Semaglutide (Injectable)
Ozempic · Wegovy
Half-life
7 days
Time to Peak
36 hr
Steady State
~35 days
Bioavailability
89%
Dose Range
0.25–2.4 mg
Frequency
Weekly
Overview
Semaglutide is a once-weekly GLP-1 receptor agonist used for type 2 diabetes (Ozempic) and chronic weight management (Wegovy). It's the most widely prescribed GLP-1 medication globally and has become the benchmark for injectable weight loss therapies.
Mechanism of Action
GLP-1 receptor agonist with 94% homology to native GLP-1. Albumin-binding fatty acid side chain extends half-life to ~1 week.
Dosing Information
| Route | Dose Range | Half-life | Tmax | Frequency |
|---|---|---|---|---|
| Subcutaneous (SubQ) | 0.25–2.4 mg | 7 days | 36 hr | Weekly |
Common Side Effects
- · Nausea (especially during titration)
- · Vomiting
- · Diarrhea
- · Constipation
- · Abdominal pain
- · Injection site reactions
- · Headache
- · Fatigue
Monitoring Recommendations
HbA1c every 3 months if diabetic. Lipid panel and liver enzymes at baseline and 6 months. Monitor for pancreatitis symptoms. Thyroid function if symptomatic (rare but FDA-boxed warning for medullary thyroid carcinoma in rodents).
Storage & Handling
Refrigerated
Up to 56 days in-use (Ozempic) / 28 days (Wegovy)
Room Temperature
Up to 56 days at 15-30°C (Ozempic) / 28 days (Wegovy)
General
Store unused pens refrigerated at 2-8°C. Do not freeze. Protect from light.
Community Notes
Most users titrate slowly over 4-8 weeks to manage nausea. Injection day timing doesn't matter much — pick a consistent day. Many users report the appetite suppression effect varies week to week, especially in the first few months.
Used in Regimens
9 regimensCompounded Semaglutide — Standard Protocol
Compounded semaglutide base (not brand-name Ozempic/Wegovy) from a 503B or 503A pharmacy. Same active molecule, lower cost. FDA allowed compounding during Wegovy/Ozempic shortage; FDA shortage status may change — verify legal status in your jurisdiction.
Compounded semaglutide standard titration protocol.
GLP-1 Switch — Liraglutide → Semaglutide
Transition from liraglutide (Saxenda, daily injection) to semaglutide (Ozempic/Wegovy, weekly injection). Semaglutide produces superior weight loss at equivalent or lower doses and requires only weekly injections vs daily.
Semaglutide standard titration — start at 0.25mg week 1.
GLP-1 Switch — Semaglutide → Tirzepatide
Transition from semaglutide to tirzepatide — typically for improved efficacy or to access dual GIP/GLP-1 mechanism. Often done after plateau on semaglutide. Most patients experience renewed weight loss momentum after switching.
Semaglutide — final dose before switch.
GLP-1 Switch — Tirzepatide → Semaglutide
Transition protocol from tirzepatide to semaglutide — typically due to cost, supply, or insurance coverage change. Approximate dose equivalences: tirzepatide 5mg ≈ semaglutide 0.5mg; tirzepatide 10mg ≈ semaglutide 1mg; tirzepatide 15mg ≈ semaglutide 2mg. Expect temporary appetite increase during transition.
Semaglutide — start at one step below dose equivalent.
Semaglutide — Maintenance Dose Reduction
Deliberate step-down from peak semaglutide dose to a lower maintenance dose after reaching goal weight, while maintaining weight loss and tolerating reduced appetite suppression. Reduces cost and side effect burden.
Wegovy reduced maintenance dose — step down from peak.
Semaglutide — Slow Titration (GI-Sensitive)
Semaglutide dose escalation at half-speed for patients with significant GI side effects. Spend 4 weeks at each dose instead of the standard 4-week label schedule. Sacrifices speed of weight loss for tolerability.
Wegovy slow titration — 4 weeks at each dose level.
Data Sources
- FDA Label Ozempic FDA Prescribing Information
- FDA Label Wegovy FDA Prescribing Information
Related Tools
Track Semaglutide (Injectable) with Doseline
Reminders, medication level charts, injection site rotation, and protocol tracking — all free, all private.
Join the waitlistDoseline provides informational tools only. It is not a medical device and does not provide medical advice. Always consult a qualified healthcare provider.