Your step-up schedule
Qsymia does not step up on a fixed timetable. After the first 14 days, the label ties each further increase to how much weight has come off.
- Days 1–143.75/23mg
The starting dose, taken once each morning. The label says to avoid taking Qsymia in the evening because of the possibility of insomnia.
- Day 15 onwards7.5/46mg
The recommended dose after the first 14 days. Many people stay here.
- Only if 3% not lost by week 1211.25/69mg
A 14-day bridging dose. The label steps up only if an adult has not lost at least 3% of starting body weight on 7.5 mg/46 mg.
- 14 days later15/92mg
The highest strength. After 12 weeks on it, the label says to stop Qsymia if an adult has not lost at least 5% of starting body weight.
Maximum dose
This is the schedule in Dosage and Administration (2.2) of the FDA label. Stopping the 15 mg/92 mg dose is not immediate: the label says to take it every other day for at least one week first, because stopping abruptly can bring on a seizure.
Starting dose vs maximum dose
The maximum dose is the highest approved dose — it is not the same as your maintenance dose.
Starting dose
3.75/23mg
Maximum dose
15/92mg
Not everyone moves past 7.5 mg/46 mg. The FDA label only calls for a step up to the higher strengths if an adult has not lost at least 3% of their starting body weight after 12 weeks on 7.5 mg/46 mg.
Weight loss at each dose
The label does not report weight loss by dose for Qsymia, so there is no dose-by-dose breakdown to show here. See what the trials found at the full dose →
When your doctor might change your dose
Your dosing is flexible and tailored to your needs.
Losing weight on 7.5/46 mg
The label only calls for a step up if 3% of starting weight has not gone by week 12.
Reduced kidney or liver function
The label caps the dose at 7.5 mg/46 mg in moderate or severe renal impairment and in moderate hepatic impairment.
Coming off the top dose
The label tapers 15 mg/92 mg to every other day for at least a week before stopping.
Common questions
Written and maintained by one person · Built with agentic AI tools · Every number checked against the cited trial · Not medical advice
- Qsymia (phentermine and topiramate) prescribing information — Dosage and Administration (2.1, 2.2, 2.3, 2.4, 2.5), Medication Guide View source ↗
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