The FDA’s Office of Prescription Drug Promotion sent a warning letter to Galt Pharmaceuticals for intentionally sending an email to doctors about its insomnia pill Doral (quazepam) that failed to mention that the drug is a benzodiazepine, a class-four controlled substance.

The company’s email included numerous claims and presentations about the benefits of Doral, but it omitted “material information,” the agency said.

Galt claimed that Doral’s likelihood of abuse is considerably lower than widely used sleep-aids, and said it was ranked lower than over-the-counter diphenhydramine for relative abuse potential. The email also compared the “relative likelihood of abuse” of 19 drugs, with Doral’s active ingredient scoring lower than 16 of the drugs.