Consult a health care practitioner if sleeplessness persists for more than 4 weeks (chronic insomnia). Do not use this product if you are pregnant or breastfeeding. Avoid taking with alcohol or products that cause drowsiness. Consult a health care practitioner prior to use if you are taking medications for seizure, blood pressure, to suppress the immune system (immunosuppressive medications), to affect mental state or increase sedation, steroids or blood thinners. Consult a health care practitioner prior to use if you have cardiovascular, immune, liver or chronic kidney disease, hormonal or seizure disorders, asthma, depression, diabetes, low blood sugar, or migraine. Do not drive or use machinery for 5 hours after taking melatonin. Stop use if allergy occurs or if you experience headache, confusion, or nausea.