Melatonin and Fertility

What is melatonin, and how does melatonin affect fertility?

Melatonin is a hormone secreted by the brain in response to darkness, which aids in the synchronization of circadian rhythms and the initiation of sleep. The presence of light during nighttime hours can inhibit the production of melatonin.

Sleep is an essential component of human health, and its disruption can lead to or worsen certain medical conditions. The hormone melatonin has a main role in the regulation of sleep and circadian rhythms. Studies have suggested that an imbalance of melatonin levels may be the cause of sleep and circadian disorders. PMID: 34684482

If our sleep is optimized, our brain is able to produce a sufficient amount of melatonin that can facilitate a good night's sleep. We have to have good sleep to create the rhythms for more good sleep! However, certain disruptors can interfere with our sleep and impede the production of melatonin.

A study was conducted on individuals to assess the effects of exposure to room light or dim light during the 8 hours leading up to bedtime. The results of this study suggest that prolonged exposure to electrical lighting in the evening can suppress melatonin levels and shorten the body's perception of night. This disruption of melatonin signaling can have potential consequences for sleep, thermoregulation, blood pressure, and glucose regulation. PMID: 21193540

Follow these tips to keep your melatonin levels healthy and happy! 

  1. Avoid screen time at least 1-2 hours before bedtime. 
  2. At dusk, use blue light filter glasses when looking at a screen, such as using a cellphone, computer, or TV. 
  3. Certain supplements can help but only after consulting with your doctor to know which one is right for you. 

How does melatonin affect fertility? PMID: 25330986

Over the past several years, the detrimental consequences of oxidative stress on fertility have been extensively documented. Research findings demonstrate its deleterious effect on both the number and quality of oocytes and embryos retrieved in in-vitro fertilization (IVF). Melatonin, a hormone secreted by the pineal gland responsible for regulating circadian rhythms, has been shown to possess potent antioxidant properties. Studies have explored its potential contribution to gamete biology. Moreover, clinical studies have suggested that melatonin supplementation in conjunction with IVF could potentially facilitate higher pregnancy rates. 

Melatonin is an effective mitigator of mitochondrial DNA damage, likely as a result of an increase in electron transport efficiency within mitochondria, thus preventing the formation of ROS (reactive oxygen species). In some situations, melatonin may be even more effective at performing this function than specific mitochondrial antioxidants, and this particular characteristic may have relevance to its use in the treatment of infertility and the improvement of oocyte quality and maturity. A recent review demonstrated that melatonin administered orally has the potential to reduce intrafollicular oxidative damage and increase fertilization rates.

The effects of melatonin on sperm quality have been explored, with melatonin receptors being identified in spermatozoa. In accordance with Ortiz et al., the addition of melatonin to semen samples can increase the percentage of progressively motile spermatozoa, as well as the overall motility. Moreover, melatonin has been attributed to inhibiting apoptosis in spermatozoa, thus prolonging sperm survival. All these effects suggest that melatonin could potentially improve sperm quality and boost the chances of successful fertilization. But as a supplement also lowers testosterone, so it is not the route to go for men needing to improve testosterone.

Effects of melatonin on embryo culture media. The impact of melatonin supplementation of embryo culture media in porcine, murine, and bovine systems has been extensively studied, with the overall results demonstrating a beneficial effect on fertility and implantation success. Lower concentrations of melatonin in the in-vitro culture media were found to be more beneficial, as opposed to higher concentrations which had potentially harmful effects. These results suggest that in-vitro supplementation of culture media with melatonin has a notable impact on embryo development and quality.

The effects of melatonin on luteal function have been studied in the context of in-vitro fertilization (IVF). An imbalance of reactive oxygen species (ROS) has been identified as a potential cause of luteal phase defect, and studies have revealed that melatonin supplementation can significantly increase progesterone levels. These findings suggest a potential role for melatonin in the maintenance of a receptive endometrium and the support of early pregnancy; both of which are essential for successful conception.

Infertility treatment is linked to high concentrations of reactive oxygen species, which may impair the quality of oocytes and embryos. Melatonin has the potential to be used as an adjunctive therapy in infertility treatment, given its anti-oxidative property and safety profile. 

In my clinical experience, I have observed the positive influence of melatonin on female fertility. Evidence suggests that melatonin supplementation may improve egg quality. As a result, melatonin is often used in my practice for its potential beneficial effects on fertility.  But talk to us or your own doctor before starting any new supplements!