# Semaglutide over time: what the trials measured Canonical page: https://bodienvi.com/blog/semaglutide-what-to-expect-over-time Published September 22, 2026. Updated September 22, 2026. By Bodi Envi Clinical Content Team. How STEP 1 was structured over 68 weeks, what it measured at the end and how widely results varied, and what the extension found after treatment stopped. ## Why this is not a before and after Pages about semaglutide over time usually take the form of a timeline: week one, month one, month three, with a number attached to each. This guide does not, because no source it uses supplies those numbers. What the trials supply is a structure, an endpoint, a distribution of results around the endpoint, and a follow-up after treatment stopped. This guide reports each of those as the published papers and the FDA-approved label state them, so that a reader can see the shape of a course of treatment without being handed a prediction that nothing supports. This is general information and not medical advice. STEP 1 studied Wegovy®, the branded product at its approved dose. Personalized compounded semaglutide, which Bodi Envi's programs may include, is not FDA-approved, was not studied and is not equivalent to Wegovy®. Nothing here is a result you should expect; your licensed provider is the person to ask about your own course. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ## How the trial was structured STEP 1, published by Wilding and colleagues in the New England Journal of Medicine in 2021, is the reference trial for semaglutide in weight management and is the Wegovy® label's Study 2. According to the label's description, it enrolled 1,961 adults with obesity, or with overweight and at least one weight-related condition, excluding type 2 diabetes. At baseline the mean age was 46 with a range of 18 to 86, 74 percent were female, mean body weight was 105.3 kg and mean body mass index was 37.9. Participants were randomized two to one to semaglutide or placebo. The trial ran for 68 weeks in two phases. The label describes a 16 week dose escalation, the same schedule the label sets out for the approved product, from 0.25 mg through 0.5 mg, 1 mg and 1.7 mg to 2.4 mg once weekly, followed by 52 weeks at the maintenance dose. Throughout, all participants received instruction on a reduced calorie diet of roughly 500 fewer calories a day and counselling on increased physical activity, recommended at a minimum of 150 minutes a week, beginning with the first dose. The primary endpoint was measured at week 68. That structure is the first thing worth knowing about time on semaglutide. The trial's headline figure was measured a year and four months in, after four months of escalation and a year at the top dose, in people who were also following a diet and activity program for the whole period. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ## What the trial measured at the end for brand name versions According to the abstract on PubMed, the mean change in body weight from baseline to week 68 was 14.9 percent in the semaglutide group and 2.4 percent in the placebo group, a difference of 12.4 percentage points. In kilograms, the change was 15.3 kg with semaglutide against 2.6 kg with placebo. The abstract also reports the distribution of results at the endpoint, which is the closest the trial comes to describing a range. In the semaglutide group, 86.4 percent of participants lost at least 5 percent of their body weight, 69.1 percent lost at least 10 percent and 50.5 percent lost at least 15 percent. In the placebo group the corresponding figures were 31.5, 12.0 and 4.9 percent. Participants on semaglutide also had greater improvement in cardiometabolic risk factors and in self-reported physical functioning. Read as a distribution rather than a headline, those numbers say that about one in seven people on semaglutide did not reach a 5 percent loss over 68 weeks, that about a third did not reach 10 percent, and that about half did not reach 15 percent, while some lost considerably more than the mean. They also say that nearly a third of people on placebo, with the diet and activity program alone, reached a 5 percent loss. The mean sits in the middle of a wide spread, and the trial does not tell anyone where in that spread they would fall. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ## What the trial says about the early weeks for brand name versions The abstract and the label describe the escalation period and the side effects that concentrate in it, and that is the most that can be said about early weeks from the sources. Nausea and diarrhea were the most common adverse events, described by the authors as typically transient and mild to moderate and subsiding with time, and 4.5 percent of the semaglutide group discontinued because of gastrointestinal events against 0.8 percent on placebo. The label states that the escalation schedule exists to reduce those effects, that the level of semaglutide in the body settles over several weeks on each dose, and that a provider may delay a step if a dose is not tolerated. A 2026 narrative review by Lopez Delgado and colleagues in Frontiers in Medicine, found through PubMed, adds one finding about timing that is about monitoring rather than expectation: early on-treatment weight change, usually assessed within 12 to 16 weeks, is the most clinically actionable predictor of longer term outcomes, and the authors recommend structured early response monitoring. That is a reason for a provider to look at a course at around that point; it is not a number to expect at it. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ## What happened after treatment stopped with brand name medication STEP 1 was followed by an extension, published by Wilding and colleagues in Diabetes, Obesity and Metabolism in 2022, which followed a representative subset of 327 participants for a further year after all treatment, including the lifestyle intervention, ended at week 68. According to its abstract on PubMed, the semaglutide participants in that subset had lost a mean 17.3 percent by week 68 and regained 11.6 percentage points by week 120, for a net loss of 5.6 percent from the start, while placebo participants regained 1.9 of a 2.0 percent loss. Cardiometabolic improvements reverted towards baseline for most variables. The authors describe the analyses as exploratory and conclude that ongoing treatment is required to maintain improvements. The Wegovy® label describes a separate withdrawal trial, its Study 5, in which 902 patients were escalated over a 20 week run-in and those who reached 2.4 mg were randomized to continue the medication or switch to placebo for 48 weeks; the label reports that 11 percent discontinued during the run-in, most commonly for adverse reactions. The guide on this site to stopping semaglutide or tirzepatide sets out the withdrawal evidence for both molecules. So the shape of time on semaglutide, as the trials describe it, has three parts: an escalation phase where side effects concentrate, a maintenance phase over which the trial's endpoint was measured, and a period after stopping in which, on average, much of the change reversed. