Does Sex Actually Help Pass Kidney Stones?

Several randomized controlled trials and multiple meta-analyses suggest that sexual activity genuinely does help pass certain kidney stones, with passage rates roughly doubling compared to doing nothing. The catch is that every study so far has focused specifically on stones lodged in the distal ureter, the final stretch of the tube between kidney and bladder, and all of them instruct participants to have sex or masturbate three to four times a week. So the answer is not a blanket yes for all kidney stones, but for the right stone in the right location, the evidence is surprisingly strong.

What the Trials Found

The first randomized trial to test this idea came out of Turkey in 2015. Patients with distal ureteral stones 6 mm or smaller were split into three groups: one told to have sexual intercourse at least three to four times per week, one given tamsulosin (a standard medication used to help pass stones), and a control group that received neither. After two weeks, about 84% of the sex group had passed their stones, compared to roughly 48% in the tamsulosin group and about 35% in the control group. The sex group also passed stones faster, averaging around 10 days versus 17 to 18 days in the other groups.¹

A second trial, published the following year, enrolled patients with stones up to 10 mm. At two weeks, 82% of the sexual intercourse group passed their stones compared to 53% in the control group. The gap narrowed somewhat by four weeks, reaching about 89% versus 71%, but the sex group still came out ahead, and their average expulsion time was about four days shorter.²

These are not enormous trials. The first had 75 patients total and the second had 56. But the differences between groups were large enough to reach statistical significance, and the pattern has held across additional trials since then. The consistency is what makes the finding hard to dismiss.

What the Pooled Data Shows

When researchers combined the available trials into meta-analyses, the picture became clearer and more robust. An early meta-analysis pooling three trials with 240 patients found that the odds of passing a stone at two weeks were more than six times higher in the sexual intercourse group than in the control group. At four weeks, the odds were still about four times higher. The group having regular sex also needed fewer painkiller injections.³

One wrinkle in that analysis: the average time to pass a stone did not differ significantly between the sex group and the control group when the data was pooled. Individual trials showed faster passage, but when combined, the confidence interval was too wide to call it a reliable difference.³ That sounds contradictory, but it mostly reflects the small sample sizes and variability across studies. More people passed their stone, but the exact timing bounced around.

A more recent and larger meta-analysis including six trials and 535 patients confirmed the overall pattern. The sexually stimulated group had significantly higher expulsion rates at both two and four weeks, shorter average expulsion times, and fewer episodes of renal colic, the intense flank pain that kidney stones cause.⁴ The most up-to-date systematic review, which included eight randomized trials and 755 patients, found that the odds of passing a stone were more than three times higher in the sexual activity group at both two and four weeks.⁵

This Only Applies to Stones Near the Bladder

Every study that has tested sexual activity as a stone-passing strategy has focused on distal ureteral stones, meaning stones that have already traveled most of the way down from the kidney and are sitting in the last few centimeters of the ureter before it enters the bladder. Some studies also include intramural stones, which are lodged right at the junction where the ureter tunnels through the bladder wall. These are the stones most likely to pass on their own regardless, so the question is really whether sexual activity speeds things up and improves the odds.

If your stone is still in the kidney itself, or sitting high up in the ureter near the kidney, there is no evidence that sexual activity will help. Stones in those locations face different anatomical challenges, including tighter segments of the ureter that act as natural chokepoints. Nobody has run a trial on sex for upper ureteral or kidney stones, so recommending it for those cases would be guesswork. Stone size also matters. The original trial capped inclusion at 6 mm, while later trials went up to 10 mm. Stones much larger than that generally require medical intervention anyway, whether lithotripsy (breaking them up with sound waves) or surgical removal.

How It Stacks Up Against Alpha-Blockers

The standard pharmaceutical approach to helping someone pass a distal ureteral stone is medical expulsive therapy, typically an alpha-blocker like tamsulosin. These drugs relax the smooth muscle in the ureter, widening the passage and letting the stone slide through more easily. They are well studied and widely prescribed.

What surprised researchers is that sexual activity appears to work about as well. The first trial found sex outperformed tamsulosin, with passage rates of 84% versus 48% at two weeks. A systematic review and meta-analysis comparing male sexual activity directly against alpha-blockers found that the outcomes were comparable, making it a viable alternative for people who want to avoid medication.⁶

That is a meaningful finding because tamsulosin comes with side effects. Dizziness, low blood pressure, and retrograde ejaculation (where semen flows backward into the bladder during orgasm) are common enough to bother patients. If sexual activity achieves similar results without those side effects, some patients and urologists may see it as a more appealing first option, at least for smaller distal stones.

Masturbation Works Too

One obvious question the early trials left open was whether the benefit came specifically from intercourse or from sexual stimulation more broadly. A 2020 trial addressed this directly by comparing three groups of men: one that masturbated three to four times a week, one that took tamsulosin, and a control group. The results were nearly identical for masturbation and tamsulosin, with about 81% and 80.5% of patients passing their stones, respectively, compared to roughly 43% in the control group.⁷

This is important because it tells us the mechanism is probably tied to orgasm and the physiological events that accompany it, not to the physical mechanics of intercourse itself. It also means the potential benefit is available to people without sexual partners, which broadens who could try this approach.

