Melatonin supplements have been found to have potential effects on hormonal balance, primarily due to their influence on the body's natural sleep-wake cycle. Melatonin is a hormone produced by the pineal gland in the brain, which helps regulate the sleep-wake cycle and plays a role in various physiological processes.

When taken as a supplement, melatonin can affect the levels of other hormones in the body. One of the most significant impacts is on the hormone called cortisol, which is responsible for regulating stress responses. Research studies have shown that melatonin supplementation can reduce cortisol levels, particularly in individuals with disrupted sleep patterns or jet lag.

In addition to cortisol, melatonin may also impact other hormones such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH), both of which play crucial roles in the reproductive system. Some studies suggest that melatonin supplementation can affect the secretion of these hormones, potentially influencing menstrual cycles and fertility in women.

It's important to note that the effects of melatonin on hormonal balance can vary among individuals and depend on factors such as dosage, timing of supplementation, and underlying health conditions. Consulting with a healthcare professional is recommended before starting any melatonin supplementation, especially for individuals with pre-existing hormonal imbalances or those taking other medications.

References:

1. Gooneratne, N. S., Edwards, A. Y., Zhou, C., Cuellar, N., Grandner, M. A., & Barrett, J. S. (2014). Melatonin pharmacokinetics following two different oral surge-sustained release doses in older adults. Journal of Pineal Research, 56(4), 426-432.
2. Valcavi, R., Zini, M., Maestroni, G. J., Conti, A., Portioli, I., & Melzi d'Eril, G. V. (1993). Melatonin stimulates growth hormone secretion through pathways other than the growth hormone-releasing hormone. Clinical Endocrinology, 39(2), 193-199.
3. Pandi-Perumal, S. R., Srinivasan, V., Maestroni, G. J., Cardinali, D. P., Poeggeler, B., & Hardeland, R. (2006). Melatonin: Nature's most versatile biological signal? FEBS Journal, 273(13), 2813-2838.