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ## Why no timeline predicts one person Every figure above is a mean or a proportion across a trial population on the branded product, with a reduced calorie diet and physical activity built in. Three things keep it from becoming a personal timeline. The spread was wide, as the threshold figures show. The trial studied Wegovy® at its approved dose and schedule, and no trial of this size has studied personalized compounded semaglutide, which is not FDA-approved and is not equivalent to the approved product. And a person's own course depends on their dose and how their provider escalates it, on tolerability, on adherence, on what they eat and how they move, and on factors the review above lists as still incompletely understood. Bodi Envi publishes the same position on every page: treatment is not guaranteed, a licensed healthcare provider determines whether it is appropriate for each individual patient, and individual experiences and outcomes vary. The planning tools on this site, including the weight change estimator, are arithmetic illustrations and say so in prose; they do not predict a result. The right use of the trial figures is as the background to a conversation with a provider about your own course, at the points, such as the 12 to 16 week window the review describes, where a provider would want to look. Bodi Envi is a telehealth platform and not a medical practice, pharmacy or medication manufacturer. Clinical services for applicable programs are provided by Wasef Health, PC. This guide is general information and not medical advice, the trials cited describe the branded product, and your provider is the person to ask. ## Frequently asked questions ### How long did the main semaglutide trial run for the brand name medication? STEP 1, published in the New England Journal of Medicine in 2021, ran for 68 weeks, which the Wegovy® label describes as a 16 week dose escalation followed by 52 weeks at the 2.4 mg maintenance dose. The primary endpoint was measured at week 68, not earlier. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ### What did it measure at 68 weeks? A mean change in body weight of 14.9 percent with semaglutide against 2.4 percent with placebo, equivalent to 15.3 kg against 2.6 kg. Of the semaglutide group, 86.4 percent lost at least 5 percent of body weight, 69.1 percent at least 10 percent and 50.5 percent at least 15 percent, against 31.5, 12.0 and 4.9 percent on placebo. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ### Does the trial say what happens week by week? The abstract on PubMed and the label report the endpoint, the escalation period and the thresholds, not a weekly schedule of expected change. A 2026 review in Frontiers in Medicine reports that early on-treatment change, usually assessed at 12 to 16 weeks, is the most actionable predictor of longer term outcomes, which is a statement about monitoring, not a timeline. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ### What happened after the trial ended? The STEP 1 extension, published in 2022, followed 327 participants for a year after treatment stopped. The semaglutide group had regained 11.6 percentage points of a 17.3 percent loss by week 120, a net loss of 5.6 percent from the start, and cardiometabolic measures reverted towards baseline. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ### Can I expect the trial's result? No one can be promised a trial's mean. The figures are averages across 1,961 people on the branded product, the spread around them was wide, and roughly one in seven participants on semaglutide did not lose 5 percent. Personalized Compounded semaglutide was not studied, and this guide states no outcome for anyone. Brand name studies cannot be applied to personalized compounded versions of the medications, and no studies have been completed on personalized compounded medications, so they cannot be compared. Personalized compounded versions cannot be interchanged with the brand for studies; this is educational only. Personalized compounded medications differ from commercially available brand-name products in formulation, concentration, excipients, preparation methods, and other characteristics. Accordingly, clinical data from studies involving brand-name products should not be assumed to apply to personalized compounded formulations. At this time, the studies referenced above have not evaluated the specific personalized compounded formulations being provided. Therefore, no claims of equivalence in safety, efficacy, quality, or clinical outcomes should be inferred from these studies. ### What does Bodi Envi publish about results? Only that treatment is not guaranteed, that a licensed provider determines whether it is appropriate for each individual patient, and that individual experiences and outcomes vary. The planning tools on this site illustrate arithmetic and say so; they do not predict. ## Sources - Wilding et al., Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1), New England Journal of Medicine, 2021, PubMed: https://pubmed.ncbi.nlm.nih.gov/33567185/ (checked September 2026) - Wilding et al., Weight regain and cardiometabolic effects after withdrawal of semaglutide, the STEP 1 trial extension, Diabetes, Obesity and Metabolism, 2022, PubMed: https://pubmed.ncbi.nlm.nih.gov/35441470/ (checked September 2026) - Wegovy® (semaglutide) injection prescribing information, DailyMed, revised June 2026: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ee06186f-2aa3-4990-a760-757579d8f77b (checked September 2026) - Lopez Delgado et al., Phenotypic and genomic frameworks for precision pharmacotherapy in obesity, a narrative review, Frontiers in Medicine, 2026, PubMed: https://pubmed.ncbi.nlm.nih.gov/42519802/ (checked September 2026)