Semaglutide
Also called Ozempic; Wegovy; Rybelsus
The active ingredient in several FDA-approved GLP-1 medicines. Depending on the product, approved uses include type 2 diabetes, weight management, and certain heart, kidney or liver conditions.
Overview
What it is
A GLP-1 receptor agonist available as weekly injections (Ozempic, Wegovy) and tablets (Rybelsus, oral Wegovy). Each brand has its own approved uses.
How it works
It helps the pancreas release insulin when blood sugar is high, slows stomach emptying and reduces appetite.
What the research shows
In STEP 1 (1,961 adults without diabetes, 68 weeks), average weight loss was about 15% versus about 2% on placebo. In SELECT, among people with heart disease and obesity but no diabetes, major cardiovascular events were about 20% lower in relative terms. After stopping, STEP 1 participants regained about two-thirds of lost weight within a year. In SURMOUNT-5, tirzepatide produced more average weight loss (20.2% vs 13.7%).
Studied for
- Type 2 diabetesapproved
- Chronic weight managementapproved
- Cardiovascular risk reductionapproved
- MASH liver disease, stages F2-F3accelerated approval
Safety and regulatory status
Safety and side effects
Common side effects are nausea, vomiting, constipation, diarrhea and stomach discomfort. It carries a boxed warning for thyroid C-cell tumors seen in rodents and is contraindicated with a history of medullary thyroid cancer or MEN2. Other concerns include pancreatitis, gallbladder disease, worsening diabetic eye disease and low blood sugar with insulin. Stop at least two months before a planned pregnancy, and tell your anesthesia team before procedures.
Regulatory status
FDA approved by prescription. Compounded semaglutide and the salt forms semaglutide sodium and acetate are not FDA approved; FDA has reported dosing errors with compounded products.
Mixing and dosing reference
Reference information only. Read before using this section.
Semaglutide (20 mg Vial) Dosage Protocol
- Vial
- 20 mg Semaglutide
- Add diluent
- 3 mL
- Concentration
- 6.67 mg/mL
- 1 unit (U-100)
- 66.67 mcg in 0.01 mL
- Route
- Subcutaneous
- How often
- Once weekly by subcutaneous administration in the cited human trials.
- Typical range
- The standard schedule shown below progresses from 0.25 mg to 2.4 mg weekly in four-week stages.
Standard Weekly Escalation Schedule
| Study Phase | Weekly Amount | U-100 Units | Volume |
|---|---|---|---|
| Weeks 1 to 4 | 0.25 mg | 3.75 units | 0.0375 mL |
| Weeks 5 to 8 | 0.5 mg | 7.5 units | 0.075 mL |
| Weeks 9 to 12 | 1 mg | 15 units | 0.15 mL |
| Weeks 13 to 16 | 1.7 mg | 25.5 units | 0.255 mL |
| Weeks 17+ | 2.4 mg | 36 units | 0.36 mL |
How to mix
- Clean the vial stopper and gather the sterile supplies required by the research procedure.
- Add 3 mL of the documented sterile diluent slowly down the vial wall.
- Gently swirl or roll until dissolved. Do not shake.
- Label the vial 6.67 mg/mL with the preparation date and follow the exact formulation storage and discard instructions.
Dosing details
- The table converts one shared schedule for this vial concentration.
- Weeks 1 to 4: 0.25 mg once weekly.
- Weeks 5 to 8: 0.5 mg once weekly.
- Weeks 9 to 12: 1 mg once weekly.
- Weeks 13 to 16: 1.7 mg once weekly.
- Week 17 onward: The usual recommended adult weight-reduction maintenance amount is 2.4 mg once weekly.
- Consistency: Vial size does not change the weekly schedule.
Storage
- Use the storage directions for the exact supplied formulation.
- Before preparation: Keep the vial dry, protected from light, and stored according to its documentation.
- After preparation: Refrigerate only as permitted by the exact formulation and diluent instructions.
- Labeling: Record the concentration, preparation date, storage conditions, and documented discard date.
- Handling: Avoid unnecessary agitation and follow the exact product instructions.
Administration technique
- General subcutaneous research technique should follow the approved institutional or laboratory procedure.
- Use a new sterile syringe and needle for every injection and each separate vial entry.
- Clean the vial stopper and selected site, then allow the surface to dry.
- Use the needle length, angle, and skinfold method specified by the governing procedure.
- Rotate sites systematically and document each administration.
- Place used sharps immediately in an appropriate sharps container.
Important notes
- Practical details for reading the schedule and vial calculations consistently.
- The weekly amounts are identical across every Semaglutide vial-size page. Only concentration, volume, U-100 units, and supply totals change.
- The injectable schedule uses four-week escalation steps before the usual 2.4 mg adult weight-reduction maintenance amount.
- The current label also allows an increase to 7.2 mg once weekly after at least four weeks at 2.4 mg when additional weight reduction is clinically indicated; that optional amount is not included in the standard table or supply totals.
- Use a new sterile syringe for each injection and place used sharps in an appropriate container.
- Record the weekly amount, calculated units, volume, date, and administration site consistently.
Protocol source: PeptideDosages.com
Common questions
Are Ozempic and Wegovy the same?
Same ingredient, different approved uses and doses.
Will I lose 15%?
That is a trial average; individual results vary.
What happens if I stop?
Many people regain weight. Plan long-term care with your prescriber.
Found in these blends
Related in Metabolic Health
Sources and further reading (6)
- DailyMed. Wegovy, Ozempic and Rybelsus prescribing information.
- Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). NEJM, 2021.
- Lincoff AM, et al. Semaglutide and cardiovascular outcomes in obesity (SELECT). NEJM, 2023.
- Wilding JPH, et al. Weight regain after semaglutide withdrawal. Diabetes Obes Metab, 2022.
- FDA. Concerns with unapproved GLP-1 drugs used for weight loss.
- Source summary: PeptideDosages.com research overview (rewritten for NVO).
Laboratory research material: GLP-1S (NVO research code) Research Use Only