SAMe a compound made from methionine, a sulfur-containing amino acid, and adenosine triphosphate (ATP) - the body’s ‘energy’ molecule. SAMe was discovered by an Italian biochemist in 1952, and was first studied as a treatment for depression; during these studies it was found that SAMe also helped to relieve the symptoms of arthritis. At present, SAMe is classed, along with glucosamine and chondroitin, as a potential "chondroprotective" agent, i.e. a substance that not only relieves the symptoms of arthritis but also helps to slow its progression. However, this use of SAMe is yet to be clinically proven. The body usually produces adequate amounts of SAMe, thus there is no dietary requirement. However,  methionine, folate, or vitamin B12 deficiencies can reduce SAMe levels and as it is not found in significant quantities in foods, it must be obtained from a supplement.

Numerous clinical studies have found that SAMe is an effective treatment for osteoarthritis. Some trials have found that SAMe may be useful in the treatment of depression, and certain liver conditions, for example cirrhosis, pregnancy-related jaundice, and Gilbert’s syndrome. Three out of four clinical trials found that SAMe significantly improved the symptoms of fibromyalgia. However, all but one of these trials involved the intravenous or intramuscular injection of SAMe, thus it is unclear if the results would be replicated with oral doses.

DEFICIENCY SYMPTOMS: None known

A typical therapeutic dose of SAMe is 400 mg taken 3-4 times a day.

MAXIMUM SAFE LEVEL: Not established

The most common side effect is mild gastrointestinal upset. People with bipolar disease should avoid SAMe as it can trigger manic episodes. Furthermore, people taking  antidepressants or the anti-Parkinson’s drug levodopa should avoid SAMe unless under medical supervision. People with kidney disease or liver disease should consult their doctor before taking SAMe.