The Spartan Guide to Grapefruit Extract

The Claim The breakfast favorite packs a big medicinal wallop, and it’s often prescribed just like a drug. Healthcare practitioners often use grapefruit's juice to treat high cholesterol, atherosclerosis (hardened arteries), cancer, psoriasis, and weight loss, while patients use oil from the skin and extracts from the seed to fight viral, fungal, and bacterial infections.

The Evidence One study found that taking pills made from grapefruit seed extract for 16 weeks cut total cholesterol and improved the ratio of “bad” cholesterol to “good” cholesterol. Separate research notes that, in people with high cholesterol, snacking on one grapefruit a day can reduce total cholesterol, “bad” cholesterol, and triglyceride levels.

For those not so concerned with cholesterol, there's a potential second benefit to eating the fruit. Early research on overweight people suggests that eating one fresh grapefruit a day can speed weight loss.

How to Use It Grapefruit has a long list of drug interactions, so if you’re taking other prescription drugs, talk to your doctor before taking a seed-extract supplement or wolfing down a mountain of citrus. For that reason, many experts recommend the fruit in its essential oil form, says Chris Niedzinski, owner of InnerLink Chiropractic in Wixom, Michigan. “The proteins that cause drug interactions are not in the oil—they are in the fruit,” he says. “Three drops in water sipped through the day will also help increase energy and clarity.”

That said, the medicinal efficacy of grapefruit oil hasn’t been determined. So for the biggest impact, go with the whole fruit.