You can be almost certain that if the US is accusing our enemies of doing something, we are doing it ourselves.
Performance Enhancing Drugs (PEDs) are standard issue for special forces. Even pilots get uppers and downers for increased focus, and the ability to sleep afterwards. Nobody cares if soldiers and Marines are using steroids.
Looking at it pragmatically, if I were in a position where my life were literally on the line, I would want every advantage I could get.