Semaglutide
GLP-1 weight-management peptide
Also known as Sema, Ozempic, Wegovy
- Evidence grade
- AApproved, phase 3 dataScale
- Half-life
- About 1 week
- Schedule
- Once weekly, subcutaneous
- Maintenance amount
- 2.40 mg
- Vial sizes sold
- 5 mg, 10 mg
Where a value is not established in people, this table says so rather than filling the box.
Semaglutide is a long-acting GLP-1 receptor agonist built from a modified version of the natural GLP-1 hormone. It is one of the most heavily studied metabolic peptides and is approved for type 2 diabetes and chronic weight management.
It binds GLP-1 receptors in the pancreas to boost glucose-dependent insulin release and lower glucagon. In the brain it acts on appetite centers to increase fullness and slow gastric emptying, which reduces food intake. A fatty-acid chain lets it bind albumin, extending its half-life to about a week. This mechanism is confirmed by large human trials.
Extensive human clinical-trial data; approved as Ozempic for type 2 diabetes and Wegovy for weight management.
- Studied for meaningful body-weight reduction in adults with overweight or obesity
- Studied for improved blood-sugar control and lower HbA1c in type 2 diabetes
- May reduce appetite and food cravings by acting on brain appetite centers
- Studied for cardiovascular risk reduction in people with diabetes and heart disease
- Nausea, vomiting, diarrhea and constipation, especially during dose increases
- Risk of gallstones and, rarely, pancreatitis
- May cause dehydration and, in some, low blood sugar when combined with other agents
- Injection-site reactions and appetite loss that can affect nutrition
A summary of the research, not medical advice. Individual benefits and risks vary, and for some of these compounds the human evidence is still early.
The published STEP 1 trial reported a mean 14.9 percent body weight reduction at 68 weeks on the 2.4 mg maintenance dose, under a slow supervised titration and behavioral support. Tolerability-wise, GI symptoms are most common in the first weeks after each dose increase and ease as the dose holds steady.
Read the full timeline →Drawn from published trial data and how the research community commonly describes this stretch. Not a fixed schedule and not medical advice.
Once weekly, subcutaneous. For research reference only, not medical advice.
| Phase | Amount |
|---|---|
| Weeks 1–4 | 0.25 mg |
| Weeks 5–8 | 0.5 mg |
| Weeks 9–12 | 1 mg |
| Weeks 13–16 | 1.7 mg |
| Weeks 17+ | 2.4 mg |
Follows the approved label titration, increasing every four weeks toward a 2.4 mg maintenance amount, chosen by response.
Higher amounts, more injections. As the weekly total climbs, it is commonly divided into two or more injections across the week, which keeps each shot small and easier to tolerate.
A rough shopping estimate at the maintenance amount. Your real needs shift with your dose and titration.
| Item | 12-week plan | 18-week plan | 24-week plan |
|---|---|---|---|
| Peptide vials (10 mg) | 1 | 2 | 4 |
| Insulin syringes (U-100) | 12 | 18 | 24 |
| Bacteriostatic water (10 mL) | 1 | 1 | 1 |
| Alcohol swabs (100-count box) | 1 | 1 | 1 |
Lyophilized: Keep the sealed powder cold and dark, near -20 °C, dry and out of light.
Reconstituted: Refrigerate the mixed vial at 2 to 8 °C, use within a few weeks and avoid freeze and thaw.
Let a cold vial reach room temperature before you open it, so it takes on less condensation.
How strong is the evidence for Semaglutide?
We grade it A on a four-point scale. Extensive phase 3 data. Approved as Ozempic and Wegovy.
What is the half-life of Semaglutide?
About 1 week. That is the figure the reported dosing frequency follows from.
What amount of Semaglutide is used in the research?
Weeks 1–4: 0.25 mg. Weeks 5–8: 0.5 mg. Weeks 9–12: 1 mg. Weeks 13–16: 1.7 mg. Weeks 17+: 2.4 mg. Follows the approved label titration, increasing every four weeks toward a 2.4 mg maintenance amount, chosen by response.
How is Semaglutide stored once reconstituted?
Refrigerate the mixed vial at 2 to 8 °C, use within a few weeks and avoid freeze and thaw.