Semaglutide: research protocol, dosing & reconstitution
Also known as: Ozempic (brand), Wegovy (brand)
Quick answer
What is Semaglutide?
Semaglutide is a GLP-1 receptor agonist — a compound that mimics a gut hormone which reduces appetite and improves blood-sugar control. It is the active ingredient in the prescription drugs Ozempic and Wegovy, and the most searched compound in the entire peptide space.
What Semaglutide is
Semaglutide is a modified version of GLP-1GLP-1 (glucagon-like peptide-1)A gut hormone that stimulates insulin release, slows stomach emptying, and reduces appetite. GLP-1 receptor agonists such as semaglutide are studied and prescribed for metabolic regulation.See glossary → (glucagon-like peptide-1), a hormone the intestine releases after eating. The modifications extend its half-lifeHalf-lifeHow long it takes for half of a compound to be eliminated from the body. Half-life determines how often researchers dose a compound in protocols.See glossary → from minutes to about a week, allowing once-weekly administration.
In Canada, semaglutide is a prescription drug (Ozempic, Wegovy, Rybelsus). Versions sold by research vendors are lyophilizedLyophilizedFreeze-dried. Peptides are shipped as a lyophilized powder ('puck') because the dry form is far more stable than a solution. It must be reconstituted before use in research.See glossary → powder for Research Use OnlyRUO (Research Use Only)A regulatory classification meaning a product is sold strictly for laboratory research and is not approved, labeled, or intended for human or veterinary use.See glossary → — commonly 2 mg, 5 mg, or 10 mg vialsVialThe small sealed glass container peptides are supplied in, topped with a rubber septum that a syringe needle can pass through.See glossary → — and are not pharmaceutical products.
Mechanism of action
Semaglutide activates GLP-1 receptorsReceptorA protein on or inside a cell that binds specific signaling molecules and triggers a response. Most peptides work by binding particular receptors.See glossary →, which stimulates insulin secretion when glucose is elevated, suppresses glucagon, slows gastric emptying, and acts on appetite centers in the hypothalamus to reduce hunger. In the STEP 1 trial published in the New England Journal of Medicine, adults receiving 2.4 mg weekly lost a mean of 14.9% of body weight over 68 weeks versus 2.4% with placebo [1].
The gradual titrationTitrationStarting at a low dose and increasing gradually on a schedule. Research protocols titrate to assess tolerance — 'start low, go slow.'See glossary → schedule used in trials exists because GLP-1 receptor activation slows digestion — stepping the dose up slowly is how the clinical program managed nausea and GI effects.
What researchers study Semaglutide for
- Weight management and appetite regulation (extensive clinical data)
- Glycemic control in type 2 diabetes
- Cardiovascular outcomes research
- Neurodegenerative and addiction research (emerging)
What dose of Semaglutide do researchers use?
Research literature commonly references doses of Titrated: 0.25 mg/wk start, stepped up to 1.0–2.4 mg/wk over weeks. This is not a recommendation — the table below summarizes protocols as they appear in published literature and trial designs.
| Context | Dose | Frequency | Duration |
|---|---|---|---|
| Clinical titration reference (STEP program) | 0.25 mg → 0.5 → 1.0 → 1.7 → 2.4 mg | Once weekly, step up every 4 weeks | 16-week titration, then maintenance |
| Literature-referenced starting point | 0.25 mg | Once weekly | 4 weeks before first increase |
← Swipe to see the full table
Half-life and dosing timing
Half-life: ~7 days (once-weekly dosing). Route referenced in research: Subcutaneous, weekly. Half-life is about 7 days, which is why dosing is once weekly on a consistent day. Steady-state levels take 4–5 weeks to establish after each dose change — the reason titration steps are 4 weeks apart.
Titration: start low, go slow
The clinical schedule is the canonical start-low, go-slow example: 0.25 mg weekly for 4 weeks (a non-therapeutic tolerance dose), then stepwise increases only as GI tolerance allows. Trials held participants at each step longer when nausea appeared.
Skip the Semaglutide math
Enter vial size, water volume, and target dose — the free calculator returns concentration, injection volume, and exact U-100 syringe units.
How is Semaglutide reconstituted?
| Vial size | BAC water | Concentration | Worked example |
|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL (2,500 mcg/mL) | 0.25 mg = 0.1 mL = 10 units on a U-100 syringe |
| 10 mg | 4 mL | 2.5 mg/mL | 0.5 mg = 0.2 mL = 20 units on a U-100 syringe |
Add 2 mL of bacteriostatic waterBAC water (bacteriostatic water)Sterile water containing 0.9% benzyl alcohol, which suppresses bacterial growth. It is the standard diluent used to reconstitute lyophilized peptides for multi-dose research vials.See glossary → to a 5 mg vial: 5 ÷ 2 = 2.5 mg/mL. A 0.25 mg starting dose is 0.25 ÷ 2.5 = 0.1 mL — 10 units on a U-100 syringeU-100 syringeAn insulin syringe calibrated so that 100 units equal 1 mL. The standard syringe referenced in peptide research; each unit equals 0.01 mL.See glossary →.
New to the process? Read the full step-by-step reconstitution guide.
How long does reconstituted Semaglutide last?
Lyophilized: refrigerate. ReconstitutedReconstitutionThe process of mixing a freeze-dried (lyophilized) peptide powder with bacteriostatic water to create a solution of known concentration.See glossary →: refrigerate at 2–8°C and use within weeks (pharmaceutical pens are labeled for 56 days refrigerated — research references treat vial stability conservatively). Do not freeze after reconstitution.
What is Semaglutide stacked with in research?
Research protocols generally run GLP-1 compounds solo. The most-referenced adjustment is slowing the titration schedule to manage GI effects rather than adding compounds.
Side effects observed in research
The trial-documented profile is predominantly gastrointestinal: nausea, vomiting, diarrhea or constipation, and reduced appetite. Rarer but serious signals in the class include pancreatitis and gallbladder disease — part of why these are prescription drugs.
- Nausea
- Vomiting
- Diarrhea/constipation
- Appetite loss
Frequently asked questions
Is research semaglutide the same as Ozempic?
No. Ozempic is a regulated pharmaceutical product with verified content and sterility. Research-vendor semaglutide is a Research Use Only chemical with no pharmaceutical oversight — quality rests entirely on the vendor's third-party testing.
What is the semaglutide titration schedule in trials?
0.25 mg weekly for 4 weeks, then 0.5, 1.0, 1.7, and 2.4 mg, stepping up every 4 weeks as tolerated — a 16-week climb to full dose.
Why is semaglutide dosed once a week?
Its modifications give it a half-life of about 7 days, so a weekly dose maintains stable levels.
Is semaglutide legal to buy in Canada?
Pharmaceutical semaglutide requires a prescription. Research vendors sell it as Research Use Only, which is not approved for human use — see our guide on Canadian peptide legality for the full picture.
Related research peptides
Tirzepatide
A dual GIP/GLP-1 receptor agonist studied and prescribed for glycemic control and weight loss, generally outperforming semaglutide on weight loss in trials.
GLP-1 / MetabolicRetatrutide
An investigational triple agonist (GIP/GLP-1/glucagon) showing the largest weight-loss figures of the class in Phase 2 trials (~24% at 48 weeks, 12 mg).
Healing & RecoveryBPC-157
A synthetic peptide fragment studied for tissue repair, tendon/ligament and gut healing in animal research.
Browse all GLP-1 / Metabolic peptides or start with the beginner’s guide to research peptides.
References
- 1.Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021. PubMed ↗