Bioavailability and Lack of Toxicity of S‐Adenosyl‐l‐Methionine (SAMe) in Humans

Abstract

Oral dosages of 1600 mg/day of SAMe appear to be significantly bioavailable and nontoxic, at least regarding toxic methylated metabolites and homocysteine. However, the risk of mania in vulnerable individuals remains a serious concern.

S-adenosylmethionine and betaine correct hepatitis C virus induced inhibition of interferon signalingin vitro

“…In another study, steady state serum concentrations after multiple oral doses (2 ϫ 800 mg/d) over 4 weeks were 790 nmol/L. 54 AdoMet and betaine are both nontoxic substances that are available in many countries without prescription, and it might be tempting to add them to the current standard therapy with pegIFN␣ and ribavirin. However, we would advise to use these substances only in the context of well-designed clinical studies.…”

Alternative Treatments in Pediatric Bipolar Disorder

“…111,112 As it is a dietary supplement, SAMe has not undergone the rigorous safety testing required for prescription drugs, and although short-term trials have suggested that SAMe is safe, no long-term data exist. 111 Potential adverse effects include gastrointestinal side effects (primarily flatulence and diarrhea), headache, dizziness, dry mouth, nausea, and cold or flu-like symptoms. 111 In addition, mild nausea, restlessness, and moderate increase in anxiety have been observed in some patients.…”

“…111 Potential adverse effects include gastrointestinal side effects (primarily flatulence and diarrhea), headache, dizziness, dry mouth, nausea, and cold or flu-like symptoms. 111 In addition, mild nausea, restlessness, and moderate increase in anxiety have been observed in some patients. 107 SAMe should be avoided in patients with personal or family history of bipolar disorder unless patients are also taking a mood stabilizer, as there are several reports of SAMe-induced mania.…”

“…107 SAMe should be avoided in patients with personal or family history of bipolar disorder unless patients are also taking a mood stabilizer, as there are several reports of SAMe-induced mania. 111,113 In addition, Iruela and colleagues 114 published a case report describing altered mentation, fever, hyperreflexia, and elevated Cr phosphokinase when SAMe (100 mg intramuscular) was combined with clomipramine 75 mg in a 71-year-old woman. Similar symptoms suggesting serotonin syndrome have not been described in controlled studies evaluating the efficacy and safety of SAMe administered in conjugation with older antidepressants.…”

Role of S-Adenosylmethionine (SAMe) in the Treatment of Osteoarthritis

“…Oral dosages of 1600 mg/day of SAMe appear to be significantly bioavailable and nontoxic. 13 As many as 29% to 46% of patients with major depressive disorder (MDD) show only partial or no response to an adequate course of an antidepressant. The current practice is to increase the dose, switch to another antidepressant, or to combine the initial antidepressant with an antidepressant of a different class or a nonantidepressant agent.…”