accutane cleared my cystic acne, so now im using anti-biotics to treat mild acne, can I use the dermaroller whilst on anti-biotics? (tetracycline)

I dont see why not.

You shouldnt use it while you have any active acne, not even mild acne. When your skin is clear, feel free. Pimples are mini infections, if you dermaroll over them and go over the rest of your face youre literally introducing infection to every pin prick the dermaroller makes in your skin. Not a great idea.

I've used it while on antibiotics. Didn't damage my skin at all.