Most of us have heard about melatonin. It is a hormone produced primarily from the pineal gland and helps control of our circadian rhythm. We now know that melatonin serves many other purposes within our bodies, which includes serving as a potent anti-oxidant.
Melatonin has long been recognized as an important factor in seasonal reproduction in many animals. We now understand that melatonin is
involved in many factors of human reproduction including the regulation of female reproductive hormones and ovulation.
What are the effects of melatonin?
Melatonin has been reported to have multiple effects on hormone production including increased and/or deceased:
- Thyroid hormones (T4 and T3)
Melatonin supplementation may actually interfere with ovulation in some patients.
In men, decreased libido, as well as diminished sperm count and motility have been reported. These are reversible once melatonin is discontinued.
Research in animal models provides us with evidence of the importance of melatonin in oocyte (egg) maturation and development. A number of events
within the developing mammalian follicle are influenced by melatonin. Melatonin is found in follicular fluid. The largest follicles, typically the most mature, have the highest concentrations of melatonin.
In both animal models and in human follicular fluid obtained during an IVF cycle, melatonin is at its highest concentrations in mature follicle. Supplementation with oral melatonin has been shown to increase the melatonin levels in human follicular fluid. It is thought that melatonin may protect the egg from oxidative stress.
There are now at least a half-dozen studies looking at melatonin supplementation in women and IVF. Most are in combination with other supplements such as Myo-inositol, folic acid or vitamin E. Reported benefits in patients with low/poor oocyte quality in a prior IVF cycle include:
- Improved oocyte quality and maturity
- Improved fertilization rates
- Improved number of high-quality embryos
- Reduced fragmentation of embryos
- Increased implantation rates
- Higher pregnancy rates
While studies in humans show promising results, it remains unclear if live birth rates will actually be improved. Whether melatonin supplementation will benefit infertile women not utilizing IVF remains unknown.
My take on melatonin and IVF:
1. Melatonin has multiple effects on our health, sleep and reproduction.
2. The human studies published utilizing melatonin to improve oocyte quality/pregnancy rates are with IVF.
3. An oral dose of melatonin 3 mg at bedtime is the most commonly studied dose used to enhance oocyte/embryo quality.
4. The time needed to be on melatonin before its maximal benefit on oocyte/embryo quality remains to be determined.
6. Melatonin is a very safe supplement and appears to be non-toxic at typical doses. Be sure to discuss any medications you are currently taking with your health care provider before starting melatonin.
7. Common side effects of melatonin include vivid dreams or nightmares, nausea, fatigue and irritability.
8. Further clinical trials are needed to help us understand the proper dose, timing and application of melatonin to enhance fertility.