Most bodybuilders are familiar with anabolic drugs—testosterone, growth hormone, insulin, and anabolic steroids—that help build muscle mass. The widespread use of these substances in professional bodybuilding demonstrates their effectiveness, though their results depend heavily on individual genetics, training, and nutrition.
What's less commonly discussed are the prescription medications that do the opposite: drugs that promote muscle loss. These catabolic medications can significantly undermine muscle-building efforts, yet many athletes and fitness enthusiasts take them without realizing the impact on their physique goals.
While the effects of various anabolic drugs are well-known, drugs that work oppositely, that is, drugs that promote a loss of muscle mass, are far less known. Such knowledge is essential because it affects bodybuilding progress. Because you know the impact of a particular drug on muscle, you can take steps to overcome the possible catabolic effects of the drug. Certain drugs are necessary to treat various illnesses, but they can also block muscle-building progress as an unwanted side effect. An excellent recent example of this is the popular GLP-1 agonist drugs, such as Ozempic and others. These drugs are analogs of the natural gastrointestinal hormone glucagon-like peptide-1 (GLP-1).GLP-1 functions to work with insulin to control blood glucose levels. GL-1 agonist drugs were initially used to treat diabetes. But an unexpected side effect was weight loss. Ozempic and other GLP-1 agonist drugs promote weight loss by two mechanisms. The first is that they slow the passage of food through the intestinal tract, which produces a feeling of fullness that leads to a lower total daily calorie intake. The second mechanism involves interactions with a fat cell protein called leptin that signals to the brain that fat cells are replete with stored fat. That signal is picked up by appetite-control centers in the hypothalamus, resulting in a significantly reduced appetite. The net effect of these GLP-1 agonist activities is less food intake and significant weight loss.
The efficacy of GLP-1 agonist drugs was such that drug companies repackaged some of them as weight-loss drugs. However, while GLP-1 agonists come with possible side effects, mainly related to gastrointestinal problems such as intestinal obstruction, the considerable weight loss induced by the drugs can consist of as much as 40% muscle mass. Losing muscle mass after a weight-loss diet is undesirable because it reduces resting metabolic rate. In short, with extensive muscle loss from dieting, you burn fewer calories, making it likely to regain the lost weight. That explains the 95% recidivism rate of most diets. The best way to maintain weight loss, hopefully . . .
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