Melatonin has been used as a dietary supplement for nearly two decades, but many doctors have been skeptical of its safety. However, within the past few years, scientific studies have been completed that prove melatonin provides several health benefits. In addition, these studies have also shown that adverse melatonin side effects are absent or only minor in most people.
Melatonin is a naturally produced hormone that is becoming increasingly popular as a dietary supplement. In mammals, melatonin is secreted by the pineal gland in the brain, and it regulates sleep cycles and circadian rhythm. When taken orally as a supplement, it has been proven to treat several types of sleep disorders. From the research conducted on sleep disorders, melatonin was later found to produce a number of additional benefits, including all of the following:
- Melatonin is a powerful antioxidant, reducing free radicals in the body.
- Melatonin enhances cancer treatment and may help reduce the risk of cancer.
- Melatonin reduces the effects of jet lag and overnight work shifts.
- Melatonin has been found to improve memory and provide relief from some of the effects of Alzheimer’s disease.
Studies about Melatonin Side Effects
The two definitive studies on melatonin side effects were performed on patients taking melatonin for sleep disorders or for secondary sleep disturbances caused by other primary disorders. Both of the studies were performed by researchers at the University of Alberta, with one published in 2005 and the other published in 2006. The conclusion reached by these studies is that melatonin is safe for short-term use of up to three months with negligible adverse side effects.
It is important to note that negligible adverse side effects are for short-term, low-dose melatonin use. Doses higher than 3 mg per day or at a frequency longer than 3 months may present minor side effects. The most commonly reported side effects of melatonin at this dosage and frequency are as follows:
- Minor nausea
- Morning grogginess
- Slight irritability upon waking
- Vivid, intense or frequent dreams
Melatonin is also contraindicated in people with certain medical conditions. Those with autoimmune disorders may experience stronger symptoms from immunomodulation. In addition, a study at Penn State College of Medicine suggests symptoms due to a rare condition causing decreased blood pressure or blood flow in the brain may be exasperated by melatonin supplements.
Finally, it is important that everyone is aware that sleepiness may occur after taking a dose of melatonin, so it is not recommended to drive or operate heavy machinery.