I mean how safe
YK-11 is not worth the trouble imo. It is liver toxic due to it being a steroid actually. I did not see any rats having exceptional gains on this compound other than LGD or RAD. So how safe is YK-11? Not so safe as sarms (YK-11 is not a specific sarm also)
We don't know that much about YK-11 yet. So how safe it is, no clue. If it's worth taking or not, i've no idea since I've never used it myself. But my friend is currently running his rat on it and he is very satisfied with the results so far.