Compound profile

Semaglutide

GLP-1

A GLP-1 receptor agonist, FDA-approved under brand names for diabetes and weight management, and the most widely used peptide of the GLP-1 class.

Reviewed for accuracy · Last reviewed July 7, 2026
ClassGLP-1 receptor agonist
RouteSubcutaneous injection
Common research range0.25 – 2.4 mg, weekly
StorageRefrigerated, ~4 weeks once mixed

Overview

Semaglutide acts on the GLP-1 receptor, which slows gastric emptying, reduces appetite, and improves blood-sugar regulation. It's approved under brand names for both type 2 diabetes and weight management, and it's the most widely used of the GLP-1 peptides. It's given as a once-weekly subcutaneous injection, usually starting low and stepping up every four weeks.

Like tirzepatide, people sourcing it independently as a vial rather than a prefilled pen often need to work out unit conversions by hand. The titration schedule and the units chart below are a starting point. Recalculate for your own vial with the calculator.

Dosing

The weight-management titration (Wegovy) begins at 0.25 mg once weekly and steps up every four weeks toward a 2.4 mg maintenance dose. The diabetes product (Ozempic) tops out lower. Vial users often convert milligrams to units by hand.

Read the full Semaglutide dosage guide →

Side effects

Nausea and diarrhea are the most common adverse events, typically transient and mild to moderate. The label carries a boxed warning for thyroid C-cell tumors.

Read the full Semaglutide side effects guide →

Storage

Keep unmixed vials refrigerated and away from light. Once reconstituted, most research reports store it refrigerated for roughly 4 weeks. See the full storage & safety guide for handling and disposal basics.

FAQ

How many units is 0.25 mg of semaglutide?At a 2.5 mg/mL concentration, 0.25 mg is 10 units on a U-100 insulin syringe. The number depends on how the vial is mixed, so recalculate from your own vial and water amount.
How is semaglutide different from tirzepatide?Semaglutide acts on the single GLP-1 receptor, while tirzepatide adds a second target (GIP). Both are once-weekly injections, but they're different molecules with different dosing.
Is compounded semaglutide the same as the branded pen?The active peptide is the same molecule, but independently compounded or sourced vials carry no guarantee of the purity or accuracy testing that a regulated pharmacy product does.

References

  1. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)New England Journal of Medicine · 2021 · PMID 33567185 · DOI 10.1056/NEJMoa2032183
  2. WEGOVY (semaglutide) injection: DailyMed labelDailyMed (U.S. National Library of Medicine) · current · DailyMed setid ee06186f-2aa3-4990-a760-757579d8f77b
  3. OZEMPIC (semaglutide) injection: DailyMed labelDailyMed (U.S. National Library of Medicine) · current · DailyMed setid fdf509ac-7ae5-49be-9a3e-8465c76f38e1
  4. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2)New England Journal of Medicine · 2021 · PMID 34170647 · DOI 10.1056/NEJMoa2107519
Running this protocol? PepHub can log your weekly doses and remind you.Learn more →

This page is an independent educational reference and is not medical advice. Talk to a doctor before starting or adjusting any compound.