We got the "Botched" star outside Craig's Thursday ... and he doubles down on his initial claims against her ... practically shouting from the rooftops this time that her career as a personal trainer doesn't permit her to dish out medical advice.

Despite publicly discrediting her PT career yet again, he appears to extend an olive branch ... saying she's actually great at her job -- but it's a back-handed compliment ... 'cause he says she still doesn't have medical validation to influence others against weight loss drugs.

Now, Terry does offer her a solution if she feels an absolute need to continue doing so -- Take her MCAT and go to med school. Savage!

He also says the article Jillian cited in which he appeared to agree with her anti-Ozempic stance was taken out of context and doesn't hold up her argument -- explaining he was only being interviewed about the dangers of Ozempic ... hence why he was discussing it's side effects.

That's not all ... TD also ain't here for Jillian's claims she's the utmost authority on weight loss ... suggesting if that was the case, then she'd already be aware that diet and exercise alone doesn't cut it when tackling the obesity problem.

He says bottom line, any medication can be dangerous, but drugs like Ozempic are saving lives -- so Jillian needs to mind her own business and leave the advice to those with qualifications.

For good measure, the doc's wife, Heather Dubrow, jumps in ... saying she's known him for 30 years and he never changes his mind on anything -- an apparent shot at JM to back down and accept defeat.