The Centers for Disease Control and Prevention released data that shows just how many folks are taking prescription sleep-inducing medications.

The findings: more women than men resort to using sleep aids. Also, the higher the education level, the more likely consumers are to seek out pharmacological assistance to get to sleep.

The study found that sleeplessness is not a clear math problem. While seven hours of sleep is considered the benchmark, the CDC found that the people buying and using sleep aids is generally comprised of people who get five hours or less, or more than eight hours a night.

Despite demand, the sleep market has been proven a hard one to dominate. Sanofi’s Ambien (zolpidem), for example, has been associated with sleepwalking, as well as eating and driving while asleep. The FDA recently required zolpidem manufacturers to reduce the dosage in already-available products because of what can be considered a hangover effect that meant zolpidem users woke up feeling alert, yet impaired because high levels of the drug were still circulating.

Transcept/Purdue Pharma’s Intermezzo honed in on a subcategory of sleeplessness—patients who can’t stay asleep. But that niche approach, apparently, was not enough for commercial success, and the companies reduced the product’s  DTC promotion as of May.

Category competition includes Sunovion’s Lunesta (eszopiclone) and Takeda’s Rozerem (ramelteon). Transcept’s first quarter report also notes that off-label competition of sleep drugs like Pfizer’s shorter-acting Sonata (zaleplon) and Pernix’s Silenor (doxepin), as well as the antidepressant trazodone, answer that same short-term consumer need.

At the same time, sleep has also become linked to the obesity epidemic. Nature Communications published a study in July linking sleep deprivation with brain activity that triggers “a significant increase in the desire for weight-gain promoting high-calorie foods.” The study’s author Matthew Walker told the New York Times that the sleep/food link works two ways: the brain not only makes the sleepless desire calorie-dense foods, but also weakens the person’s ability to refuse them. A 2007 study published by Medscape Neurology noted that too little sleep could be linked to insulin resistance, which is a risk factor for diabetes and obesity. This same study also found that chronic sleeplessness, or in this case, six days of less than four hours of sleep, led to a lower release of the hormone leptin, which signals satiety. The impact was so great that the lower level was the same as if the patients cut their caloric intake by 900 calories for three days.