Skip to main content

Phendimetrazine Dosage

Medically reviewed by Last updated on Jul 22, 2022.

Applies to the following strengths: 35 mg; 105 mg

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Obesity

Extended-release: 105 mg orally once a day, 30 to 60 minutes before morning meal

Immediate-release: 35 mg orally 2 or 3 times a day, one hour before meals

  • Dosage should be individualized to obtain an adequate response with the lowest effective dose; for some patients, 17.5 mg per dose may be adequate
Maximum dose: 70 mg orally 3 times a day, one hour before meals

  • For use as monotherapy only; indicated for short term use, e.g. a few weeks.

Uses: Management of exogenous obesity as a short-term adjunct in a regimen of weight reduction based on caloric restriction in patients with:
  • an initial BMI of 30 kg/m2 or greater OR
  • an initial BMI of 27 kg/m2 or greater in the presence of other risk factors (e.g., hypertension, diabetes, hyperlipidemia) who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone.

Usual Pediatric Dose for Obesity

Extended-release (17 years and older): See Adult Dose

Renal Dose Adjustments

Data not available; Use with caution.

Liver Dose Adjustments

Data not available

Dose Adjustments

Elderly: Dose selection should be cautious

When Tolerance to Anorectic Effect Develops (usually occurs within a few weeks):

  • Discontinue treatment; maximum recommended dose should not be exceeded.


Extended-release: Safety and efficacy have not been established in patients younger than 17 years.

Immediate-release: Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

US Controlled Substance: Schedule III


Data not available

Other Comments

Administration Advice:

  • Immediate-release tablet: Take orally 2 or 3 times a day 1 hour before meals
  • Extended-release capsules: Take orally 30 to 60 minutes before morning meal

  • This drug should be used as monotherapy; efficacy with other anorectic agents has not been studied and the combine use may have the potential for serious cardiac problems.

Patient Advice:
  • Patients should be instructed to read the patient labeling.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.