You’re a man. You develop a kidney stone. Ouch. It’s not too large, so it’s the kind that sometimes passes on its own. Your doctor gives you three choices…

• Just wait and hope that it passes.

• Take a prescription medication such as tamsulosin (Flomax), which relaxes muscles in the bladder, so stones can pass more easily.

• Have sex three or four times a week.

And the winner is…sex! In a study published in the journal Urology, 75 men with moderate-sized kidney stones were put into one of the three groups above. The results…

• 26 of the 31 men in the “have sex” group passed a kidney stone. That’s about 84%. It took an average of 10 days.

• 10 of the 21 patients in the Flomax group—about 48%—passed a stone. It took an average of 17 days.

• Only eight of the 23 patients in the control group—about 35%—passed a stone. It took an average of 18 days.

Of course, the men didn’t actually get to choose which group to be in—they were randomly assigned to a group, to make it a more reliable study.


Before you call your friend who just got diagnosed with a kidney stone and give him the good news, be aware that this unique treatment is appropriate for only certain kinds of kidney stones. Stones that are larger than seven millimeters (mm) in diameter (a little more than one-quarter inch) are less likely to pass on their own, and those over 10 mm almost never do. These larger stones are generally treated with extracorporeal shock wave lithotripsy, in which shock waves from outside the body are targeted to the stone (or stones) to break it up so it can pass.

In this study, the average stone size was about 5 mm. These men also had stones on the lower end of the ureter—the tube that runs from the kidneys to the bladder. Kidney stones stuck in the middle of the ureter do pass on their own, but slightly less often, on average, than those lower down.

So these were the right guys for this experiment. How did it work? One urologist commenting on the study speculated that nitric acid, which is released to create an erection, relaxes the ureter, so stones may pass more easily. Male orgasm itself may also relax the muscles of the ureter.

The study prescribed sex with a partner, so there’s no data on whether masturbation may also help pass kidney stones, although it’s reasonable to assume that it may. And don’t worry about passing a stone during sex—since kidney stones come from the bladder, it’s not going to happen, as this episode of the TV show The Doctors so gleefully points out.

So…if you have a kidney stone—or have a friend who has one—and it’s not too big…and you’re not in unbearable pain…and you have a willing partner, go ahead and check in with your doctor about the kidney stone “sex cure.” And if you don’t have a partner who can help with your multiple weekly “treatments,” there’s probably no harm in, well, taking things into your own hands. Frequent ejaculation is already known to help protect the prostate from cancer, and for both men and women, having sex more than once a month is linked with both marital and personal happiness.

When you start to sweet talk your partner, explain that it’s doctor’s orders. Let us know how that goes…