Melatonin supplements appear to help with sleep in people with DSWPD, but it’s uncertain whether the benefits outweigh the possible harms. This is based on a clinical practice guideline, a small review, and a more recent study.

Polycystic ovarian syndrome (PCOS): PCOS is a hormonal imbalance caused by your ovaries creating excess male hormones. Melatonin also interacts with biologically female hormones. Research has shown that it helps in regulating menstrual cycles. Foster RG (June 2020). "Sleep, circadian rhythms and health". Interface Focus. 10 (3): 20190098. doi: 10.1098/rsfs.2019.0098. PMC 7202392. PMID 32382406.Arnao, Marino B.; Giraldo-Acosta, Manuela; Castejón-Castillejo, Ana; Losada-Lorán, Marta; Sánchez-Herrerías, Pablo; El Mihyaoui, Amina; Cano, Antonio; Hernández-Ruiz, Josefa (2023). "Melatonin from Microorganisms, Algae, and Plants as Possible Alternatives to Synthetic Melatonin". Metabolites. 13 (1): 72. doi: 10.3390/metabo13010072. PMC 9862825. PMID 36676997.

A decarboxylase with cofactor pyridoxal phosphate (PLP) removes CO 2 from 5-hydroxy-L-tryptophan to produce 5-hydroxytryptamine. [42] PLP forms an imine with the amino acid derivative. The amine on the pyridine is protonated and acts as an electron sink, enabling the breaking of the C-C bond and releasing CO 2. Protonation of the amine from tryptophan restores the aromaticity of the pyridine ring and then imine is hydrolyzed to produce 5-hydroxytryptamine and PLP. [43]located in the center of the brain but outside the blood–brain barrier. Light/dark information reaches the suprachiasmatic nuclei from retinal photosensitive ganglion cells of the eyes [74] [75] rather than the melatonin signal (as was once postulated). Known as "the hormone of darkness", the onset of melatonin at dusk promotes activity in nocturnal (night-active) animals and sleep in diurnal ones including humans. [76] https://www.uptodate.com/contents/pharmacotherapy-for-insomnia-in-children-and-adolescents-a-rational-approach Melatonin levels then continue to increase as your child ages, reaching peak levels right before puberty. Once puberty hits, there’s a steady decrease in melatonin levels until it evens out in the late teens. In all ages after puberty, melatonin levels are higher in women and people assigned female at birth (AFAB) than in men and people assigned male at birth (AMAB). Scientists don’t know enough about the safety of melatonin when used during pregnancy. Until they do more research, it’s best not to use melatonin supplements while pregnant or trying to become pregnant.

Some research indicates that it could be linked to changes in your circadian rhythm caused by seasonal light changes ( 10). Cohen PA, Avula B, Wang Y, Katragunta K, Khan I. (April 2023) "Quantity of Melatonin and CBD in Melatonin Gummies Sold in the US" JAMA. 329 (16): 1401–1402. doi:10.1001/jama.2023.2296. PMID 37097362 Goldstein, C. A. (2023, October 17). Jet lag. In R. Benca & A. F Eichler (Eds.). UpToDate., Retrieved November 9, 2023, from A possible mechanism by which melatonin may regulate weight gain is through its inhibitory effect on leptin. [33] Leptin acts as a long-term indicator of energy status in the human body. [34] By suppressing leptin's actions outside of waking hours, melatonin may help restore leptin sensitivity during the daytime by alleviating leptin resistance. [33] [35] Biochemistry [ edit ] Biosynthesis [ edit ] Overview of melatonin biosynthesis Reiter, Russel J.; Tan, Dun Xian; Rosales-Corral, Sergio; Galano, Annia; Zhou, Xin Jia; Xu, Bing (2018). "Mitochondria: Central Organelles for Melatonin's Antioxidant and Anti-Aging Actions". Molecules. 23 (2): 509. doi: 10.3390/molecules23020509. PMC 6017324. PMID 29495303.Blood pressure drugs. Melatonin might worsen blood pressure in people taking blood pressure medications. Bahrampour Juybari K, Pourhanifeh MH, Hosseinzadeh A, et al. Melatonin potentials against viral infections including COVID-19: current evidence and new findings. Virus Research. 2020;287:198108. Read the patient leaflet for a full list of side effects, cautions, and interactions with other drugs. Vural, E. M., van Munster, B. C., & de Rooij, S. E. (2014). Optimal dosages for melatonin supplementation therapy in older adults: a systematic review of current literature. Drugs & aging, 31(6), 441–451. Reiter RJ, Manchester LC, Tan DX (September 2005). "Melatonin in walnuts: influence on levels of melatonin and total antioxidant capacity of blood". Nutrition. 21 (9): 920–4. doi: 10.1016/j.nut.2005.02.005. PMID 15979282.