SARMs are similar to AAS, but they are not one and the same. Both work by binding to your androgen receptors, triggering changes in your DNA which increase your muscles’ ability to grow. But steroids can also impact other parts of the body, leading to side effects such as prostate issues, hair loss and acne. SARMs, however, are said to be "tissue selective" – they target your muscles without setting off this same chain of reactions. They're also taken in pill form, rather than injected.