The Evidence in Women

Most of the early trials enrolled only men, which left a gap in the evidence. A dedicated trial published in 2020 studied women with distal ureteral stones, randomizing them to sexual intercourse three to four times per week versus a control group. At two weeks, 80% of the intercourse group had passed their stones compared to about 51% of controls. By four weeks, the rates were roughly 86% versus 60%.⁸

The women in the intercourse group also needed significantly fewer painkillers, averaging about 1.9 doses per day compared to 2.6 in the control group.⁸ These results closely mirror the findings from the male-only trials, suggesting the effect is not sex-specific. Whatever orgasm does to help move a stone along, it appears to work in both male and female anatomy.

Why Sexual Activity Might Help Move Stones

Researchers have proposed several overlapping mechanisms, though pinning down exactly which one matters most has not been settled. During orgasm, waves of muscular contraction travel through the pelvic region, including the smooth muscle of the ureter. These rhythmic contractions could physically nudge a stone downward, especially one that is already close to the bladder and just needs a push.

Nitric oxide, a molecule the body releases during sexual arousal, also plays a role. Nitric oxide relaxes smooth muscle, and a more relaxed ureter means a wider opening for a stone to pass through. This is essentially the same principle behind alpha-blocker drugs, just achieved through the body’s own chemistry. Endorphins released during orgasm may additionally help explain why patients in the sexual activity groups reported less pain and needed fewer analgesics. The pain relief doesn’t move the stone, but it makes the whole experience more bearable and may reduce the muscle spasms that sometimes trap a stone in place.

There is also a simple hydration factor. Researchers in these trials often recommended adequate fluid intake to all groups, but sexual activity may encourage additional water consumption and generally keep patients more physically active than lying in bed waiting for a stone to drop. None of these mechanisms have been isolated in a way that proves which one drives the effect, and it is likely a combination of all of them working together.

How Often and for How Long

Across every trial, the instruction was consistent: three to four times per week, with follow-up periods ranging from two to four weeks. That frequency appears to be the threshold, and it is what the meta-analyses are built on. Whether having sex once or twice a week would produce a smaller but still meaningful benefit is unknown because nobody has tested lower frequencies.

Most of the benefit seems to emerge within the first two weeks. The difference between the sex group and control group was generally largest at the two-week mark. By four weeks, the control group catches up somewhat because many distal stones pass on their own given enough time. The advantage of sexual activity seems to be that it accelerates passage and increases the overall odds, rather than enabling something that could never happen on its own.

If you are dealing with severe pain, active infection, or a stone that is causing complete obstruction of urine flow, sexual activity is not a substitute for emergency treatment. These trials enrolled patients whose stones were expected to pass spontaneously and who were clinically stable. A stone causing hydronephrosis (backup of urine into the kidney) or signs of infection needs medical attention first.

What the Studies Cannot Tell You Yet

The evidence base, while consistent, has real limitations. All the trials to date come from a small number of research centers, mostly in Turkey and the Middle East. The total number of patients across all trials is still under a thousand. That is enough to establish a plausible effect, but not enough for this to be treated as settled practice the way alpha-blockers are.

There are no trials on stones in the upper or mid-ureter, no trials on stones larger than 10 mm, and no trials in patients who have had recent urologic surgery. The studies also rely on patient-reported compliance, meaning researchers trusted participants to actually have sex or masturbate the prescribed number of times. There is no way to verify that, and some amount of over-reporting seems likely.

Blinding is another issue. You cannot give someone a placebo for sexual intercourse, which means every trial is open-label. Patients in the sex group knew what they were doing, and that knowledge could influence how they reported pain, when they sought follow-up imaging, or other aspects of their care. This does not invalidate the results, since stone passage is an objective outcome verified by imaging, but it adds a layer of uncertainty around softer endpoints like pain scores and analgesic use.

There is also the question of publication bias. Trials with dramatic positive results get published more easily than trials that find nothing. It is possible that some negative studies exist but were never submitted or accepted for publication. The updated meta-analysis with eight trials and 755 patients is reassuring in its consistency, but more diverse research from additional countries and institutions would strengthen the case.⁵

Whether Your Urologist Will Actually Recommend It

Despite the accumulating evidence, sexual activity has not made it into most official clinical guidelines for kidney stone management. The European Association of Urology and the American Urological Association both provide detailed guidance on medical expulsive therapy, fluid intake, and when to intervene surgically, but neither has formally endorsed sexual activity as part of the standard treatment algorithm. That lag between research and guideline adoption is common in urology and medicine broadly, especially when the intervention is unconventional and the evidence comes from a relatively small number of trials.

That said, plenty of urologists are aware of this literature and willing to mention it to patients, particularly when someone is already being managed conservatively for a small distal stone. The risk profile is essentially zero for someone who is medically stable, so the downside of trying is minimal. It is the kind of recommendation that lives in the grey zone between “proven standard of care” and “promising but not yet endorsed,” where shared decision-making between patient and doctor makes the most sense. If you are passing a small stone near the bladder and feeling well enough, bringing it up with your doctor is reasonable. The worst they can say is that they would prefer you stick with tamsulosin, and the evidence suggests you might not even need to choose between the two.