How long does Qsymia take to work?
About a month of dose escalation across 3 steps before the dose anyone stays on — quoted from the label, not estimated.
Last updated 2026-04-24 — the version of the FDA label this schedule comes from
How long does it take for Qsymia to work?
Qsymia reaches its maintenance dose no earlier than week 3, because the FDA label steps the dose up on a schedule rather than starting at the dose that does the work. That is about a month of titration before the dose anyone stays on, across 3 steps, and it is the reason an advertised first-month price says so little. The figure people are usually asking about is the 8.6% mean weight loss its label cites, and that came from CONQUER and SEQUEL, phase 3: 6.6% to 8.6% mean weight loss at 56 weeks… Appetite changes are usually reported within the first weeks, but the trial figure is measured over its full length rather than at any earlier point — the two are different claims and are often quoted as one. Every week of that schedule is billed: $98 a month at maintenance on this site, verified against the seller's own page.
The schedule, week by week — and what each week costs
Doses and intervals are quoted from FDA prescribing information for Qsymia (phentermine/topiramate). Prices are the published figure for that dose where the manufacturer prices per step; where it charges one price throughout, the column says so.
| When | Dose | A month at this step | What the label notes |
|---|---|---|---|
| Days 1–14 | 3.75 mg / 23 mg | $98 — one price throughout | Initiation. |
| Day 15 and on | 7.5 mg / 46 mg | $98 — one price throughout | The usual dose. Escalation beyond it depends on weight lost by week 12. |
| Higher steps | 11.25 mg / 69 mg then 15 mg / 92 mg | $98 — one price throughout | Only if the response at 7.5/46 is insufficient. Renal or hepatic impairment caps the dose at 7.5/46. |
What “working” is being measured
The number quoted everywhere for Qsymia is 8.6% mean weight loss, and it comes from CONQUER and SEQUEL, phase 3: 6.6% to 8.6% mean weight loss at 56 weeks by dose, with 62–70% of participants losing at least 5% of body weight That figure is the endpoint of a trial, not a milestone you pass on a particular week — and it is a mean, so half the participants were below it.
Appetite change is the thing most people notice first and it is commonly reported in the early weeks — at doses the label itself calls initiation rather than treatment. Conflating that with the trial figure is how “it works in a week” gets written.
The reactions the label lists in at least 5% of patients — tingling in the hands and feet, dizziness, altered taste, insomnia, constipation — cluster just after a step up rather than at a steady dose. The full label list →
Qsymia timeline, answered
- How long before Qsymia starts working?
- Two different things get called "working". Appetite changes are commonly reported within the first weeks, at doses the label describes as initiation rather than treatment. The weight-loss figure people quote is measured over a full trial at the maintenance dose, which this label does not reach before week 3. A page that answers with one number is answering only one of the two questions.
- Can the schedule be moved faster?
- That is a prescriber's decision and this page does not advise on it. What the label says is the escalation interval it was studied at; going faster is off-label territory and going slower is common where side effects are hard. The reactions the label lists — tingling in the hands and feet, dizziness, altered taste, insomnia — are typically worst just after a step up.
- Do I pay for the titration months?
- Yes, every one of them. Qsymia is $98 a month at maintenance on this site. The months before maintenance are not free trial months; they are billed at the price for that dose.
The schedule is quoted from FDA prescribing information for Qsymia (phentermine/topiramate), read directly. This page reports what the label says and does not recommend a dose or a schedule; that is a conversation with a prescriber. Information only, not medical advice.