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Semaglutide (Ozempic / Wegovy / Rybelsus)

✍️ Reviewed by nnng.com Editorial Team  ·  April 2026  ·  Medical disclaimer

The most studied GLP-1 agonist — proven 15% average body weight reduction in clinical trials.

📍 GLP-1 / Weight Loss ⏱ Once weekly 💉 SubQ (abdomen, thigh, or upper arm) 🔄 Cycle: Ongoing / long-term ⏳ Half-life: ~7 days ❄️ Storage: 28 days refrigerated

📋 What is Semaglutide?

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist. Originally developed for type 2 diabetes (Ozempic), it was subsequently approved for chronic weight management (Wegovy) at higher doses. The STEP clinical trials demonstrated an average 14.9% body weight reduction over 68 weeks.

Mechanism: GLP-1 is a hormone secreted by intestinal cells in response to food. Semaglutide mimics GLP-1, binding to receptors in the pancreas (increasing insulin, decreasing glucagon), brain (reducing appetite and food cravings), and stomach (slowing gastric emptying — increasing satiety).

✅ Key Benefits

  • Average 15% body weight reduction (STEP trials)
  • Significant reduction in appetite and food cravings
  • Improved glycemic control
  • Cardiovascular risk reduction (SELECT trial: 20% reduction in MACE)
  • Reduced liver fat (NASH)
  • Potential cognitive benefits (ongoing research)
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⚠️ Research use only. Not medical advice. Consult a licensed healthcare provider before using any peptide.

💉 Dosing Reference Table

WeekDoseNotes
1–40.25 mg/weekStarting dose — tolerance building
5–80.5 mg/weekFirst escalation
9–121.0 mg/weekTherapeutic dose for many
13–161.7 mg/weekEscalation toward max
17+2.4 mg/weekMaximum approved dose (Wegovy)
Maintenance1.0–2.4 mg/weekStay at lowest effective dose

Semaglutide must be titrated slowly to minimize GI side effects (nausea, vomiting). The titration schedule above is the FDA-approved Wegovy protocol. Many clinicians extend each step to 6–8 weeks rather than 4 to improve tolerability. Take on the same day each week. Injection can be in abdomen, front of thigh, or upper arm. Rotate sites.

🔀 Common Stacks

+ Tirzepatide (switch, not stack)
Many patients switch from semaglutide to tirzepatide for greater weight loss (~21% vs ~15%). Not typically combined — they act on overlapping pathways.
+ BPC-157
Some practitioners add BPC-157 to help with GI side effects during GLP-1 titration, leveraging BPC-157's gut-healing properties.

❓ Frequently Asked Questions

What's the difference between Ozempic and Wegovy?
Same molecule (semaglutide), different doses and approvals. Ozempic is approved for type 2 diabetes at up to 2 mg/week. Wegovy is approved for chronic weight management at 2.4 mg/week. Rybelsus is an oral form at 14 mg/day (lower bioavailability). The 2.4 mg/week dose produces more weight loss but also more side effects.
Why do I need to titrate slowly?
GLP-1 slows gastric motility. Too high a dose too quickly causes significant nausea, vomiting, and rarely, gastroparesis. The titration protocol allows GI adaptation. Most side effects occur in the first 4–8 weeks and improve substantially after. Eating smaller, lower-fat meals helps during titration.
What happens if I stop taking it?
Weight regain begins within weeks of stopping semaglutide. The STEP 4 withdrawal trial showed ~2/3 of weight lost returned within 1 year after stopping. This suggests semaglutide manages obesity chronically, similar to how antihypertensives manage blood pressure — it works while you take it.
Can I use compounded semaglutide?
Compounded semaglutide became widely available due to FDA shortage listings. Quality varies significantly between compounders. Avoid formulations containing 'semaglutide sodium' — this is not bioequivalent to the approved molecule. Acetate form is the correct salt. FDA shortage status and regulations change — verify current status.
What are the main side effects?
Nausea (44% of patients), diarrhea (30%), vomiting (24%), constipation (24%). Usually worst during titration, improve over time. Rare but serious: pancreatitis, gallbladder disease, increased heart rate. Contraindicated with personal or family history of medullary thyroid carcinoma or MEN2.

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