Informed consent, a patient's yes, on the record.

Consent is an explanation the provider gives and documents; a signature alone does not replace it. For telehealth, many states also require consent to receive care by telehealth, sometimes with set disclosures about how the visit works, privacy, and what to do in an emergency.

Some treatments carry extra disclosures. Compounded drugs are not FDA-approved, off-label uses have to be explained, and some medications come with specific risk warnings. Consent to treatment is also separate from marketing consent: permission to send text messages falls under telecommunications law and needs its own opt-in.