Source Naturals SAMe is a stable, bioavailable form of S-adenosyl-L-methionine. These tablets are enteric coated and blister packed to prevent breakdown and inactivation of the ingredients. Dozens of clinical studies have demonstrated that SAMe supports joint comfort, function and mobility in the spine, hips and knees. It is important to the joints because of its critical role in cartilage formation. Studies also show that SAMe helps support a positive outlook. It is able to cross the blood-brain barrier where it affects the synthesis and activation of various proteins, such as neurotransmitters. SAMe is known as a "methyl donor." This means that it works by giving up a piece of itself (a methyl group consisting of one carbon and three hydrogen atoms) to other molecules. Methylation plays a part in many critical cellular functions. SAMe is present in every living cell in the body. However, levels of SAMe tend to decline with age.