You’ve seen them by the cash register at the gas station: “male enhancers” with alarmingly virile-sounding names. “Who buys that stuff?” you might say, chuckling nervously. Or you might say, “Does that stuff really work?” or “Isn’t that stuff dangerous?”

Prepare to have all those burning questions answered: a recent study published in the Journal of Sexual Medicine set out to learn how many men use nonprescription supplements to boost their, uh, personal abilities. The researchers also wanted to learn what’s in those pills, if the pills actually work, and if they’re safe to take. 

So who buys that stuff? A lot of people. Sexual health issues like erectile dysfunction are extremely common; the urologists who conducted the study estimate that between 40 and 70 percent of men will experience sexual dysfunction at some point in their lives. There are drugs for some conditions, but drugs are expensive and can involve terribly uncomfortable conversations with the doctor. “Natural” remedies, on the other hand, are available—without discussion—at any convenience store, or online from any spammer.

Over-the-counter penis pills are classified as dietary supplements, which means there’s no regulation and no monitoring of their ingredients, efficacy, or safety. 

What’s in them? Some of these “natural” supplements may contain herbs like ginseng, ginkgo biloba, or Epimedium grandiflorum, commonly known as "horny goat weed." Others are made with amino acids or hormones. Some are mineral-based. And some are laced with illegal drugs. 

To clarify: the researchers found that some products marketed as “natural” actually contained traces of phosphodiesterase-5-inhibitors (PDE5Is), a class of ED drugs that includes Viagra. Viagra is perfectly legal if you have a prescription, but mixing it into something else and selling it over the counter is illegal in the U.S. It’s also unsafe, senior author Ryan Terlecki said in a press release. A prescription is a doctor’s assurance that the drug should be OK for you to take. Without it, you run the risk of dangerous medication interactions and unintended consequences to your health. 

Do the pills even work? Some might. Others are useless. But the researchers concluded that none of the pills packaged as “enhancers” have been clinically tested. There’s no evidence that they’ll do you any good, and some of the ingredients could actually cause you harm. One thing's for sure: They're not worth the money. "Patients are paying more than $5 per day to take products with no proven effectiveness," Terlecki said.  

Gentlemen, spare yourselves the heartache. If you’re unsatisfied with your sex life, talk to your doctor. Trust us: They’ve heard everything.