Some people may be allergic to s-adenosylmethionine, and signs of an allergic reaction include difficulty breathing, itching, rash and hives, according to Drugs.com. Other symptoms associated with an allergic reaction to the supplement include tightness in the chest and swelling of the tongue, face, lips or mouth. It may cause unusual irritability, hyperactivity, drastic mood changes or shifts in behavior.
People with a history of bipolar disorder should not use s-adenosylmethionine, cautions Drugs.com. Because it may interact with some medical conditions, it is important to speak to a health care provider before using it. The compound may cause nausea or a mild upset stomach.
Women who are pregnant, planning on becoming pregnant or nursing should speak to a physician or pharmacist before using s-adenosylmethionine, states Drugs.com, and it may interact with herbal preparations, dietary supplements and over-the-counter or prescription medicines, although no definite interactions are known, as of 2015.
S-adenosylmethionine may cause sleeping problems, so it should not be taken at night, recommends Drugs.com. Unless otherwise instructed by a health care provider, only use it as instructed on the package. If symptoms of depression continue or increase, speak to a doctor. Children should not use the supplement. The long-term safety of s-adenosylmethionine is unknown.