Tirzepatide users regained weight after stopping, SURMOUNT-CN follow-up finds

People who took tirzepatide for 52 weeks and then stopped regained weight over the next 26 weeks, but remained well below their starting weight, according to a real-world follow-up of phase 3 SURMOUNT-CN participants published in 2025 in Life Metabolism ^[1][2].

The analysis followed 152 participants from SURMOUNT-CN, a phase 3 tirzepatide trial conducted in China, all of whom completed 52 weeks of study treatment ^[1]. Fifty-seven had been assigned to tirzepatide 10 mg, 51 to tirzepatide 15 mg, and 44 to placebo ^[1]. Anyone who took another anti-obesity medication or had bariatric surgery during the 26 weeks after treatment stopped was excluded from the analysis ^[1].

Between week 52, when treatment ended, and week 78, average body weight rose 9.1% in the 10 mg group, 12.3% in the 15 mg group, and 1.8% in the placebo group ^[1]. Waist circumference rose 2.9 cm in the 10 mg group and 5.5 cm in the 15 mg group, while falling 0.5 cm in the placebo group ^[1].

Measured from the trial's start rather than from the day treatment stopped, the picture looks different. Net body weight change from week 0 to week 78 was -8.7% for the 10 mg group, -10.6% for the 15 mg group, and -2.5% for placebo ^[1]. Net waist circumference change over the same period was -10.5 cm, -10.6 cm, and -4.0 cm respectively ^[1]. The paper also reports that several cardiometabolic measures were still improved at week 78 in the tirzepatide groups ^[1].

The higher dose regained a larger share of lost weight in percentage terms, 12.3% versus 9.1%, but had also produced more loss during treatment, leaving it with the larger net loss at week 78 ^[1]. The study reports standard deviations alongside each average, and those ranges are wide, meaning individual results varied considerably ^[1].

Among the study's limits: the 26-week follow-up was observational and real-world rather than randomized, so it cannot show what would have happened under other circumstances ^[1]. It has not been reported whether weight regain levels off after 26 weeks, whether participants received structured diet or exercise support during follow-up, or how these results compare directly with withdrawal studies run in the United States or Europe. Five of the paper's authors are employees of Eli Lilly and Company, which makes tirzepatide ^[1].

Why it matters for patients

Many people taking tirzepatide eventually face a decision about stopping, whether because of cost, side effects, supply, or personal preference. This follow-up adds a non-US dataset to a body of withdrawal research that has been dominated by trials in the United States and Europe, and it points in the same general direction: stopping usually brings some weight back, but a meaningful net loss can persist for at least six months.

The gap between the two ways of measuring the same data is the practical takeaway. Weight regain after stopping was real, and it was larger at the higher dose, yet participants were still roughly 9% to 11% below their starting weight at week 78 — a range that in obesity medicine is generally considered clinically meaningful. Waist circumference, a simple measure of abdominal fat, stayed about 10.5 cm below baseline in both tirzepatide groups five to six months after the drug was stopped ^[1].

Anyone weighing whether to stop, pause, or continue a GLP-1 or dual-agonist medication should treat these averages as averages, not predictions. The wide spread in the data means some participants regained far more than the group mean and others regained little or none. The results come from people who completed a controlled clinical trial, a group that may differ from patients in routine care. Decisions about starting, stopping, or changing treatment belong with a prescribing clinician.