May 2013

Melatonin and Poor Sleep Linked in Polycystic Ovary Syndrome

Lower levels of melatonin may be linked to significantly reduced sleep quality in women who have polycystic ovary syndrome (PCOS), a study reports.

PCOS is an endocrine disorder that affects approximately 5-10 percent of women of childbearing age. It is a leading cause of infertility and occurs among all races and nationalities. It is the most common hormonal disorder among women of reproductive age.

Melatonin is a hormone that is made by the pineal gland. The synthesis and release of melatonin are stimulated by darkness and suppressed by light, suggesting that melatonin may be involved in circadian rhythm and the regulation of many body functions. Levels of melatonin in the blood are highest before bedtime. Synthetic melatonin supplements have been used for a variety of medical conditions, most notably for disorders related to sleep.

Previous studies suggest that women with PCOS may experience sleep problems. In the current study, researchers looked at the link between sleep quality and levels of melatonin, as well as levels of a marker of oxidative stress called 8-hydroxydeoxyguanosine (8-OHdG). The team evaluated 26 women with PCOS and 26 control subjects, who completed sleep questionnaires for one month. Urine samples were collected at various time points, and the participants' sleep patterns and lighting environment were monitored for three days and nights.

The results showed that women with PCOS had significantly high levels of melatonin and 8-OHdG in their urine at night, compared to controls. They also had significantly reduced sleep quality.

The researchers concluded that high nighttime melatonin and 8-OHdG levels may be linked to poor sleep quality in women who have PCOS. However, they emphasized that the study had a small sample size. Further research is needed before firm conclusions may be made.

Symptoms of PCOS include weight problems, lack of regular ovulation and/or menstruation, skin changes, small ovarian cysts, trouble getting pregnant, and excessive amounts or effects of androgenic (masculinizing) hormones. The symptoms and severity of the syndrome tend to start gradually and vary greatly among women. Women are usually diagnosed when in their 20s or 30s, but PCOS may also affect teenage girls. In these girls, the symptoms often begin after the first menstrual cycle. It is common for PCOS symptoms to be mistaken for other medical problems. Symptoms may be especially noticeable after a weight gain. PCOS cannot be prevented. However, early diagnosis and treatment may help in the prevention of long-term complications, such as endometrial cancer, infertility, diabetes, high blood pressure, and heart disease.

Chromium has been studied for the treatment of PCOS symptoms and is supported by good scientific evidence. Arginine, dodder, licorice, and motherwort have also been evaluated for this condition, but there is unclear or conflicting evidence on their effectiveness. More research is needed.

For more information about PCOS, please visit Natural Standard's Medical Conditions Database.


  1. Natural Standard: The Authority on Integrative Medicine. 
  2. Shreeve N, Cagampang F, Sadek K, et al. Poor sleep in PCOS; is melatonin the culprit? Hum Reprod. 2013 May;28(5):1348-53. doi: 10.1093/humrep/det013. Epub 2013 Feb 24.

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