Consent is a separate issue. Medical ethics make it unethical to do something good for society but with no benefit to the patient, even with the consent of t

Consent is a separate issue. Medical ethics make it unethical to do something good for society but with no benefit to the patient, even with the consent of the patient. Note that there are a few cases where these medical ethics are violated for historic reasons. For example, donating a kidney (no benefit to the donor). Another example: Taking a vaccine for an almost eradicated disease (at that point, you are taking the vaccine for the social purpose of eradicating the disease, not for the personal benefit of not contracting the disease). These things are grandfathered into medical ethics, but would no longer be allowed if proposed today.