells and increased local blood flow. However, minoxidil’s effects are transient, and cessation often results in hair reverting to baseline within months. Biotin, a water-soluble B-vitamin, contributes to keratin synthesis. Yet, high-quality evidence for its effect on hair growth in non-deficient individuals is sparse. Most studies are anecdotal or involve small cohorts, suggesting benefit primarily in cases of actual deficiency. Excessive biotin intake may also interfere with lab assays, highlighting the need for caution.

Evidence for Combination Therapies

The potential synergy between PSO and minoxidil has been explored, albeit in limited studies.

A 2025 trial randomized adults with androgenetic alopecia to receive a supplement containing pumpkin seed extract, Serenoa repens extract, and cysteine alongside 5% topical minoxidil for 24 weeks.

Evaluations using global photographic scales showed a statistically significant improvement for the combination group compared to minoxidil alone. Mild dermatitis was reported, suggesting acceptable tolerability. Critically, the study combined multiple active compounds, making it difficult to isolate the effect of pumpkin seed extract alone. Furthermore, no high-quality trials have rigorously tested the combination of pure PSO, biotin, and minoxidil.

The evidence is hampered by small sample sizes, short durations, and variability in PSO formulations. Effects may differ based on concentration of phytosterols and fatty acids. While mechanistically plausible, these interventions’ combined efficacy cannot be conclusively stated. Biotin supplementation appears safe but offers limited benefit for individuals without deficiency. Minoxidil remains the best-studied intervention, yet results are reversible upon discontinuation.

Current evidence suggests that combining pumpkin seed oil with minoxidil is likely safe and may enhance hair growth outcomes modestly, although the magnitude of effect remains uncertain. Biotin can be added safely if deficiency is suspected, but robust evidence for additive benefit in a general population is lacking. Overall, the combination of these interventions represents a plausible, though not fully validated, strategy for supporting hair growth.

References

Cho, Y. H., Kim, M. K., Lee, S. H., Byun, S. J., & Ahn, K. J. (2014). Effect of pumpkin seed oil on hair growth in men with androgenetic alopecia: A randomized, double-blind, placebo-controlled trial. Evidence-based Complementary and Alternative Medicine, 2014, 549721. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4017725/

Hajhashemi, V., Rajabi, P., & Mardani, M. (2019). Beneficial effects of pumpkin seed oil as a topical hair growth-promoting agent in a mice model. Avicenna Journal of Phytomedicine, 9(6), 499-504. https://pdfs.semanticscholar.org/bf6a/d0addb0b607037be4b700d08324974cb90de.pdf

Messenger, A. G. (2004). Minoxidil: Mechanisms of action on hair growth. Journal of Investigative Dermatology Symposium Proceedings, 9(1), 134-136. https://pubmed.ncbi.nlm.nih.gov/14996087/

Starace, M., Milani, M., Cedirian, S., Rapparini, L., Quadrelli, F., et al. (2025). Efficacy of oral supplementation with Serenoa repens, pumpkin seed extract and cysteine combined with topical 5% minoxidil lotion versus topical minoxidil alone in androgenetic alopecia: A randomized assessor-blinded superiority trial. Gavin Publishers. https://www.gavinpublishers.com/assets/articles_pdf/Efficacy-of-Oral-Supplementation-with-Serenoa-Repens-Pumpkin-Seed-Extract-and-Cysteine-Combined-with-Topical-Minoxidil-5-Vs-Topical-Minoxidil-5-Alone-in-Androgenic-Alopecia-A-Randomised-Assessor-Blinded-6-Month-Superiority-Trial.pdf

Yelich, A. (2024). Biotin for hair loss: Teasing out the evidence. Journal of Clinical and Aesthetic Dermatology. https://jcadonline.com/biotin-for-hair-loss-evidence/