MGA is frequently used as an appetite stimulant to promote weight gain. The direct mechanism of appetite enhancement is unclear, but it is known that MGA induces a variety of downstream changes to cause the effect, including stimulation of the release of neuropeptide Y in the hypothalamus, neurosteroid-like modulation of calcium channels in the ventromedial hypothalamus, and inhibition of the secretion of proinflammatory cytokines including interleukin 1α, interleukin 1β, interleukin 6, and tumor necrosis factor α, all of which have been implicated in facilitation of appetite. Increased levels of insulin-like growth factor 1 (IGF-1) may also be involved, specifically in its anabolic effects. Studies of MGA in elderly patients who experience weight loss are limited and of poor quality with most showing minimal or no weight gain, with no nutritional or clinically significant beneficial outcomes observed. In patients who take MGA, one in 12 will have an increase in weight.