Question: I take melatonin and it helps, but I am wondering if it is safe?
Answer: Melatonin is a hormone secreted by the pineal gland in the brain. It helps regulate other hormones and maintains the body’s circadian rhythm, which is the internal 24-hour body clock that plays a critical role in when we fall asleep and when we wake up.
When it is dark, the body produces more melatonin; when it is light, the production of melatonin drops. Being exposed to bright lights in the evening (such as TVs and computers) or too little light during the day can disrupt the body’s normal melatonin cycles. For example, jet lag, shift work, summertime — especially for those living in very northern latitudes — and poor vision can all disrupt melatonin cycles.
Melatonin helps control the timing and release of female reproductive hormones and therefore affects all aspects of the menstrual cycle. Researchers have found that melatonin levels tend to decrease with age. One study of 334 people aged 55 and older found that sustained-release melatonin seemed to help people fall asleep faster, sleep better, be more alert in the morning, and improve quality of life in people with primary insomnia. Melatonin may help elderly people with insomnia who are tapering off or stopping benzodiazepines such as lorazepam (Ativan). You should never combine melatonin with sedative medications without medical supervision.
Women with breast cancer tend to have lower levels of melatonin than those without the disease. Laboratory experiments have found that low levels of melatonin stimulate the growth of certain types of breast cancer cells, while adding melatonin to these cells slows their growth. In a study that included a small number of women with breast cancer, melatonin (given seven days before beginning chemotherapy) prevented the lowering of platelets in the blood — a common complication that can lead to bleeding.
In another small study of women who were taking tamoxifen for breast cancer but seeing no improvement, adding melatonin caused tumours to modestly shrink in more than 28 per cent of the women. Men with prostate cancer also have lower melatonin levels than men without the disease. In one small-scale study, melatonin combined with conventional medical treatment improved survival rates in nine out of 14 men with metastatic prostate cancer. People with cancer should talk to their ND and their oncologist before taking medication. Melatonin is also an effective adjuvant treatment in non-small cell lung cancer as well as a preventative agent in lung cancer recurrence.
Melatonin may improve the effect of certain medications but interfere with the effectiveness of others and is contraindicated in pregnant and lactating women, so if this is you then you should not supplement with melatonin before consulting an ND, MD or pharmacist or before giving it to a child.
Some people may have vivid dreams or nightmares when they take melatonin. Taking too much melatonin may disrupt circadian rhythms.
Melatonin is available as tablets, capsules, and lozenges that dissolve under the tongue. You should only use the lowest amount possible to achieve the desired effect and if it causes daytime drowsiness you should decrease the dose. For jet lag or shift work, take melatonin one hour before bedtime as needed.
Kali Simmonds, ND is a doctor of naturopathic medicine who practices in Charlottetown. The information provided is not intended to diagnose or substitute the advice of your healthcare professional. Consult with your health-care provider before making any changes. She welcomes questions for this column, which is published every second Tuesday in The Guardian. She can be reached by mail at 34 Queen St., Charlottetown, C1A 4A3 or by email at firstname.lastname@example.org.