Many fibromyalgic patients have sleep disorders. Researchers found that when subjects attempted to enter deep sleep, higher-frequency alpha wave activity intruded, disrupting the normal and necessary periods of delta-wave sleep. Further, when subjects who did NOT have FMS spent several consecutive nights in a controlled sleep environment where noise was generated to disrupt delta-wave sleep, the individuals developed symptoms of FMS. This unrefreshing sleep could be caused by abnormalities in growth hormone. About 30% of fibromyalgic patients have low levels of insulin-like growth factor, another indicator of reduced growth hormone secretion.

Growth hormone is been studied to treat FMS but needs very expensive IM injections.