Semaglutide
Semaglutide is a synthetic analogue of the gut hormone GLP-1 that lowers blood sugar and reduces appetite, and it is FDA-approved as Ozempic, Wegovy and Rybelsus.
Regulatory status: FDA-approved: Ozempic (injection) for type 2 diabetes, Wegovy (injection) for chronic weight management, Rybelsus (oral tablet) for type 2 diabetes. The current approved prescribing information for the specific product and indication governs clinical use — not community convention or anything on this page.
Default vial
5 mg
Default mix
2 mL
Reported range
0.25 → 2.4 mg
Draw (U-100)
10 u
Weekly dosing with a 4-week titration ladder mirroring approved prescribing information.
What it is
- A GLP-1 receptor agonist: a modified 31-amino-acid peptide with fatty-acid acylation that extends its half-life.
- An incretin mimetic — a peptide hormone analogue rather than a small molecule.
- Given once weekly by subcutaneous injection in the pivotal trials, titrated to a 2.4 mg maintenance dose for weight management.
- Also available as a once-daily oral tablet co-formulated with an absorption enhancer.
How it is described to act
- 1
Administered subcutaneously, or orally with an absorption enhancer; albumin binding slows its clearance.
- 2
Reported to reach tissues expressing GLP-1 receptors, including the pancreas, hypothalamus and brainstem, and the stomach.
- 3
Acts at GLP-1 receptors, stimulating glucose-dependent insulin secretion and engaging central appetite-regulating circuits.
- 4
In trial populations this was associated with reduced calorie intake, slower gastric emptying, improved glycaemic control and weight loss; individual responses varied.
What the research has looked at
Weight management (STEP programme)
- In STEP 1 (NEJM, 2021), investigators reported that participants on once-weekly semaglutide 2.4 mg lost significantly more body weight than placebo over 68 weeks.
- In STEP 8 (JAMA, 2022), researchers reported greater weight reduction with semaglutide 2.4 mg than with daily liraglutide 3.0 mg over 68 weeks.
Glycaemic control
- Trial data cited in the approved Ozempic prescribing information report HbA1c reductions versus placebo and active comparators across the SUSTAIN programme.
Strength of evidence: Approved drug (for a specific indication)
Semaglutide has completed multiple phase 3 randomised controlled trials and holds FDA approval for defined indications — the strongest evidence tier in this library.
This molecule is an approved medicine for at least one indication. Where that is the case, the approved prescribing information — not community convention — governs its use.
Reported cautions and unknowns
- Nausea, vomiting, diarrhoea and constipation are the most commonly reported adverse events across the trials and the label.
- The FDA label carries a boxed warning about thyroid C-cell tumours observed in rodents, and it is contraindicated with a personal or family history of medullary thyroid carcinoma or MEN2.
- Pancreatitis and gallbladder disease appear as warnings and precautions in the label.
- The label states it is not recommended in pregnancy and should be discontinued before a planned pregnancy, based on animal reproduction data.
References
Handling this vial
- Lyophilized vials are generally stored at 2–8 °C and kept out of light; once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after 28 days.
- Mix by aiming water down the vial wall and rolling gently — do not shake — and never re-freeze a reconstituted vial.
- Pep-Tidy cannot verify what is in your vial. Ask your supplier for a current Certificate of Analysis (HPLC/MS).
Semaglutide questions people ask
How do you reconstitute Semaglutide?
A common starting point for a 5 mg vial of Semaglutide is 2 mL of bacteriostatic water, which gives 2.5 mg per mL. Aim the water down the inside wall of the vial, let it dissolve on its own, and roll gently instead of shaking. Pep-Tidy's reconstitution calculator will recalculate the numbers for any other vial size or water volume you use.
How many units of Semaglutide is one dose?
At 2.5 mg per mL, that works out to about 10 units on a U-100 insulin syringe for a 250 mcg dose. Change the vial size, water volume, or target dose in the calculator and the syringe reading updates with it. This is arithmetic, not a dosing recommendation.
What dosing schedule is reported for Semaglutide?
Published and community sources describe 0.25 → 2.4 mg, subcutaneous, once weekly, typically run 16 weeks on. These figures describe what has been reported, not what anyone should take — talk to a licensed clinician first.
How should Semaglutide be stored?
Lyophilized Semaglutide vials are generally kept at 2–8 °C and out of light. Once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after about 28 days. Never re-freeze a reconstituted vial and never shake it.
Read this before you act on anything above
Everything on this page is a summary of what other people have published — it is not medical advice, not a recommendation, and not a dosing instruction. Reported dose ranges describe what appears in the literature or in community protocols, not what anyone should take. Talk to a licensed clinician before using any peptide.