Studies show that low melatonin levels are linked to erectile dysfunction, but using this hormone as treatment is not yet possible. Learn more.
An issue that often puzzles men is the role of melatonin—the so‑called sleep hormone—in sexual health. **Does melatonin cause impotence, or could it help?** The question makes sense: male sexual health is closely tied to hormonal balance and good‑quality sleep.
With the growing popularity of sleep supplements—especially since Brazil’s health agency (Anvisa) approved melatonin as an over‑the‑counter supplement in 2021—understanding how this hormone acts in the body and what science says about its impact on testosterone, libido and erectile function has become essential.
It’s time to uncover **whether melatonin causes impotence** and how you can keep both your sleep and sexual performance on track. Keep reading.
What is melatonin and what does it do?
Melatonin is a hormone produced by the pineal gland in the brain. It is naturally released at night, when light levels drop, and its main job is to synchronise the circadian rhythm—your internal body clock—helping the body know when to sleep and wake.
The supplement is common among people with insomnia, jet lag or rotating shifts.
Besides improving sleep quality, melatonin acts as an antioxidant and supports the immune system. But **does melatonin cause impotence**?
Melatonin and testosterone production
Testosterone production is central to sexual function, muscle growth and energy. Most of it happens during deep sleep, so anything that disturbs sleep may disrupt this natural process.
A 2000 animal study found that melatonin administration appeared to inhibit testosterone production in rats by affecting the brain–testis hormonal axis. In humans, however, studies remain inconclusive and have shown no significant impact with moderate supplementation.
Does sleep influence male sexual health?
Poor sleep can lower libido, testosterone and even emotional control. Men who sleep badly or have sleep apnoea face a higher risk of erectile dysfunction.
Restorative sleep is tied to hormonal balance. In some contexts, melatonin is being explored as a possible aid, but its use must be individualised and assessed by a health professional.
Remember that, during sleep, men experience nocturnal erections that help oxygenate penile tissues.
Erectile dysfunction & hormones: key players
Erectile dysfunction can stem from organic issues (hormonal, vascular, neurological) or psychological factors. Hormonal culprits include:
- Low testosterone, reducing desire and erection quality
- High prolactin, suppressing sexual appetite
- Elevated cortisol from stress, affecting libido
Scientific evidence: does melatonin cause impotence?
So far, there is no consistent proof that melatonin causes impotence—or treats it.
A 2018 study found that men with erectile dysfunction had lower blood melatonin than controls, possibly because melatonin is antioxidant and oxidative stress contributes to ED.
Though interesting, this was the first study of its kind; further research is needed.
Still, **there is no consensus on how melatonin affects male sexual health**. Clinical use should always involve professional guidance, especially for sleep disorders.
Can long‑term melatonin use harm libido?
Yes. High doses over long periods—without medical follow‑up—may disrupt hormones in susceptible men, leading to tiredness, low desire or even erectile issues. Outcomes vary with age, lifestyle and medications.
Other reported side effects in men
- Daytime sleepiness
- Dizziness or headaches
- Irritability or mood swings
- Reduced libido in specific cases
- Sleep inertia/confusion on waking
Hence, medical supervision is advised to adjust dosage or reassess use.
Sleep‑friendly habits that protect sexual health
- Keep regular sleep–wake times
- Avoid blue light from phones/screens before bed
- Cut evening caffeine and alcohol
- Exercise moderately and consistently
- Opt for light dinners
- Use melatonin only with medical advice
When to see a urologist about erections?
If erectile issues occur in most encounters—even with good sleep—consult a urologist. Only a qualified physician can assess each case and outline the best therapeutic plan.
There is **no proof that melatonin causes impotence**, but supplements should not be taken unsupervised. Sexual health reflects overall balance—seek professional evaluation when in doubt.
Need guidance? Send us your case and a specialist will get back to you.
