Phentermine is a prescription weight‑loss medication. It’s a stimulant that acts on the central nervous system to help suppress appetite.
Key points:
- Use: For adults who are overweight or have obesity, typically for a short term (often a few weeks to a few months) as part of a weight‑loss plan that includes diet and exercise. It’s usually considered when BMI is 30 or higher, or 27+ with weight‑related health issues.
- How it works: Increases certain chemicals in the brain (notably norepinephrine) to reduce appetite. It is not a fat burner.
- Form and dosing: Available in several immediate‑release forms (commonly 8 mg, 15 mg, or 37.5 mg tablets). Dosing is usually taken once daily in the morning to avoid sleep problems; some regimens involve split doses, depending on the product.
- Duration and guidance: Generally intended for short-term use. Doctors often reassess after a few weeks. If there isn’t meaningful weight loss or if side effects are troublesome, it may be stopped.
- Who should not take it: Pregnancy, uncontrolled high blood pressure or heart disease, glaucoma, hyperthyroidism, a history of certain substance use disorders, or use with monoamine oxidase inhibitors (MAOIs) or other stimulants.
- Side effects: Common ones include insomnia, dry mouth, increased heart rate or blood pressure, nervousness, dizziness, and constipation. Serious side effects require immediate medical attention.
- Safety notes: It is a controlled substance (Schedule IV) due to potential for abuse and dependence. It should be used under a clinician’s supervision, and you should avoid other stimulants (e.g., certain decongestants, caffeine) in excess while taking it.
- Monitoring: Blood pressure and heart rate, weight loss progress, and any new or worsening symptoms should be checked by your healthcare provider.
If you’re considering phentermine or have questions about whether it’s right for you, talk with a healthcare professional who can review your health history and current medications. If you want, I can help list questions to ask your doctor or explain any specific side effects you’re worried about.