Phentermine
Adipex-PPubChem CID 4771 · 3D model
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A stimulant-like appetite suppressant, chemically related to amphetamine, that revs up the brain's norepinephrine signaling to dull hunger — a much older, short-term-only approach compared to newer GLP-1 drugs like semaglutide.
How it works
Phentermine works more like a stimulant than like the newer weight-loss drugs. It's chemically related to amphetamine, and it's believed to work by pushing the brain's 'fight-or-flight' chemical, norepinephrine, out around nerve endings in an appetite-control region of the brain. That's a completely different route than drugs like semaglutide and orforglipron, also on this site, which instead lock onto the same receptor as the body's natural fullness hormone, GLP-1, to slow digestion and signal 'you're full.'
What it’s used for
Adipex-P is approved only as a short-term boost, a few weeks at most, alongside diet, exercise, and behavior changes, for adults with obesity or excess weight plus a related health risk like high blood pressure or diabetes. That's very different from newer drugs like semaglutide and orforglipron, also on this site, which are meant to be taken long-term.
- Mechanism
- Sympathomimetic amine (amphetamine-related stimulant); appetite suppressant
- Drug class
- Small molecule
- Therapeutic area
- Metabolic / Weight Management