Phentermine: Side Effects, Uses & Monitoring
Phentermine hydrochloride capsules are indicated as a short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous ob
- Data source
- FDA labeling via NIH DailyMed (label 1c0195e8…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
No structured frequency data available in current labeling. Consult the official label.
Labeled uses (from FDA prescribing information)
Phentermine hydrochloride capsules are indicated as a short-term (a few weeks) adjunct in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index ≥ 30 kg/m2 , or ≥ 27 kg/m2 in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia). Below is a chart of body mass index (BMI) based on various heights and weights. BMI is calculated by taking the patient’s weight, in kilograms (kg), divided by the patient’s height, in meters (m), squared. Metric conversions are as follows: pounds ÷ 2.2 = kg; inches x 0.0254 = meters. BODY MASS INDEX (BMI), kg/m2 | Height (feet, inches) | Weight (pounds) | 5'0" | 5'3" | 5'6" | 5'9" | 6'0" | 6'3" | 140 | 27 | 25 | 23 | 21 | 19 | 18 | 150 | 29 | 27 | 24 | 22 | 20 | 19 | 160 | 31 | 28 | 26 | 24 | 22 | 20 | 170 | 33 | 30 | 28 | 25 | 23 | 21 | 180 | 35 | 32 | 29 | 27 | 25 | 23 | 190 | 37 | 34 | 31 | 28 | 26 | 24 | 200 | 39 | 36 | 32 | 30 | 27 | 25 | 210 | 41 | 37 | 34 | 31 | 29 | 26 | 220 | 43 | 39 | 36 | 33 | 30 | 28 | 230 | 45 | 41…
Conditions associated with Phentermine in labeling
Hyperlipidemia
Elevated levels of cholesterol or triglycerides in the blood, a major risk factor for heart attack and stroke....
Hypertension
Chronically elevated blood pressure that puts strain on the heart, blood vessels, kidneys, and brain. Often ha...
Obesity
A complex disease involving excessive body fat that increases the risk of many other health conditions....
Frequently Asked Questions
What is Phentermine used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Phentermine?
Current labeling for this ingredient does not include a structured frequency table that we can reproduce. Review the official label linked below.
Does Phentermine require lab monitoring?
Monitoring needs vary. Ask your healthcare provider whether any lab tests apply while taking Phentermine.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.