Semaglutide taper trial protocol published in PLoS One
A newly published trial protocol turns the common question of whether to taper semaglutide before stopping into a formal randomized test, though no results are available yet.
On July 27, 2026, the journal PLoS One published the protocol for the REST trial, a randomized study designed to test whether reducing semaglutide gradually before stopping limits weight regain and cardiometabolic decline compared with stopping the drug outright [1][2]. The paper describes how the question will be tested; it reports no results [2].
The trial is an open-label, parallel-arm randomized controlled trial with a total duration of 32 weeks per participant, made up of a 16-week discontinuation phase followed by a post-discontinuation follow-up period [2]. Participants are assigned 1:1 to one of two strategies. In the first, called immediate cessation, they continue their current semaglutide dose for 16 weeks and then discontinue completely. In the second, the dose is reduced by 25% every four weeks until complete discontinuation at week 16 [2]. The published abstract describes the same two arms as gradual dose reduction over 16 weeks versus abrupt treatment discontinuation [1].
Eligible participants are men and women aged 18 to 75 with obesity, or with overweight plus adiposity-related complications. They must already be taking weekly subcutaneous semaglutide at a dose of at least 1 mg, have lost at least 10% of their pre-treatment body weight, and have had stable weight over the previous 12 weeks [2]. People with preexisting cardiovascular disease, type 2 diabetes, pregnancy, prior bariatric surgery, eating disorders, or significant kidney, liver or malignant disease are excluded [2]. The abstract describes the group more briefly as individuals living with obesity without preexisting cardiovascular disease who are receiving semaglutide for weight management and have achieved at least 10% weight loss with no further loss over the past 12 weeks [1].
The primary outcome is the difference in body weight change, in percent, between the two groups [1][2]. Secondary outcomes are 24-hour ambulatory blood pressure and fasting ghrelin levels [1][2]. The protocol also lists fasting glucose, hemoglobin A1c, lipid profile, C-reactive protein, complete blood count, electrolytes, creatinine and liver enzymes, plus questionnaires on eating behavior and a dietary intake assessment [2]. Study visits occur at baseline, 16 weeks and 32 weeks, with interim phone assessments [2]. Everyone in the trial receives standard lifestyle recommendations covering physical activity, portion control and self-monitoring of weight [2].
The rationale rests on two points the authors cite. In clinical trials, semaglutide produced mean weight loss of about 16.9% and improved blood pressure, glucose metabolism, inflammatory markers and lipid profiles [2]. But most people regain weight after abrupt withdrawal, with roughly two-thirds of the lost weight regained within one year [2]. The protocol says this rebound is likely related to compensatory changes in energy balance, including increased appetite and reduced energy expenditure [2]. There is little clinical data on the best strategy for maintaining weight and cardiometabolic benefits after semaglutide is stopped, the authors write [2]. The trial is registered as NCT07294950 [1][2] and is funded by the Heart and Stroke Foundation of Canada, which the authors say had no role in study design, data collection or analysis, the decision to publish, or preparation of the manuscript [2].
The protocol does not report how many participants will be enrolled, when enrollment opens, or when the trial is expected to finish. Those details have not been disclosed [2]. The authors state that all relevant data will be made available upon study completion [2].
Why it matters for patients
Semaglutide -- sold as Ozempic, Wegovy and Rybelsus -- is widely prescribed, and stopping it is common, whether because of cost, insurance changes, side effects or a decision to try maintenance without it. Until now, how to stop has largely been a matter of clinical judgment: the protocol notes there is little clinical data on the best strategy after discontinuation [2]. Publishing the protocol puts a specific comparison on record, with a defined primary outcome and a registered design, so the eventual result can be judged against terms set in advance rather than after-the-fact impressions [1][2].
Two limits are worth noting. The trial tests whether a taper changes weight, blood pressure and ghrelin levels; it is not designed to show that tapering prevents all weight regain or removes the need for ongoing treatment. And the eligibility rules define a narrow group: adults without cardiovascular disease or type 2 diabetes who have already lost at least 10% of their body weight and held it steady [2]. Findings may not apply to people with those conditions, or to those who have lost less weight. The protocol addresses subcutaneous semaglutide only; tapering of tirzepatide (Mounjaro, Zepbound) or orforglipron (Foundayo) is not part of this study.
A detail that matters for reading the results: the "immediate cessation" arm is not stopping on day one. Those participants stay on their current dose for 16 weeks before discontinuing, so the comparison is between a 16-week taper and a 16-week hold followed by a stop [2].
What happens next
Participants will be followed for 32 weeks from enrollment, with study visits at baseline, 16 weeks and 32 weeks [2]. Enrollment dates, target sample size and an expected completion date were not reported in the protocol [2]. The authors state that data from the study will be made available upon study completion [2].
Sources
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