Starting any new medication comes with questions about side effects. With semaglutide, most side effects are mild and temporary, but it's important to know what to expect.
Common Side Effects
The most frequently reported side effects include:
Tips for Managing Side Effects
1. Start low, go slow. Your doctor will start you on a lower dose and gradually increase it 2. Eat smaller meals. Your appetite will be reduced, so smaller portions feel more comfortable 3. Stay hydrated. Drink plenty of water throughout the day 4. Avoid fatty or heavy foods. Light, balanced meals are easier to tolerate 5. Communicate with your care team. If side effects are bothersome, we can adjust your dose
When to Contact Your Doctor
While most side effects are mild, contact your care team if you experience:
Message your Majesta care team anytime — most messages are answered within 24 hours.
This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider. Compounded medications are not FDA-approved as final products. Individual results may vary.
Frequently Asked Questions
What are the most common side effects of semaglutide?
The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, constipation, abdominal pain, reduced appetite, and indigestion. In the STEP-1 trial, around 74% of patients on semaglutide 2.4 mg reported at least one gastrointestinal side effect. Most were mild to moderate and improved over weeks as the body adjusted to the medication. Less common side effects include fatigue, dizziness, headache, injection-site reactions, and altered taste.
How long do semaglutide side effects last?
Most gastrointestinal side effects (nausea, diarrhea, constipation) peak during dose escalation and improve over the following 2 to 6 weeks as the body adjusts. Side effects that persist past 2 months at the same dose, or that worsen rather than improve, are a signal to contact your physician for dose adjustment, slower escalation, or a different treatment plan. Severe abdominal pain, persistent vomiting, signs of dehydration, vision changes, or symptoms of allergic reaction always warrant immediate medical attention.
What are the serious side effects of semaglutide to watch for?
Less common but serious risks include pancreatitis (severe persistent abdominal pain), gallbladder disease (right-upper-quadrant pain, fever, jaundice), hypoglycemia in patients also on insulin or sulfonylureas, kidney problems (often related to dehydration from vomiting or diarrhea), diabetic retinopathy complications in patients with existing retinopathy, and a boxed warning about thyroid C-cell tumors based on rodent studies (human relevance unknown). Contact your physician immediately for any of these symptoms.
How can you reduce nausea on semaglutide?
Practical approaches that help most patients: eat smaller portions and stop at the first sign of fullness, avoid high-fat or fried foods which prolong gastric emptying, hydrate steadily through the day, separate hydration from meals to reduce stomach fullness, and avoid alcohol during dose escalation. Your physician can also slow your dose increases or hold at the current dose longer if nausea is significant. Most nausea protocols built into telehealth GLP-1 programs follow these same principles.
Can semaglutide cause hair loss?
Hair shedding (telogen effluvium) was reported by a small percentage of patients in the STEP trials and is most often linked to rapid weight loss rather than the medication itself. The pattern is typically diffuse thinning that begins 2 to 4 months after weight loss accelerates and resolves over 3 to 6 months without intervention. Adequate protein intake (1.0 to 1.2 g per kg body weight per day), iron and ferritin labs, and avoiding overly aggressive caloric restriction help reduce the risk.
Majesta Health medical content is written against primary sources (FDA labels, peer-reviewed trials, HHS and CDC publications) and passes a documented compliance review before publication. We are rolling out named physician review with US-licensed clinicians from our partner MD Integrations (MDI): each reviewed article will show the reviewing physician's name, NPI, and review date. MDI is LegitScript certified and SOC 2 Type II accredited.
- US-licensed physicians affiliated with our clinical partner MD Integrations (LegitScript certified, HIPAA, SOC 2 Type II, ISO certified)
- Board-certified in primary care and obesity medicine
- Active state medical licensure required for every prescribing clinician
- Active DEA registration where applicable (note: GLP-1 medications are not controlled substances)
- Telehealth practice across the states we currently serve through the MD Integrations Medical Services Organization (coverage varies by state; see our states page)
- Dispensing pharmacy partner: Belmar Pharma Solutions (LegitScript certified, NABP accredited); Majesta prescriptions are dispensed through Belmar's state-licensed 503A compounding pharmacy