Everything a reader is asked to decide about price — a month at a time or a year up front, a three-month bundle or a rolling plan — turns on one question that the pricing pages never answer. Is this a course of treatment that ends, or a medication taken indefinitely? Three randomized withdrawal studies have asked it directly, and they agree with each other more closely than most bodies of evidence ever do.
STEP 1, one year after the drug stopped
The STEP 1 extension followed 327 participants for a year after semaglutide 2.4 mg and lifestyle support were withdrawn. Mean weight loss to week 68 had been 17.3% on semaglutide against 2.0% on placebo. By week 120, the semaglutide group had regained 11.6 percentage points of what they lost, leaving a net loss of 5.6% from where they started[1]. Cardiometabolic improvements reverted toward baseline for most variables over the same period.
Two thirds of the loss came back in twelve months. The third that stayed is real, and it matters, and it is not what the headline figure describes. A reader deciding whether to buy a year at a prepaid rate is deciding in month one about a trajectory that is only visible at month 120.
STEP 4 separated continuing from stopping
STEP 4 ran a 20-week open-label lead-in on semaglutide, then randomized the 803 participants who reached the 2.4 mg maintenance dose to continue or to switch to placebo for 48 weeks. From week 20 to week 68, the continuing group lost a further 7.9% while the placebo group gained 6.9%, a difference of 14.8 percentage points (95% CI −16.0 to −13.5)[2]. Both groups kept the same lifestyle support throughout.
That design is what makes the finding hard to argue with. The two arms had the same starting weight, the same behavior program and the same twenty weeks of history behind them, and the only difference after randomization was whether the drug continued. Those twenty weeks are the escalation window the titration evidence describes.
SURMOUNT-4 found the same thing with tirzepatide
SURMOUNT-4 gave 783 adults an open-label 36-week lead-in on the maximum tolerated dose of tirzepatide, producing a mean reduction of 20.9%, then randomized 670 of them to continue or to switch to placebo for 52 weeks. From week 36 to week 88 the continuing group changed by −5.5% and the placebo group by +14.0%, a difference of 19.4 percentage points[3]. At week 88, 89.5% of those still on tirzepatide had kept at least 80% of the lead-in loss, against 16.6% of those switched to placebo.
What the three studies together do and do not establish
They establish that stopping is followed by regain, on both molecules, in randomized conditions, with lifestyle support held constant. They do not establish that everyone regains, that the rate is the same for everyone, or that a person who stops after reaching a goal cannot hold any of it. Group means are group means, and the STEP 1 extension’s standard deviation of 7.7 percentage points on the regain figure says plainly that the spread was wide.
They also do not tell a reader how long to stay on. That is a clinical decision made with a prescriber, and the practical version of it is often about cost rather than medicine. The cost calculator is the honest place to work out what an indefinite prescription costs at the dose you expect to sit on, rather than at the entry dose the advertisement is written around.
What this means for a prepay decision
If the evidence said treatment was a course, buying twelve months at a discount would be buying the whole thing. It says the opposite, so a twelve-month prepay is a discount on the first part of something longer, taken before the reader knows whether they tolerate the drug or reach a plateau. A month-to-month rate costs more per month and keeps that decision open, which is why the seller reviews record the standing rate rather than the prepaid rung wherever a seller publishes both.