Most people starting a GLP-1 medication like semaglutide or tirzepatide tolerate it well — but side effects are common, especially early on. The good news: the most frequent ones are predictable and usually manageable.
What is most common
Across the large trials, gastrointestinal symptoms are the most frequently reported side effects: nausea, vomiting, diarrhea, and constipation [2][3]. They are usually mild to moderate, tend to appear when your dose increases, and often ease as your body adjusts.
The clinical consensus is clear on why: these effects are largely tied to how the dose is escalated, and slow, stepwise titration is the single most effective way to reduce them [1].
Practical ways to manage nausea
- Eat smaller, slower meals. GLP-1 medications slow stomach emptying, so large meals feel worse. Stop at comfortably full.
- Favor blander, lower-fat foods when nausea is active; very fatty or very sugary meals tend to aggravate it.
- Stay hydrated — sip fluids through the day, which also helps with constipation.
- Give titration time. If a dose increase brings on symptoms, they often settle within days to a couple of weeks.
When nausea is more stubborn, a clinician may prescribe a short course of an anti-nausea medication such as ondansetron. At Bon Health, anti-nausea support is part of the program for members who need it. Anti-nausea medicine is used selectively and short-term — persistent symptoms are a reason to slow down the dose, not to medicate indefinitely [1].
Constipation and reflux
Constipation is common and usually responds to more fluids, more fiber, movement, and sometimes a gentle over-the-counter aid your clinician approves. Reflux or fullness can improve with smaller meals and not lying down soon after eating.
When to message your care team
Reach out promptly for severe or persistent vomiting, signs of dehydration, severe abdominal pain (especially pain that radiates to the back), or symptoms that stop you from keeping fluids down. These deserve a clinician's review rather than self-management.
The Bon Health approach
Every Bon program includes unlimited messaging with your care team and dose titration tailored to how you respond — so side effects get managed, not endured. Explore compounded semaglutide from $120/month or compounded tirzepatide from $170/month, each prescribed and dosed by a licensed physician.
This article is for general education and is not medical advice. It does not replace the judgment of a licensed clinician. Compounded medications are not FDA-approved. Always talk with your healthcare provider before starting, changing, or stopping any medication.