Melatonin P.R. tablets, provided by Douglas Laboratories, contain 3 mg of purest pharmaceutical grade melatonin, in a prolonged-release, bisected tablet. Each Tablet Contains:Melatonin 3 mg Suggested Use:Adults take 1 tablet 1 hour before bedtime as directed by physician only. Side Effects:Not to be taken by individuals under the age of 18. If you are pregnant, nursing, taking any prescription medication (especially hormone replacement therapy), or have an autoimmune or depressive disorder consult a physician before using this product. Long-term use of melatonin has not been studied. Use of this product could cause hypothermia. Do not use before or while operating a motor vehicle or heavy machinery.