Short answer: The usual adult phendimetrazine dose is one 35 mg tablet twice a day or three times a day, one hour before meals. The dose is set to the lowest that works, and in some cases half a tablet (17.5 mg) per dose may be enough. It should not exceed 2 tablets three times a day. It is for short-term use of a few weeks. The label gives no missed-dose instruction.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Phendimetrazine is approved for: Phendimetrazine is approved as a short-term (a few weeks) add-on to a calorie-restricted weight-loss plan for obesity in people with a starting BMI of 30 kg/m2 or more who have not responded to diet and/or exercise alone, and only on its own, not with other weight-loss drugs (Indications and Usage). The package label prints CIII, and the label calls it a controlled substance (Drug Abuse and Dependence).
Source
Phendimetrazine Tartrate Tablets, USP, 35 mg, CIII, prescribing information. Preferred Pharmaceuticals (repackager). DailyMed, version published August 17, 2026. DailyMed setid 767b5386-1e56-4eeb-8d59-510b940ab75e
Phendimetrazine 35 mg is a tablet taken by mouth, one tablet two or three times a day, one hour before meals (Dosage and Administration).
The dose is individualized to the lowest effective dosage; half a tablet (17.5 mg) per dose may be adequate in some cases (Dosage and Administration).
It is a short-term add-on of a few weeks to a calorie-restricted weight-loss plan (Indications and Usage).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Item | Dose |
|---|---|
| Usual adult dosage | 1 tablet (35 mg) twice a day or three times a day one hour before meals |
| Lower dose in some cases | ½ tablet (17.5 mg) per dose |
| Maximum | Should not exceed 2 tablets three times a day |
Treatment continues only if there is satisfactory weight loss within the first 4 weeks, for example at least 4 pounds, or as decided by the physician and patient.
When tolerance develops, use is stopped and the maximum recommended dose is not exceeded.
The least amount feasible is prescribed or dispensed at one time to reduce the chance of overdose.
Tablets are stored at 20 to 25 C (68 to 77 F), with excursions from 15 to 30 C allowed.
The phendimetrazine label gives no missed-dose instruction. Ask your prescriber or pharmacist what to do if a dose is missed.
In Dose Track you set up Phendimetrazine as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.