If you experience any gastrointestinal discomfort or gastrointestinal side effects, discontinue use and consult a physician. Consult a physician if sleeplessness persists continuously for more than 3 weeks. Consult a physician if symptoms persist or worsen. Consult a physician prior to use if you are pregnant or breastfeeding. Consult a physician prior to use if you are taking carbidopa or drugs/supplements with serotonergic activity. These may include, but are not limited to L-tryptophan, S-adenosylmethionine (SAMe), St. John's wort, antidepressants, pain killers, over the counter cough and cold medication containing dextromethorphan, anti-nausea medication and anti-migraine medication. Discontinue use and consult a physician if you show signs of weakness, oral ulcers, or abdominal pain accompanied by severe muscle pain or if you experience skin changes. Do not use if you have scleroderma. Some people may experience drowsiness. Exercise caution if operating heavy machinery, driving a motor vehicle or involved in activities requiring mental alertness. Some people may experience diarrhea, nausea, vomiting and abdominal pain. Keep out of reach of children.