There are non-steroidal OTC supplements that are specifically anti-catabolic instead of anabolic like HMB[1], a metabolite of the amino acid leucine, and also widely used in the fitness community. Personally I have no idea which is preferable though, or whether anti-catabolism is something actually positive, as we know the importance of autophagy of senescent cells for longevity. Most of the literature I read suggests the less growth signalling, the better longevity, with the only exception being the frail elderly.

[1] https://en.wikipedia.org/wiki/%CE%92-Hydroxy_%CE%B2-methylbu...

Most data on HMB shows that it is effective in preserving muscle mass in people with cancer cachexia or the eldery, results are generally not great for those without specific diseases or of younger age.

I'm still taking it because it's cheap and I figure I might as well, but anavar is likely significantly more effective.