The Unexpected Consequences of Using Melatonin

Dr. Richard Wurtman, a neuroscientist from MIT, introduced melatonin in the hopes of finding a solution for sleep issues in the elderly, whose melatonin receptors become less effective with age. His lab even patented the supplement for this purpose. In a New York Times article, Judith Vaitukaitis, then director of the National Center for Research Resources, stated that the hormone offered hope for a non-addictive, natural agent that could improve sleep for millions of Americans. Despite her enthusiasm, Wurtman himself warned against self-medication with melatonin.

Despite this warning, melatonin has become incredibly popular in recent years. It is inexpensive, widely available, naturally occurring, and considered safe, making it an attractive alternative to prescription pills. It has become a staple in the medicine cabinets of shift-workers, frequent fliers, chronic insomniacs, and naturopaths alike.

Almost 1.3 million American adults have reported taking melatonin, with parents giving it to their children believing it to be a harmless, naturally produced hormone. Although it is natural, the hormone is one of the cloudiest supplements on the market and is not fully backed by incomplete and emerging research. In the U.S., it is available without a prescription as a dietary supplement, but can cause long-term usage to affect natural hormone levels and, ultimately, impede sleep. For kids, the possible side effects are even more concerning.

Our bodies naturally produce melatonin from within ourselves. This hormone is known to regulate our internal clock and circadian rhythms, and is typically taken at bedtime when endogenous levels are rising. It is also used to recover from jetlag, as many frequent fliers claim it helps reset their biological clock to the time zone they are in. While this hormone is endogenous, what is found on pharmacy shelves is exogenous, or originating from the outside. Synthesized melatonin is the most commonly used form and helps aid sleep.

Melatonin has been categorized by the FDA as a dietary supplement, to escape the complicated and extended procedure of research and licensing imposed on drugs and hormones. However, this decision exposes users to potential health risks due to the lack of guidelines on recommended dosages and the lack of warning labels. As a consequence, businesses are selling melatonin in assorted dosages without providing adequate information.

Despite its commonality in pharmacies, research from the Massachusetts Institute of Technology (MIT) has determined that melatonin needs to be taken in limited doses - between 0.3 and 1 milligrams - to be effective. Taking more than the recommended amount can lead to a variety of uncomfortable and disruptive side effects, including drowsiness the next day and potentially damaging effects to hormonal development in children. Dr. Wurtman, an expert in this field, warns that, while it will not endanger the body, taking too much melatonin can make life “miserable”. It may come as a surprise to many, but Michael Grandner, a sleep researcher at the University of Pennsylvania, has revealed that melatonin can lead to fatigue the following day. Of greater concern, especially when it comes to children, is that melatonin can interfere with puberty and interfere with normal hormonal development. Additionally, Grandner has noted that taking melatonin can also disrupt menstrual cycles. Excess melatonin can lead to hypothermia, as body temperature is decreased during melatonin release, as well as increased production of the hormone prolactin, potentially causing hormonal problems, kidney and liver issues in men. 

Occasionally using melatonin can be beneficial in promoting sleep. However, prolonged use can actually worsen insomnia due to an overload of the hormone in the body. This alters how the receptors in the body react, regardless of whether the hormone comes from the body itself or from an external source. Dr. Wurtman cautions that taking melatonin supplements may not be effective in the long run, noting that, with regular use, the brain can become desensitized and be unable to benefit from the hormone even when naturally produced. Furthermore, he notes that, paradoxically, this desensitization can cause insomnia.

Mauricio Farez, an Argentinian sleep researcher, has expressed his reservations about the use of melatonin. He noted that it is difficult to maintain consistent levels of the drug in the body and warned that people should not administer it without consulting a physician.

Dr. Wurtman states that taking melatonin at night offers no significant benefit, as the body already has a high level of it. By comparison, he states that it is like adding only a drop of water to an already full bucket when it is day; this shows that taking melatonin in the daytime is hardly effective.

Although melatonin has not been extensively studied for its immunologic potential, Farez's recent study suggests that it may be useful in managing multiple sclerosis. Furthermore, melatonin is often used to treat certain types of cancer because it can fight tumor cells. Additional research is still needed in order to fully understand melatonin's potential health benefits.

Farez and Wurtman agree that the advantages associated with the use of melatonin in a medical context are greater than the potential risks. However, if it is accessible in stores without supervision or restraint, this could lead to problematic consequences.