Phentermine is a sympathomimetic anorectic agent used as a short-term adjunct therapy that is included in a regimen of weight reduction in cases of exogenous obesity. Phentermine is a sympathomimetic amine anorectic agent and it was introduced in 1959 as part of an anti-obesity combination drug.
- Mechanism
- Curator reviewed · 5 references
Phentermine is an indirect-acting sympathomimetic agent that acts by releasing noradrenaline from the presynaptic vesicles in the lateral hypothalamus. This increase in noradrenaline concentration in the synaptic cleft results in the stimulation of beta2-adrenergic receptors. Phentermine is classified as an indirect sympathomimetic due to the increase in the level of norepinephrine, dopamine and its indirect effect towards serotonin. Some reports have indicated that phentermine inhibits the neuropeptide Y which is a principal signaling pathway for the induction of hunger. This combined effect produces a continuous flight-or-fight response in the body which reduces the hunger signal as this state is on the immediate need for energy.
Lastly, some reports have indicated that phentermine is a weak inhibitor of monoamine oxidase but this mechanism does not tend to produce a clinically significant response.
- Primary indication
- Phentermine is indicated, alone or in combination with topiramate, as a short-term adjunct, not pass a few weeks, in a regimen of weight reduction based on exercise, behavioral modifications and caloric restriction in the management...Curator reviewed · 5 structured indications
- Formula / weight
- C10H15N · 149.2328 g/mol (avg)
- First approval
- Canada, 2006 · United States, 1959
- Also known as
- Phentermine resin
- Brand names
Resolves to
DHHVAGZRUROJKS-UHFFFAOYSA-NSMILESCC(C)(N)CC1=CC=CC=C1What you can answer from here — as of September 23, 2026
Which drugs share a target with Phentermine, and which of those have an active Phase 3 trial?
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