Semaglutide Dosage: What STEP 1 Research Reported

TL;DR

- In the STEP 1 trial, participants started at 0.25 mg once weekly and titrated up to a 2.4 mg weekly maintenance dose over the first 16 weeks (Wilding et al., 2021). - At that dose, STEP 1 reported a mean body-weight reduction of about 15 percent over 68 weeks, versus about 2.4 percent for placebo (Wilding et al., 2021). - Semaglutide is a GLP-1 receptor agonist, and different trials studied different doses: SURPASS-2 used a 1 mg weekly comparator in type 2 diabetes (Frias et al., 2021). - Weight loss plateaus over time: the STEP 5 trial reported weight measures leveling off around week 60 (Garvey et al., 2022), and stopping is linked to regain, with the STEP 1 extension reporting participants regained about two-thirds of lost weight within a year (Wilding et al., 2022). - These are research-reported ranges, not a prescription. A personal dose is a decision for a qualified clinician.

What semaglutide dosage did the STEP 1 trial study?

In STEP 1, participants began at 0.25 mg once weekly and stepped up to a 2.4 mg weekly maintenance dose over 16 weeks (Wilding et al., 2021). The trial enrolled 1961 adults and ran for 68 weeks, using a fixed dose-escalation schedule given as a once-weekly subcutaneous injection.

The ranges below reflect what published studies and commonly studied research protocols report. This is educational, not a prescription or a personal recommendation.

Why does the semaglutide dose start low and step up?

The gradual titration is designed to limit gastrointestinal side effects, which were the most commonly reported adverse events in the trial (Wilding et al., 2021). Reported events such as nausea, diarrhea, vomiting, and constipation were generally mild to moderate. Building up slowly, rather than starting at the maintenance dose, is the pattern the STEP 1 protocol used to help the body adjust.

Is the semaglutide dose the same for weight research and diabetes research?

No; the same molecule was studied at different doses depending on the research question (Wilding et al., 2021; Frias et al., 2021). STEP 1 titrated to 2.4 mg weekly to study body weight. In the SURPASS-2 diabetes trial, semaglutide was used at 1 mg weekly as an active comparator against tirzepatide (Frias et al., 2021). Because semaglutide is a GLP-1 receptor agonist studied across several programs, a single "the dose" figure does not exist. The trial and the population determine the dose studied.

What weight change did 2.4 mg weekly produce in the trial?

STEP 1 reported a mean body-weight reduction of about 15 percent over 68 weeks at 2.4 mg weekly, compared with about 2.4 percent for placebo (Wilding et al., 2021). More dose does not mean weight falls forever. In the two-year STEP 5 trial, weight measures appeared to plateau around week 60 (Garvey et al., 2022), and the body mounts metabolic adaptations, including adaptive thermogenesis, that resist further loss (Rosenbaum and Leibel, 2010).

What does research report about stopping semaglutide?

In the STEP 1 extension, participants regained about two-thirds of the weight they had lost within a year of stopping treatment (Wilding et al., 2022). This regain pattern is not unique to one compound: withdrawing tirzepatide in SURMOUNT-4 was also followed by weight regain (Aronne et al., 2024), which fits the metabolic adaptation described by Rosenbaum and Leibel (2010). The research points to these agents as ongoing rather than short-course interventions, a point for a clinician to weigh.

How does semaglutide dosage compare to tirzepatide?

They are different compounds on different dose scales, and their reported outcomes differ (Wilding et al., 2021; Jastreboff et al., 2022). The grid below sets the research side by side.

Milligram numbers are not directly comparable across compounds, because each molecule has its own potency and dose range. Comparing 2.4 mg of one to 15 mg of another says nothing on its own.

Is a research-reported dose the same as a prescription?

No; the figures on this page describe what published trials reported, and they are not a prescription or a plan for anyone to follow. Semaglutide is a GLP-1 receptor agonist, and dose selection depends on individual medical history, goals, and monitoring. Any decision about whether, what, or how much to take belongs with a qualified clinician.

Related reading

To go deeper on the science and the comparisons behind these numbers:

- [What are peptides?](/what-are-peptides) - [Semaglutide: complete research guide](/semaglutide) - [Semaglutide vs tirzepatide](/semaglutide-vs-tirzepatide) - [Tirzepatide dosage: what the trials reported](/tirzepatide-dosage)