I don't think giving someone "medical advice" in the US requires a license per se; legal entities use "this is not medical advice" type disclaimers just to avoid liability.
What’s illegal is practicing medicine. Giving medical advice can be “practicing medicine” depending on how specific it is and whether a reasonable person receiving the advice thinks you have medical training.
Disclaimers like “I am not a doctor and this is not medical advice” aren’t just for avoiding civil liability, they’re to make it clear that you aren’t representing yourself as a doctor.
