The Scale Is Only One Part of the Rebound

After a GLP-1RA is withdrawn, the subject is not only body weight. The treatment state can also include changes in blood glucose control, blood pressure, lipids, and inflammation. This chapter follows those post-cessation markers and asks whether they move in parallel with weight. The evidence supports a broad return toward baseline for several measures, but it also shows why each trajectory must be read on its own rather than treated as a perfect mirror of the scale.

Glycaemia and blood pressure move toward baseline

HbA1c is a longer-term measure of average blood glucose. In the broader review, treatment commonly lowered HbA1c by about 0.5 to 1.5 percentage points. Among the studies that reported post-cessation data, virtually all observed an increase after treatment stopped. In many studies, around half of the initial reduction had returned by eight to twelve weeks. The timing and amount varied, and HbA1c rarely returned fully to its pre-treatment level even after a year.

That pattern resembles the weight result in one respect: improvement during treatment was followed by deterioration after withdrawal. It differs in another: the review could not fit a reliable time-based model for HbA1c. The studies did not measure it at consistent intervals or report it in a sufficiently uniform way. “HbA1c rose after cessation” is therefore better supported than a claim that it follows the same exponential curve as weight.

The STEP 1 extension shows this distinction within one trial. Mean HbA1c increased after semaglutide withdrawal. At week 120, the semaglutide arm still had a small relative improvement compared with placebo and an observed mean value slightly below its own baseline. That is a residual advantage, but it is not the same as preserving the full improvement seen at week 68. A group can remain somewhat better than a comparator while losing much of its earlier gain.

The glycaemic-category results make the difference between relative and absolute change especially clear. Among participants who had prediabetes at baseline, 93.6% of the semaglutide group were normoglycaemic at week 68, compared with 41.5% of the placebo group. After the year off treatment, the corresponding proportions were 43.3% and 34.0%. Many participants who had moved into the normal range during semaglutide treatment were no longer in that category at week 120. Yet the semaglutide group still had a higher proportion than the placebo group.

Both comparisons matter. Looking only at the week-120 difference could make the remaining relative advantage look like complete maintenance. Looking only at the decline within the semaglutide group could make the residual advantage disappear. The data support a more precise statement: the treatment-associated improvement eroded substantially after withdrawal, while some difference from placebo remained in this selected extension sample.

The category change also should not be interpreted as a mechanistic diagnosis.