GLP-1 Receptor Agonist

Semaglutide Dosage Calculator & Guide

The most prescribed GLP-1 for weight management. Calculate your dose, understand the titration schedule, and learn what to expect.

Updated April 2026·5 min read·For educational purposes only

Semaglutide at a Glance

Also Known As
Ozempic, Wegovy, Rybelsus
Developer
Novo Nordisk
Mechanism
GLP-1
Injection Frequency
Once Weekly
Common Vial Sizes
2 mg, 3 mg, 5 mg
Storage (Reconstituted)
Refrigerate, 4-6 weeks
Route
Subcutaneous
Half-Life
~7 days

Semaglutide Dosage Calculator

Pre-filled with typical semaglutide values. Adjust to match your vial and protocol.

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What Is Semaglutide?

Semaglutide is a GLP-1 receptor agonist originally developed by Novo Nordisk for type 2 diabetes (branded as Ozempic) and later approved for chronic weight management (branded as Wegovy). It works by mimicking the incretin hormone GLP-1, which stimulates insulin secretion, suppresses glucagon release, slows gastric emptying, and reduces appetite through central nervous system signaling.

Semaglutide is one of the most widely prescribed and clinically studied peptides for weight management, with robust phase 3 trial data showing significant and sustained weight reduction in participants across multiple studies. The compounded (research-grade) version requires reconstitution from lyophilized powder, unlike the pre-filled pen formulations of Ozempic and Wegovy.

Important: Semaglutide has not been approved by the FDA for general consumer use. The information on this page is for educational and research purposes only. Always consult a qualified healthcare provider before using any peptide.

Semaglutide Dosing Protocol

Below are common dosing protocols for semaglutide based on available research and community experience:

ProtocolDoseNotes
Weeks 1-40.25 mgStarting dose; allows GI adjustment
Weeks 5-80.5 mgFirst dose escalation
Weeks 9-121.0 mgStandard therapeutic dose
Weeks 13-161.7 mgSecond escalation (if tolerated)
Week 17+2.4 mgMaximum studied dose for weight management
Tip: Use the calculator above to recalculate your syringe units whenever you adjust your dose. Bookmark this page for quick reference.

Ready to calculate? Use the calculator above or our full calculator with syringe visualization.

How to Reconstitute Semaglutide

Semaglutide comes as a lyophilized (freeze-dried) powder that must be reconstituted with bacteriostatic water before use. The process is standard for all peptides:

For a detailed step-by-step guide with visuals, see our complete peptide reconstitution guide.

Semaglutide Side Effects

Understanding potential side effects helps you use semaglutide more safely. Most side effects are dose-dependent and may improve over time.

Common Side Effects

Less Common Side Effects

If you experience severe or persistent side effects, discontinue use and contact your healthcare provider.

How to Store Semaglutide

Before reconstitution: Store lyophilized (powder) semaglutide in a cool, dry place away from direct sunlight. Refrigeration is ideal for long-term storage of unreconstituted peptides.

After reconstitution: Store the reconstituted vial upright in a refrigerator at 36-46°F (2-8°C). Do not freeze. The solution typically remains stable for 4-6 weeks. Always swab the vial stopper with an alcohol pad before each use.

Semaglutide vs. Tirzepatide vs. Retatrutide

These three peptides represent different generations of incretin-based therapies. Semaglutide targets one receptor (GLP-1), tirzepatide targets two (GLP-1 + GIP), and retatrutide targets three (GLP-1 + GIP + Glucagon). Each successive generation has shown greater efficacy in clinical trials, though semaglutide remains the most extensively studied with the longest real-world safety track record.

Your choice between them should consider availability, cost, side effect profile, and guidance from your healthcare provider. Use our tirzepatide calculator or retatrutide calculator for dosing those peptides.

Semaglutide FAQ

How is compounded semaglutide different from Ozempic or Wegovy?+
Ozempic and Wegovy are brand-name, pre-filled pen injectors manufactured by Novo Nordisk with specific FDA-approved formulations. Compounded semaglutide is the same active molecule but comes as a lyophilized powder from compounding pharmacies or research suppliers. It requires manual reconstitution with bacteriostatic water, which is what this calculator helps with.
What's the best injection site for semaglutide?+
Semaglutide is injected subcutaneously (under the skin). The most common sites are the abdomen (at least 2 inches from the navel), outer thigh, or back of the upper arm. Rotate injection sites weekly to prevent irritation or skin changes.
Can I take semaglutide with other medications?+
Semaglutide can interact with certain medications, particularly those that affect blood sugar levels (insulin, sulfonylureas) and oral medications whose absorption may be affected by delayed gastric emptying. Always inform your healthcare provider of all medications you are taking.
How quickly does semaglutide start working?+
Most people begin noticing reduced appetite within the first 1-2 weeks. Measurable weight changes typically become apparent by weeks 4-8. Maximum effects are usually seen at 3-6 months on a stable dose. The slow titration schedule helps your body adjust gradually.
What happens if I miss a semaglutide dose?+
If you miss a dose and it has been fewer than 5 days since the scheduled injection, take it as soon as possible. If more than 5 days have passed, skip the missed dose and take the next one on your regular schedule. Do not double up doses.

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