Is Pumpkin Seed Oil More Effective as a Capsule Supplement or as a Topical Scalp Treatment?

No study has compared pumpkin seed oil capsules with pumpkin seed oil applied to the scalp. The only human trial used capsules taken by mouth. Scalp application has only been tested in mice. So there is no evidence that either form works better than the other.

Capsules: one human trial

In a 24-week trial in South Korea, 76 men with mild to moderate androgenetic alopecia took either 400 mg a day of a branded pumpkin seed oil capsule (Octa Sabal Plus) or a placebo (Cho et al., 2014). Mean hair counts rose by 40% in the pumpkin seed oil group and by 10% in the placebo group. Hair thickness did not differ between the groups. Side effects were few and similar in both groups.

The capsules were supplied by Dreamplus Co., Ltd., which also funded the study and held the randomization codes. The trial did not measure DHT. The authors called it a "first-stage study" that needs to be repeated.

Scalp application: one mouse study

Researchers in Iran applied pumpkin seed oil (5% or 10%) to the backs of mice, after removing their hair, together with a testosterone solution to slow hair growth, six days a week for three weeks (Hajhashemi et al., 2019). The 10% oil improved hair growth scores. The share of follicles in the growth (anagen) phase was about 75% with 10% oil, 91% with 2% minoxidil, and 44% with testosterone alone.

Mouse skin and hair cycles differ from the human scalp. No trial has tested pumpkin seed oil on the scalp in people.

What this means

• Neither form has good evidence behind it, and they have never been compared.
• The capsule result comes from one small, supplier-funded trial of one branded product, in men only.
• Pumpkin seed oil is not an approved hair-loss treatment.

If you are thinking of using it alongside a prescribed hair-loss medicine, ask a doctor or pharmacist first.

References

Cho, Y. H., Lee, S. Y., Jeong, D. W., Choi, E. J., Kim, Y. J., Lee, J. G., Yi, Y. H., & Cha, H. S. (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. PMID 24864154. https://doi.org/10.1155/2014/549721

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. PMID 31763209. https://pubmed.ncbi.nlm.nih.gov/31763209/