Does melatonin help with irregular periods during perimenopause?

Irregular periods are often the first sign that perimenopause has begun, and they can be frustrating to navigate. Some women have wondered whether melatonin, which helps regulate the body's circadian rhythm, might also help stabilize the menstrual cycle. The connection is biologically interesting, but the direct evidence is limited and it is important to set realistic expectations.

Melatonin is produced by the pineal gland and is best known for its role in regulating sleep and the daily light-dark cycle. What is less commonly understood is that melatonin also interacts with the hypothalamic-pituitary-ovarian (HPO) axis, the hormonal communication chain that controls your menstrual cycle. The hypothalamus releases gonadotropin-releasing hormone (GnRH) in pulses, which triggers the pituitary to release LH and FSH, which in turn signal the ovaries. This pulse timing is sensitive to circadian disruption. Research has shown that women who work night shifts or have significantly disrupted sleep patterns often experience menstrual irregularities, suggesting that the circadian system does influence cycle regularity.

Toffol et al. (2014) documented that perimenopausal women have measurably lower melatonin levels than premenopausal women. Whether restoring melatonin through supplementation could help stabilize the HPO axis pulsatility is a reasonable hypothesis, but direct clinical trials examining melatonin for menstrual cycle regulation in perimenopausal women are lacking.

It is also worth being clear about what is driving cycle irregularity during perimenopause. The primary cause is declining ovarian reserve. As the number and quality of follicles decreases, ovulation becomes less predictable. Estrogen and progesterone levels fluctuate more widely. No supplement can reverse this underlying process. What melatonin might do, indirectly, is reduce the degree to which stress and poor sleep are compounding the irregularity by further disrupting the HPO axis. Better sleep and a more stable circadian rhythm create a more favorable hormonal environment overall.

Zhdanova et al. (2001) showed that low-dose melatonin (0.3 mg) improved sleep quality in middle-aged women. If disrupted sleep is amplifying cycle irregularity for you personally, improving sleep architecture through melatonin might have some indirect benefit. However, expecting melatonin to normalize your cycle the way it might normalize your sleep would be overstating what the evidence currently supports.

Studies have used doses ranging from 0.3 mg to 3 mg. Talk to your healthcare provider about the right dose for your situation, particularly because melatonin may theoretically influence reproductive hormone signaling at higher doses.

It is worth setting realistic expectations about the overall goal. Irregular cycles during perimenopause will not return to the regularity of earlier reproductive years, no matter which supplements you take. The perimenopausal transition lasts on average four to eight years before reaching menopause. During that time, managing symptoms and protecting your health more broadly, through sleep, exercise, nutrition, and stress reduction, is a more achievable and meaningful target than restoring cycle regularity. Melatonin fits within that broader health-supporting framework rather than as a cycle-specific treatment.

One practical note: if you are using a cycle-tracking app or fertility awareness during perimenopause, be aware that melatonin may subtly influence basal body temperature readings, since melatonin is involved in the circadian rhythm of core body temperature. This is unlikely to be a significant issue at low doses, but it is worth mentioning to your provider if you are relying on temperature-based cycle tracking for contraceptive purposes. During perimenopause, ovulation remains possible even when cycles are irregular, and pregnancy prevention should not be overlooked.

Because melatonin is an over-the-counter supplement in the US and is not regulated as a drug, quality varies considerably by brand. Look for products verified by a third-party testing organization such as NSF or USP. Known drug interactions include warfarin, immunosuppressants, antidiabetic medications, and CNS depressants. Women with autoimmune conditions should discuss melatonin with their provider before use.

If you are tracking your cycle alongside sleep and other symptoms, having that longitudinal data makes conversations with your provider much more productive. PeriPlan is designed to help you log daily symptoms, cycle patterns, and sleep quality together so you can spot connections over time.

When to talk to your doctor: Irregular periods during perimenopause are usually a normal part of the transition, but some changes need medical attention. See your provider if you are bleeding for more than seven days at a time, soaking through a pad or tampon every hour for two or more consecutive hours, passing large clots, bleeding after sex, or if your periods have stopped entirely for 12 months and then returned. These patterns may indicate conditions such as fibroids, polyps, or endometrial changes that need evaluation beyond lifestyle support.

This content is for informational purposes only and does not replace medical advice. Always consult your healthcare provider about your specific situation.