Sleep is a major issue for millions of people, and over long periods of time, insomnia can weaken one’s constitutional health, immune system, and predispose one to illnesses.  Many people take melatonin to help them regulate their sleep-wake cycle.  Dr. Paula Whit-Enderby, MD, and Judith Balk, MPH, MD,  two researchers,who have devoted much of their professional research careers to the effects of melatonin, have determined that melatonin does much more for women’s health than just getting them into a deep slumber.  It has been revealed that melatonin induces a specific signal transduction cascade (or directs a series of proteins within the cell), which is responsible for melatonin’s differentiating effects inside the cell. In short, melatonin induces certain cells to become bone forming cells called ‘osteoblasts’.  This finding has highlighted the importance of melatonin for bone health in women.

Melatonin is synthesized in the pineal gland in response to light and darkness–when the brain perceives darkness the pineal gland secretes melatonin, which is one factor in the induction of sleep. The primary function of melatonin is to regulate the circadian rhythm that is affected by the light dark cycle.  The researchers have found that melatonin acts in a synergistic way with other hormones.  So, in effect, melatonin can enhance a common intracellular signal, or by combining with another hormone or natural agent, it can enhance the desired outcome of both agents.

Melatonin also plays a major role in improving the circadian rhythm disturbance that menopausal women often experience.  Both researches created a trial to study the specific effects of melatonin called MOPS (Melatonin Osteoporsis Prevention Study published in 2012).  Primary outcome measurements were on bone health in peri-menopausal women.  The results showed a trend toward normalization of bone marker activity (osteoblasts- those cells that build bone and osteoclasts- those cells that break bone down). Secondary outcome measures were sleep quality and menopausal quality of life.  The study used 3 mg melatonin at night and subjects reported significant improvements in physical symptoms of menopause compared to women taking placebo.  Melatonin appeared to lengthen the length of cycles and decrease the number of menstrual cycles.  Women reported feeling better and researchers presumed this was due to  getting better more regulated sleep.

In addition to the effects on sleep and bone health for peri menopausal and menopausal women, melatonin has been shown to have anti-cancer benefits by slowing down cell growth, scavenging for free radicals, reducing levels of estrogen, and enhancing cell adhesion. One thought is that, as women age, there is a dampening of the nocturnal surge in melatonin, changes in light exposure and in hormonal status, which may contribute to diseases like osteoporosis and cancer.

Side effects and toxicity studies of melatonin reveal that it is a safe substance to add to one’s regimen. The most common side effect is sleepiness and grogginess.