Pumpkin seeds come from Cucurbita pepo, the same species as the field pumpkins carved at Halloween, along with courgettes and marrows. The flat green seeds, sometimes sold as pepitas, are a nutritious snack in their own right, providing protein, healthy fats, zinc and plant sterols. Pressed, they give a dark green seed oil.
In European herbal tradition pumpkin seed has a long history, and it is traditionally used to support prostate and urinary health, and healthy hair. European herbal regulators recognise pumpkin seed preparations as traditional herbal products for urinary symptoms in men with an enlarged prostate and for an overactive bladder, once a doctor has ruled out anything more serious. In supplements you will see pumpkin seed extract, pumpkin seed oil or Cucurbita pepo seed, often alongside saw palmetto, nettle root or zinc.
Researchers have also looked at pumpkin seed oil and hair. A 2014 randomised, placebo-controlled trial in 76 men with pattern hair loss found that those taking 400 mg of pumpkin seed oil a day had more hair after 24 weeks than those on placebo. It was a single small study, so it is an encouraging signal rather than proof.