What does “off-label” mean for an oral weight-loss prescription?

Off-label means an approved medicine is prescribed outside its FDA-approved labeling, such as for a different purpose or duration. This is common across medicine and is not automatically experimental. It does require a sound clinical reason and appropriate monitoring. FDA explanation.

Phentermine alone retains short-term labeling. Qsymia combines phentermine and topiramate and is approved for long-term weight management. That demonstrates an approved long-term use of the combination; it does not establish FDA approval for long-term phentermine alone or every separately prescribed combination. Qsymia prescribing information.

Next: Ask why the proposed use fits your situation and how it will be monitored.