What is phentermine?
Phentermine is a sympathomimetic amine, a stimulant related to amphetamine. It is a Schedule IV controlled substance in the U.S.
What is phentermine used for?
Obesity in adults with a high BMI, especially when weight-related conditions like high blood pressure or type 2 diabetes are present.
How does phentermine work?
It increases norepinephrine in the brain, which reduces hunger.
How should you take phentermine?
Usually once daily in the morning, as prescribed. Extended-release (ER) versions release the medicine slowly through the day.
What are the common side effects of phentermine?
- Dry mouth
- Insomnia
- Restlessness
- Fast heartbeat
- Constipation
What are the serious risks of phentermine?
- High blood pressure and heart problems
- Pulmonary hypertension, which is rare but serious
- Dependence
- It isn’t recommended for people with heart disease, an overactive thyroid, glaucoma or a history of substance misuse.
Frequently asked questions
How long can you take phentermine?
It’s typically approved for short-term use of a few weeks. Your prescriber decides what’s appropriate for you.
Is phentermine the same as Adderall?
No. They’re related stimulants, but they’re used for different conditions.
The bottom line
Phentermine can help some adults jump-start weight loss, but it’s a short-term tool that needs medical monitoring.