C187H291N45O59 · 4114 g/mol · PubChem CID 56843331 ↗
Semaglutide
also known as Ozempic, Wegovy, Rybelsus
Long-acting glucagon-like peptide-1 (GLP-1) receptor agonist with C-18 fatty-acid acylation that enables albumin binding and a ~7-day half-life. FDA-approved 2017 for type 2 diabetes (Ozempic) and 2021 for chronic weight management (Wegovy). The STEP-1 trial showed 14.9% body-weight reduction over 68 weeks at 2.4 mg/week. [wilding-2021]
- Class
- GLP-1 Receptor Agonist
- Half-life
- ~7 days [fda-wegovy-label-2021]
- Evidence level
- FDA-approved
- Regulatory status
- FDA-approved (US)
At a glance
SQ · Abdomen / thigh / arm · Once weekly
Primary target — GLP-1 receptor (GLP-1R) [fda-wegovy-label-2021].
Pathway — GLP-1R agonism → ↑glucose-dependent insulin secretion, ↓glucagon, ↓gastric emptying, ↓appetite via hypothalamic centres.
Downstream effect — Improved glycemic control, reduced caloric intake, body-weight reduction, cardiovascular risk reduction [wilding-2021].
Origin — Modified GLP-1(7-37) with two amino-acid substitutions and C-18 fatty-acid acylation for albumin binding and 168-h half-life [fda-wegovy-label-2021].
Feedback intact — Glucose-dependent insulin release preserves physiological feedback.
| Parameter | Value |
|---|---|
| Standard dose (T2D, Ozempic) | 0.5–1.0 mg / week [fda-wegovy-label-2021] |
| Standard dose (weight, Wegovy) | 2.4 mg / week (after 16-wk titration) [fda-wegovy-label-2021][wilding-2021] |
| Frequency | Once weekly, same day each week |
| Titration schedule | 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg over 16 weeksMitigates GI side effects. |
| Evidence basis | FDA-approved · Phase 3 RCTs [wilding-2021][fda-wegovy-label-2021] |
| Duration | Indefinite for chronic indicationDiscontinuation results in weight regain. |
| Reconstitution | Pre-mixed pen device (commercial). Research lyophilised vial: bacteriostatic water per label. |
| Timing | Any time of day, with or without food |
| Half-life | ~7 days (168 h) [fda-wegovy-label-2021] |
Reconstitution
A pure mass-to-volume utility. Enter what you have in the vial; the atlas computes the volume per dose. No prescription information.
Lab verification
Third-party lab reports tied to batch codes, re-verifiable at the issuing lab. A fact and where to re-check it — never a verdict.
- — Personal or family history of medullary thyroid carcinoma
- — Multiple endocrine neoplasia syndrome type 2
- — Pregnancy / breastfeeding
- — Hypersensitivity to semaglutide
- — Severe gastroparesis
- — History of pancreatitis
- — Diabetic retinopathy (may worsen with rapid glycemic improvement)
- 01Reconstitution / device
Commercial: pre-filled pen, no reconstitution. Research vial: per-label or bacteriostatic water.
- 02Injection site
SQ — abdomen, thigh, or upper arm. Rotate sites weekly to avoid lipohypertrophy.
- 03Timing
Once weekly, same day. Day can be changed if ≥2 days separate doses.
- 04Storage
Pen: refrigerate 2–8 °C unopened; room temp ≤30 °C up to 56 days after first use.
- 05Needle
Pen-supplied 31–34G needle. Research vial: 27–31G insulin syringe.
Frequently asked
What is the half-life of Semaglutide?
The reported half-life of Semaglutide is ~7 days. [fda-wegovy-label-2021]
How does Semaglutide work?
Semaglutide acts on GLP-1 receptor (GLP-1R). [fda-wegovy-label-2021]
Is Semaglutide FDA-approved?
Yes — Semaglutide is approved by the US FDA.
Sources
of 53 rendered claims carry a resolvable citation.
- [fda-wegovy-label-2021]WEGOVY (semaglutide) injection 2021 — WEGOVY (semaglutide) injection prescribing information
fda-label, 2021
FDA-approved for chronic weight management at 2.4 mg/week SC. - [wilding-2021]Wilding 2021 — Once-Weekly Semaglutide in Adults with Overweight or Obesity
N Engl J Med, 2021
STEP 1 trial. 1961 adults, 68 weeks, semaglutide 2.4 mg/wk. -14.9% body weight vs -2.4% placebo.