Melatonin for Nighttime Toilet Trips: A Two-Week Trial

Melatonin reduced nighttime toilet trips in a small, two-week trial in older women. The study offers a short-term result to discuss with a clinician; it does not establish what happens with months of use.¹

The change recorded over two weeks

At a university hospital in Thailand, 60 women over 55 were randomly assigned to melatonin 2 mg daily or placebo, 30 per group. The trial was double-blind. Both groups began with a median 2.3 nighttime urinations per night.¹

The median change was one fewer trip per night with melatonin, versus no change with placebo. The first uninterrupted sleep period increased by a median one hour versus no change. Both comparisons had p values below 0.001. These are group summaries, not a promise of one fewer trip for each person.¹

The published abstract reports comparable adverse events without listing event counts. That brief report and two-week follow-up cannot establish long-term safety.¹

How the urology guideline limits the option

The European Association of Urology² gives a strong recommendation to consider melatonin for up to two weeks in women whose nocturia accompanies sleep disturbance. The recommendation concerns that combination of symptoms and that duration.²

Its trial summary reports no difference in 24-hour urine volume or the proportion produced overnight. Fewer trips should not be read as proof that melatonin makes the kidneys produce less urine.²

The guideline also recommends a three-day bladder diary and assessment for sleep disorders. Evaluation includes current medicines and heart, kidney and endocrine conditions. Ask which part of that assessment applies to your nighttime pattern before choosing a treatment.²

Why the broader research needs caution

A 2024 systematic review found nine studies involving melatonin or the prescription melatonin-receptor drug ramelteon. They included placebo-controlled trials, unblinded comparisons and uncontrolled studies. Different bladder diagnoses prevented a combined statistical estimate. The reviewers judged the evidence insufficient for routine melatonin treatment of nocturia.³

That review describes the Thai trial’s exclusions, including kidney or heart disease, uncontrolled diabetes and medicines affecting sleep or urination, including systemic estrogen. Those exclusions matter if your health or prescription list differs from the participants’.³

The review’s broad conclusion and the guideline’s short-term recommendation answer different questions: routine treatment across nocturia populations, and a limited option when women also have sleep disturbance. Discuss the latter in the context of your own assessment.

Check daytime effects and the product

NCCIH⁴ notes that melatonin can remain active longer in older adults and cause daytime drowsiness. Report morning sleepiness, dizziness or nausea rather than judging the result only by the number of toilet trips.⁴

Bring your medicines and supplements list to the review. People with epilepsy or taking blood thinners need medical supervision with melatonin. Information about long-term supplement safety remains limited.⁴

In the US, melatonin is sold as a dietary supplement and is regulated less strictly than medicines. Some products contain amounts different from their labels. Show the clinician or pharmacist the exact product, strength and formulation you intend to use. A trial’s 2 mg dose does not validate every bottle carrying that number.⁴

Laugh, Sneeze, Jump explains how to keep a bladder diary and includes nighttime trips. Bring that record to the appointment with two specific questions: whether sleep disturbance appears to contribute, and how you will compare symptoms and daytime effects at a planned review.