SAMe

What Is SAMe?

SAMe is S-adenosyl-L-methionine, a molecule your cells build from the amino acid methionine and ATP. The liver makes the most of it. The free molecule is chemically fragile, so it is supplied here as the disulfate tosylate salt, at 200 mg per serving.

How It Works in the Body

SAMe carries a methyl group, one carbon and three hydrogens, on a positively charged sulfur atom. That charge leaves the methyl loosely held and easy to hand over. Dozens of enzymes take it: they methylate DNA, the phospholipids of cell membranes, and several neurotransmitters. What remains once the methyl goes is returned to methionine with help from folate and vitamin B12, or sent down the sulfur route toward cysteine. A decarboxylated form of SAMe feeds polyamine synthesis instead.

What It Supports

• Methylation reactions: SAMe is the body's main methyl donor, so it is involved in chemistry right across the cell.
• Nervous system chemistry: The enzymes that finish several neurotransmitters take their methyl group from SAMe.
• Sulfur supply: What is left after the methyl is handed off can travel on to cysteine, the building block of glutathione.
• Cell membranes: Phosphatidylcholine is made by methylating phosphatidylethanolamine three times over, with SAMe supplying each methyl.

Who It May Suit

People who would rather supply the methyl donor itself than the vitamins that regenerate it, folate, B12 and B6 among them. A serving is one capsule. The capsule is plant cellulose and the stearate comes from a vegetable source, so it fits vegetarian and vegan eating.

Good To Know

SAMe always comes as a stabilized salt, because the free molecule does not keep its shape. Talk with your healthcare provider before use if you take an antidepressant, a triptan or anything else acting on serotonin, since SAMe can add to that effect; if you have bipolar disorder, where SAMe has been linked to manic episodes; or if you take levodopa, which SAMe can methylate.