Targeting Side Effects Associated with Androgen Deprivation Therapy Using Melatonin: A Randomized Trial on Hot Flashes and Sexual Health in Prostate Cancer Patients.
Hosseini A, Etedali A, et al. • Asian Pacific journal of cancer prevention : APJCP • 2026
Melatonin (3 mg twice daily for four weeks) significantly improved quality of life scores and reduced mild hot flash frequency in prostate cancer patients undergoing androgen deprivation therapy, though its impact on sexual function remained inconclusive.
Key Findings
Results
Melatonin supplementation produced a statistically significant improvement in overall quality of life as measured by FACT-P scores within the melatonin group.
Patients received melatonin 3 mg twice daily for four weeks
FACT-P (Functional Assessment of Cancer Therapy-Prostate) questionnaire was used to assess quality of life
Improvement in FACT-P scores reached statistical significance within the melatonin group (P < 0.05)
The placebo group did not achieve similar statistically significant improvements
41 total prostate cancer patients were enrolled in this randomized, double-blind, placebo-controlled trial
Results
Melatonin significantly reduced the frequency of mild hot flashes by week four of treatment.
The most pronounced effect was observed in the reduction of the frequency of mild hot flashes in the melatonin group
Significant improvements in mild hot flash frequency were noted by week four (P < 0.05)
Hot flash symptoms were assessed using the Hot Flash Diary
Hot flashes were a qualifying symptom for enrollment, as all patients experienced hot flashes or sexual dysfunction due to ADT
The treatment duration was four weeks
Results
Erectile function scores increased modestly in both the melatonin and placebo groups, but neither reached statistical significance.
Sexual function was assessed using the International Index of Erectile Function (IIEF)
Erectile function scores increased in both groups (P > 0.05)
The improvement in erectile function did not reach statistical significance in either group
The authors concluded that melatonin's impact on sexual function remains inconclusive
Both groups showed modest improvement, suggesting a possible placebo effect or natural fluctuation
Results
Melatonin at 3 mg twice daily was well tolerated with no clinically significant adverse events reported over the four-week study period.
No clinically significant adverse events were reported in the melatonin group
The dose used was 3 mg twice daily
Treatment duration was four weeks
The study was conducted at the Hematology-Oncology Center of Omid Hospital in Isfahan, Iran, between October 2019 and October 2020
The tolerability finding supports melatonin's potential as an adjunct therapy in this patient population
Methods
This study enrolled 41 prostate cancer patients experiencing hot flashes or sexual dysfunction secondary to androgen deprivation therapy.
Study design was a randomized, double-blind, placebo-controlled clinical trial
41 patients were randomly assigned to melatonin or placebo arms
Eligibility required experiencing hot flashes or sexual dysfunction due to ADT
The study was conducted in light of the increasing incidence of prostate cancer among younger males
The trial ran from October 2019 to October 2020
What This Means
This research suggests that melatonin, a hormone commonly associated with sleep regulation, may help reduce some of the uncomfortable side effects that prostate cancer patients experience when undergoing androgen deprivation therapy (ADT). ADT is a common treatment that lowers testosterone levels to slow prostate cancer growth, but it often causes hot flashes, sexual problems, and reduced quality of life — symptoms similar to menopause in women. In this small clinical trial of 41 patients in Iran, those who took 3 mg of melatonin twice a day for four weeks reported significantly better overall quality of life and fewer mild hot flashes compared to those who took a placebo.
However, the study found no significant improvement in erectile function for patients taking melatonin — both the melatonin and placebo groups showed modest, non-significant increases in erectile function scores, making it unclear whether melatonin offers any real benefit for sexual health in this context. Importantly, melatonin appeared to be safe and well tolerated, with no serious side effects reported during the four-week period.
This research suggests that melatonin could be a low-risk option to help manage vasomotor symptoms (like hot flashes) and improve quality of life for men on ADT, but the study was small and short in duration. The authors call for larger, longer trials to confirm these findings before melatonin can be formally recommended as part of supportive care for prostate cancer patients.
Hosseini A, Etedali A, Darakhshandeh A, Mehrzad V, Sharifi M, Bariuti Z, et al.. (2026). Targeting Side Effects Associated with Androgen Deprivation Therapy Using Melatonin: A Randomized Trial on Hot Flashes and Sexual Health in Prostate Cancer Patients.. Asian Pacific journal of cancer prevention : APJCP. https://doi.org/10.31557/APJCP.2026.27.2.453