Research

Hormonal

Semaglutide (both oral and subcutaneous formulations) is associated with a high incidence of mild-to-moderate, transient gastrointestinal adverse effects (nausea, vomiting, diarrhea), which are dose-dependent and time-dependent, occurring primarily during the initial 8-12 weeks of treatment.

If you start semaglutide, expect some nausea, vomiting, or diarrhea, especially in the first few months. This is common and usually gets better. To minimize this, start with the lowest dose and follow the doctor's schedule for increasing it slowly. Eat smaller, slower meals and avoid fatty foods. If you take the oral version, take it on an empty stomach with a small sip of water, waiting 30 minutes before eating or drinking anything else.

StrongSupportsVERY_HIGH confidence
In the phase 3 trials, both oral and subcutaneous semaglutide were associated with gastrointestinal disturbances, such as nausea, vomiting and diarrhea... Generally, the GI complaints with semaglutide occur in the first 8–12 weeks of treatment during dose escalation... and wane over time... Overall, the adverse effects are mild to moderate in severity and often self-limiting.
Mark M. Smits et al. · Frontiers in Endocrinology · 2021

Why this rating

Based on extensive phase 3 randomized clinical trials (SUSTAIN and PIONEER programs) involving thousands of participants.

Source

Safety of Semaglutide

Mark M. Smits et al. · Frontiers in Endocrinology · 2021

DOI 10.3389/fendo.2021.645563

narrative_review · n=21500Cited 267×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →