Peptide Name
Semaglutide
Updated April 2026
Semaglutide Dosing Protocol
Written by Garret Grant
Founder & Lead Researcher · B.S. Civil Engineering, UCLA
Last updated: April 2026
Complete Dosing & Safety Guide for Semaglutide, a Once-Weekly GLP-1 Receptor Agonist Frequently Discussed Alongside Cagrilintide in CagriSema research, covering titration schedules, reconstitution math, side effects, and clinical trial outcomes.
Half-life
~7 days
Dose range
0.25 mg to 2.4 mg weekly
Status
FDA-approved
Developer
Novo Nordisk
Need to calculate reconstitution and dosing units? Use the Pep Pal calculator.
Quick Reference Dosing Card
Use Case
Research users commonly explore semaglutide for appetite suppression and weight-management protocols.
Aliases
Ozempic, Wegovy, Rybelsus
Category / Class
Metabolic - GLP-1 Receptor Agonist
Half-Life
~7 days (165-184 hours)
Dosing Frequency
Once weekly (subcutaneous injection) or once daily (oral tablet)
Dose Range
0.25 mg to 2.4 mg weekly (SubQ); 3 mg to 25 mg daily (oral)
Titration Schedule
0.25 mg -> 0.5 mg -> 1.0 mg -> 1.7 mg -> 2.4 mg weekly
Common Vial Sizes
2 mg, 3 mg, 5 mg, 10 mg
Route of Administration
Subcutaneous (SubQ) or Oral
Regulatory Status
FDA-approved - Ozempic (T2D, 2017), Wegovy (obesity, 2021; CV risk reduction, 2024; MASH, 2025), Rybelsus (T2D oral, 2019), Wegovy pill (obesity oral, 2025).
Developer
Novo Nordisk
Key Stat
14.9% mean body weight reduction at 68 weeks (STEP 1); 20% reduction in MACE (SELECT trial).
Featured Suppliers
Peptide Partners
Direct product match with verified supplier link.
Orbitrex Peptides
Alternate product match for supplier comparison.
Need peptides? Start with a verified source.
These are PDP's two recommended suppliers, both USA-based, Finnrick-tested, and offering the PEPPAL discount code at checkout when eligible. For a side-by-side breakdown of our two recommended suppliers, read the full comparison.
Featured Suppliers
Our #1 Pick
Peptide Partners
Our #1 supplier
Same-day FedEx 2-Day Air, 59 Finnrick tests, multi-lab coverage, and the best per-mg value make Peptide Partners the recommended source for most buyers.
Single Vial?
Orbitrex Peptides
Need one vial?
Broader selection, single-vial orders, and Finnrick A-rated quality make Orbitrex a strong alternative for one-off purchases or harder-to-find compounds.
Affiliate disclosure: some outbound supplier links are affiliate links, and we may earn a commission at no extra cost to you.
Need broader sourcing context before choosing a vendor? Compare all COA-verified suppliers in the PepPal supplier rankings.
What Is Semaglutide?
Semaglutide is one of the most widely prescribed and studied weight-loss and diabetes medications in the world. You may know it by its brand names: Ozempic (for type 2 diabetes), Wegovy (for weight management), and Rybelsus (the oral tablet form). Developed by Novo Nordisk, semaglutide belongs to a class of drugs called GLP-1 receptor agonists -- compounds that mimic a natural gut hormone (GLP-1) your body uses to regulate appetite and blood sugar. This semaglutide dosing protocol page covers everything from titration schedules to reconstitution math for research-grade vials.
What makes semaglutide different from the natural GLP-1 your body produces? Two structural modifications. First, a small change at one position in the peptide chain makes it resistant to the enzyme (DPP-4) that normally breaks down GLP-1 within minutes. Second, a fatty acid chain attached to the peptide allows it to bind to albumin -- a protein in your blood -- which dramatically extends semaglutide's half-life to approximately 7 days. That long half-life is why semaglutide only needs to be injected once per week. After injection, blood levels peak within 1-3 days and reach steady state after about 4-5 weeks of weekly dosing.
Semaglutide has one of the broadest FDA approval histories of any modern metabolic drug. Initial approval came in December 2017 for type 2 diabetes (Ozempic). In June 2021, the higher 2.4 mg dose was approved for chronic weight management (Wegovy). In March 2024, a cardiovascular risk reduction indication was added based on the landmark SELECT trial. In August 2025, Wegovy received accelerated approval for MASH -- a form of fatty liver disease with scarring (stages F2-F3) -- based on the ESSENCE trial. In December 2025, the oral Wegovy pill (25 mg) was approved for weight management. Most recently, CKD kidney protection in type 2 diabetes was added to the Ozempic label (February 2026) based on the FLOW trial.
Semaglutide is FDA-approved for multiple indications. All information on this page is for educational and research reference purposes only.
How Semaglutide Works: GLP-1 Receptor Agonism
Semaglutide works by activating a single target -- the GLP-1 receptor -- but that receptor exists in multiple organs throughout your body, which is why semaglutide affects appetite, blood sugar, digestion, and heart health all at once. Here is how each pathway contributes:
GLP-1 Pathway Infographic
GLP-1 Receptor - Appetite and Satiety Regulation
GLP-1 receptors in the hypothalamus and brainstem regulate appetite and feeding behavior. Semaglutide activates these central receptors to reduce hunger, increase satiety signaling, and decrease energy intake. This is the primary mechanism responsible for weight loss, which occurs through reduced caloric consumption rather than increased energy expenditure. In the STEP 1 trial, participants on semaglutide 2.4 mg reduced their mean body weight by 14.9% over 68 weeks.
GLP-1 Receptor - Glucose-Dependent Insulin Secretion
In the pancreas, semaglutide triggers insulin release -- but only when blood sugar is already high. This "glucose-dependent" behavior is important because it means semaglutide is much less likely to cause dangerously low blood sugar (hypoglycemia) compared to some older diabetes medications. At the same time, semaglutide reduces the release of glucagon, a hormone that raises blood sugar, further improving blood sugar control. In the SUSTAIN trials, semaglutide reduced HbA1c (a key measure of long-term blood sugar) by 1.5-1.9% at doses of 0.5-1.0 mg.
GLP-1 Receptor - Gastric Emptying
Semaglutide activates GLP-1 receptors in the gastrointestinal tract to slow gastric emptying, prolonging postprandial satiety and blunting postmeal glucose spikes. This gastric delay also explains the characteristic gastrointestinal side effects (nausea, vomiting) that are most common during dose escalation and generally transient.
GLP-1 Receptor - Cardiovascular Pathways
Semaglutide appears to protect the heart and blood vessels in ways that go beyond just weight loss. The SELECT trial found that semaglutide reduced the risk of major adverse cardiovascular events -- meaning heart attacks, strokes, and cardiovascular death, collectively known as MACE -- by 20% in people with obesity and existing heart disease. Notably, this heart benefit showed up even in participants who did not lose much weight, suggesting semaglutide has direct cardiovascular protective effects.
Together, these pathways produce the multi-system metabolic effects that underpin semaglutide's efficacy across obesity, type 2 diabetes, cardiovascular disease, MASH, and chronic kidney disease.
Tools for this Protocol
- peptide reconstitution calculator for reconstitution and units.
- dose to units converter to lock in syringe draw volume.
Semaglutide Dosing Protocol & Titration Schedule
Phase 1 - Initiation
Weeks 1-4
0.25 mg once weekly
Starting dose for tolerability only. Not a therapeutic dose. Minimal metabolic effect expected.
Phase 2 - Early Escalation
Weeks 5-8
0.5 mg once weekly
First meaningful dose. GI side effects (nausea) most likely to emerge here.
Phase 3 - Mid Escalation
Weeks 9-12
1.0 mg once weekly
Therapeutic range for T2D (Ozempic). Appetite suppression typically becomes noticeable.
Phase 4 - High Escalation
Weeks 13-16
1.7 mg once weekly
Approaching weight-management dose. Significant weight loss typically underway.
Phase 5 - Maintenance
Weeks 17+
2.4 mg once weekly
FDA-approved maintenance dose for weight management (Wegovy). 14.9% mean weight loss at 68 weeks in STEP 1.
Important Titration Notes
Titration pacing matters. The 16-week escalation schedule was designed based on clinical trial data showing that gradual dose increases significantly reduce GI side effects. In the STEP trials, GI adverse events were most common during or shortly after dose escalation and typically plateaued by week 20.
Dose flexibility: If patients do not tolerate a dose during escalation, FDA labeling permits delaying the dose increase for an additional 4 weeks at the current level. If the 2.4 mg maintenance dose is not tolerated, the dose may be temporarily reduced to 1.7 mg for 4 weeks before re-escalation.
Missed dose guidance: If a dose is missed and the next scheduled dose is more than 2 days away, administer the missed dose as soon as possible. If fewer than 2 days remain before the next scheduled dose, skip the missed dose and resume the regular weekly schedule.
T2D dosing differs: For type 2 diabetes (Ozempic), the titration starts at 0.25 mg for 4 weeks, then 0.5 mg for at least 4 weeks. Maintenance doses are 0.5 mg, 1.0 mg, or 2.0 mg weekly - maximum dose is 2.0 mg (not 2.4 mg).
Oral semaglutide (Wegovy pill): Titration is 1.5 mg daily for 4 weeks, then 4 mg -> 9 mg -> 25 mg (each for 4 weeks). Maintenance: 25 mg daily. Must be taken on an empty stomach with a small sip of water; wait 30 minutes before eating.
Semaglutide Reconstitution Guide
The table below shows how much bacteriostatic (BAC) water to add to each common semaglutide vial size and the resulting syringe volumes for each dose. "Units" refers to markings on a standard U-100 insulin syringe, where 100 units equals 1.0 mL.
Two concentration options are shown: 2.5 mg/mL (standard) and 5.0 mg/mL (concentrated). The standard 2.5 mg/mL concentration is the most common choice -- it uses more water, which makes it easier to measure small doses accurately. The 5.0 mg/mL concentrated option uses less water per vial, resulting in smaller injection volumes, but requires more precise syringe handling. Choose whichever matches your syringe comfort level and vial size.
Vial Size: 2 mg
BAC Water: 0.8 mL
Concentration: 2,500 mcg/mL (2.5 mg/mL)
0.25 mg: 0.10 mL (10 units)
0.5 mg: 0.20 mL (20 units)
1.0 mg: 0.40 mL (40 units)
1.7 mg: 0.68 mL (68 units)
2.4 mg: 0.96 mL (96 units)
Vial Size: 3 mg
BAC Water: 1.2 mL
Concentration: 2,500 mcg/mL (2.5 mg/mL)
0.25 mg: 0.10 mL (10 units)
0.5 mg: 0.20 mL (20 units)
1.0 mg: 0.40 mL (40 units)
1.7 mg: 0.68 mL (68 units)
2.4 mg: 0.96 mL (96 units)
Vial Size: 5 mg
BAC Water: 2.0 mL
Concentration: 2,500 mcg/mL (2.5 mg/mL)
0.25 mg: 0.10 mL (10 units)
0.5 mg: 0.20 mL (20 units)
1.0 mg: 0.40 mL (40 units)
1.7 mg: 0.68 mL (68 units)
2.4 mg: 0.96 mL (96 units)
Vial Size: 5 mg
BAC Water: 1.0 mL
Concentration: 5,000 mcg/mL (5.0 mg/mL)
0.25 mg: 0.05 mL (5 units)
0.5 mg: 0.10 mL (10 units)
1.0 mg: 0.20 mL (20 units)
1.7 mg: 0.34 mL (34 units)
2.4 mg: 0.48 mL (48 units)
Vial Size: 10 mg
BAC Water: 4.0 mL
Concentration: 2,500 mcg/mL (2.5 mg/mL)
0.25 mg: 0.10 mL (10 units)
0.5 mg: 0.20 mL (20 units)
1.0 mg: 0.40 mL (40 units)
1.7 mg: 0.68 mL (68 units)
2.4 mg: 0.96 mL (96 units)
Vial Size: 10 mg
BAC Water: 2.0 mL
Concentration: 5,000 mcg/mL (5.0 mg/mL)
0.25 mg: 0.05 mL (5 units)
0.5 mg: 0.10 mL (10 units)
1.0 mg: 0.20 mL (20 units)
1.7 mg: 0.34 mL (34 units)
2.4 mg: 0.48 mL (48 units)
Reconstitution Step-by-Step
- Allow the lyophilized semaglutide vial and bacteriostatic water to reach room temperature.
- Clean both vial stoppers with alcohol swabs and allow to air dry for approximately 10 seconds.
- Draw the calculated volume of bacteriostatic water using a sterile syringe.
- Inject water slowly down the inside vial wall. Do not spray directly onto the lyophilized powder.
- Gently swirl until fully dissolved. Do not shake. Solution should be clear and colorless with no visible particles.
- Label the vial with peptide name, concentration (e.g., 2.5 mg/mL), and reconstitution date.
- Refrigerate at 2-8C (35.6-46.4F) and use within 28 days. Do not freeze reconstituted solution.
Semaglutide Side Effects - What Clinical Trials Show
The most common side effects of semaglutide are stomach-related: nausea, diarrhea, vomiting, and constipation. These effects are usually worst during the first few months as the dose increases, and most people find they improve or go away with time. This safety profile comes from an extensive evidence base -- tens of thousands of participants across the STEP (obesity), SUSTAIN (T2D), and SELECT (cardiovascular) clinical trial programs.
Common gastrointestinal effects: In pooled STEP 1-3 data (semaglutide 2.4 mg), nausea occurred in 43.9% of participants vs 16.1% placebo, diarrhea in 29.7% vs 15.9%, vomiting in 24.5% vs 6.3%, and constipation in 24.2% vs 11.1%. GI events were most common during the dose-escalation period (first 16-20 weeks) and largely transient. Importantly, 99.5% of GI events were non-serious and 98.1% were mild-to-moderate in severity. Mediation analysis confirmed that GI side effects contributed less than 1 percentage point to the total weight loss observed with semaglutide.
Dose-dependent pattern: At the lower Ozempic doses used for T2D (0.5-1.0 mg), GI adverse reactions occurred in 32.7-36.4% of participants vs 15.3% with placebo - substantially lower rates than the 2.4 mg obesity dose.
Cardiovascular signal: Mean resting heart rate increased by 1-4 bpm in semaglutide-treated participants in clinical trials. Despite this modest increase, the SELECT trial demonstrated a 20% reduction in MACE in patients with established cardiovascular disease and obesity. No increase in heart failure hospitalizations was observed.
Hepatobiliary events: Gallbladder-related disorders, principally cholelithiasis (gallstones), were more common with semaglutide - approximately 2.6% vs 1.2% with placebo in the STEP trials. This is consistent with rapid weight loss across all weight-management interventions.
Diabetic retinopathy: In the SUSTAIN-6 trial (T2D), diabetic retinopathy complications occurred at higher rates with semaglutide (3.0%) vs placebo (1.8%), likely related to rapid glucose improvement in patients with pre-existing retinopathy.
Thyroid C-cell tumors (boxed warning): Semaglutide carries a boxed warning based on rodent studies showing dose-dependent thyroid C-cell tumors. Human relevance is unknown. Semaglutide is contraindicated in patients with personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).
Discontinuation rates: In STEP trials, 6.8% of patients on semaglutide 2.4 mg permanently discontinued treatment due to adverse events vs 3.2% on placebo. The most common reasons were nausea (1.8%), vomiting (1.2%), and diarrhea (0.7%).
Semaglutide Clinical Trial Results
Semaglutide has been studied in more clinical trials than any other GLP-1 medication -- over 45,000 participants across multiple programs. The table below summarizes the major published trials. Each trial name (STEP, SELECT, FLOW, etc.) is a study program with its own focus: STEP tested weight loss, SUSTAIN and PIONEER tested diabetes control, SELECT tested heart protection, FLOW tested kidney protection, and ESSENCE tested fatty liver disease (MASH).
STEP 1 (Wilding et al., NEJM 2021)
Phase 3 • 68 weeks
1,961 adults with obesity, no diabetes
-14.9% body weight (semaglutide 2.4 mg) vs -2.4% placebo. 86.4% achieved >=5% loss.
STEP 2 (Davies et al., Lancet 2021)
Phase 3 • 68 weeks
1,210 adults with T2D and overweight/obesity
-9.6% body weight (2.4 mg) vs -3.4% placebo.
STEP 3 (Wadden et al., JAMA 2021)
Phase 3 • 68 weeks
611 adults with obesity + intensive behavior therapy
-16.0% body weight (2.4 mg) vs -5.7% placebo.
STEP 5 (Garvey et al., Nature Med 2022)
Phase 3 • 104 weeks
304 adults with obesity, no diabetes
-15.2% body weight sustained at 2 years.
SELECT (Lincoff et al., NEJM 2023)
Phase 3 • 39.8 months mean follow-up
17,604 adults with CVD + overweight/obesity, no diabetes
20% reduction in MACE (HR 0.80; 95% CI 0.72-0.90; P<0.001). -9.4% body weight.
SUSTAIN-6 (Marso et al., NEJM 2016)
Phase 3 • 104 weeks
3,297 adults with T2D at high CV risk
26% MACE reduction (HR 0.74; 95% CI 0.58-0.95). First CV benefit signal for semaglutide.
FLOW (Perkovic et al., NEJM 2024)
Phase 3 • Event-driven
3,533 adults with T2D and CKD
24% reduction in kidney disease progression and CV death (HR 0.76; 95% CI 0.66-0.88).
ESSENCE (Sanyal et al., NEJM 2025)
Phase 3 • 72 weeks (Part 1)
Adults with MASH, F2-F3 fibrosis
33% achieved both steatohepatitis resolution + fibrosis improvement vs 16% placebo.
SOUL (McGuire et al., NEJM 2025)
Phase 3 • Event-driven
Adults with T2D + ASCVD/CKD
Oral semaglutide significantly reduced MACE vs placebo in T2D with high CV risk.
STEP TEENS (Weghuber et al., NEJM 2022)
Phase 3 • 68 weeks
201 adolescents (12-17 years) with obesity
-16.1% BMI reduction vs +0.6% placebo.
Semaglutide has the most extensive clinical evidence base of any GLP-1 receptor agonist, spanning over 45,000 participants across STEP, SUSTAIN, PIONEER, SELECT, FLOW, ESSENCE, and SOUL trial programs. Its FDA label expanded from a single T2D indication in 2017 to six approved indications by the end of 2025, covering type 2 diabetes, chronic weight management (injectable and oral), cardiovascular risk reduction, chronic kidney disease protection, and MASH. Part 2 of the ESSENCE trial (240 weeks, liver-related clinical events) is ongoing with results expected in 2029. The oral Wegovy pill (25 mg) was approved in December 2025 based on OASIS 4 showing 16.6% weight loss at 64 weeks. Key ongoing trials include ESSENCE Part 2 (NCT05143970) and the broader OASIS oral semaglutide obesity program.
Storage & Handling
Lyophilized (powder, sealed)
-20C (-4F) or below (freezer)
Long-term - up to 12+ months
Lyophilized (powder, sealed)
2-8C (35.6-46.4F) (refrigerator)
Several months
Lyophilized (powder, sealed)
Room temperature (during shipping)
Stable for several weeks
Reconstituted (solution)
2-8C (35.6-46.4F) (refrigerator)
Use within 28 days
Reconstituted (solution)
-20C (-4F) (frozen aliquots)
Not recommended - do not freeze reconstituted semaglutide
Protect reconstituted solutions from light. Do not freeze reconstituted semaglutide, because freezing can degrade peptide integrity. Use bacteriostatic water (0.9% benzyl alcohol) for multi-dose vials. Sterile water is single-use only and should be discarded within 24 hours. Brand-name pre-filled pens (Ozempic, Wegovy) should be stored in the refrigerator at 2-8C. After first use, pens can be stored at room temperature (up to 30C/86F) or refrigerated for up to 56 days.
Semaglutide vs. Tirzepatide vs. Retatrutide
Semaglutide, tirzepatide, and retatrutide are the three most discussed GLP-1-based compounds for weight management. They target overlapping but different receptor combinations, which translates to different efficacy levels, side effect profiles, and availability. Use this table to compare the key differences:
Receptor Targets
Semaglutide: GLP-1 only (single agonist)
Tirzepatide: GLP-1 + GIP (dual agonist)
Retatrutide: GLP-1 + GIP + Glucagon (triple agonist)
Half-Life
Semaglutide: ~7 days
Tirzepatide: ~5 days
Retatrutide: ~6 days
Dosing Frequency
Semaglutide: Once weekly
Tirzepatide: Once weekly
Retatrutide: Once weekly
Max Studied Dose
Semaglutide: 2.4 mg/week (SubQ)
Tirzepatide: 15 mg/week
Retatrutide: 12 mg/week
Peak Weight Loss (Trials)
Semaglutide: -14.9% at 68 weeks (STEP 1)
Tirzepatide: -22.5% at 72 weeks (SURMOUNT-1)
Retatrutide: -28.7% at 68 weeks (TRIUMPH-4)
FDA Status (Feb 2026)
Semaglutide: Approved (T2D, obesity, CVD, MASH, CKD, oral)
Tirzepatide: Approved (T2D, obesity)
Retatrutide: Investigational - Phase 3
CV Outcomes Data
Semaglutide: Yes - SELECT trial (20% MACE reduction)
Tirzepatide: SURPASS-CVOT ongoing
Retatrutide: TRIUMPH-3 ongoing
Unique Advantage
Semaglutide: Most indications, longest track record, CV + kidney + MASH data, oral formulation available
Tirzepatide: Superior weight loss vs semaglutide head-to-head (SURMOUNT-5)
Retatrutide: Highest observed weight loss, glucagon-driven energy expenditure, liver fat reduction
Semaglutide's unique advantage is its breadth of clinical evidence and regulatory approvals. No other GLP-1 agonist has FDA-approved indications across diabetes, obesity, cardiovascular disease, kidney disease, MASH, and an oral formulation.
In the head-to-head SURMOUNT-5 trial, tirzepatide 15 mg produced greater weight loss than semaglutide 2.4 mg (-20.2% vs -13.7%), demonstrating the efficacy advantage of dual agonism.
These compounds are not interchangeable. Dose ranges, reconstitution math, and titration schedules differ significantly.
See the tirzepatide protocol and retatrutide protocol for compound-specific guides.
Research Dispatch
Join the mailing list for new protocol and stack releases.
Get notified when new dosing references, stack breakdowns, and calculator-driven research pages go live. No multi-step signup, just the email field.
New protocol pages
Fresh stack breakdowns
Calculator-linked updates
Email signup
Short form. One field. Research updates only.
Frequently Asked Questions - Semaglutide
Q1: What is the starting dose of semaglutide?
The FDA-approved starting dose of semaglutide for weight management (Wegovy) is 0.25 mg once weekly via subcutaneous injection. This initial dose is for tolerability only and is not a therapeutic dose. After 4 weeks at 0.25 mg, the dose increases to 0.5 mg weekly, then escalates every 4 weeks through 1.0 mg and 1.7 mg until reaching the 2.4 mg maintenance dose by approximately week 17. For type 2 diabetes (Ozempic), the same 0.25 mg starting dose applies, but the maximum dose is 2.0 mg weekly.
Q2: What is semaglutide's half-life?
Semaglutide has a half-life of approximately 7 days (165-184 hours), among the longest in current GLP-1 receptor agonists. This extended half-life is achieved through a C18 fatty diacid chain at position 26 that binds to albumin in the bloodstream, protecting the peptide from rapid degradation and renal clearance. The 7-day half-life supports once-weekly subcutaneous dosing and means semaglutide takes approximately 4-5 weeks to reach steady-state concentration at each dose level. Following discontinuation, semaglutide remains in the body for approximately 5-7 weeks.
Q3: How much weight can you lose on semaglutide?
In the STEP 1 clinical trial (NEJM, 2021), participants on semaglutide 2.4 mg lost an average of 14.9% of body weight at 68 weeks (about 33.6 lbs from a baseline average of 232 lbs), compared with 2.4% with placebo. A total of 86.4% achieved at least 5% weight loss, and about one-third achieved 20% or greater loss. Results vary by population: STEP 3 with intensive behavioral therapy showed 16.0% loss, STEP 5 showed sustained 15.2% loss at 2 years, and STEP 2 in T2D showed 9.6% loss.
Q4: How do you reconstitute semaglutide?
Reconstitution applies to lyophilized semaglutide from research or compounding sources. Brand-name Ozempic and Wegovy are pre-filled pens and do not require reconstitution. A common setup is a 5 mg vial with 2.0 mL bacteriostatic water, yielding 2.5 mg/mL concentration where 0.25 mg equals 10 units on a U-100 syringe. Inject water slowly down the vial wall, gently swirl (do not shake), and refrigerate at 2-8C. Use within 28 days. For custom concentration math, use the Peptide Reconstitution Calculator: https://www.peppal.app/calculator
Q5: Is semaglutide FDA-approved?
Yes. As of February 2026, semaglutide has broad FDA approval across multiple indications and brand names. Ozempic is approved for type 2 diabetes glycemic control (2017), cardiovascular risk reduction in T2D (2020), and CKD kidney protection in T2D. Wegovy is approved for chronic weight management in adults and adolescents (2021), cardiovascular risk reduction in adults with obesity and CVD (2024), and noncirrhotic MASH with F2-F3 fibrosis (2025). The oral Wegovy 25 mg pill was approved for weight management in December 2025. Rybelsus is approved for oral T2D treatment.
Q6: What are the most common side effects?
Gastrointestinal effects are most common. In pooled STEP 1-3 data, nausea occurred in 43.9% of participants on semaglutide 2.4 mg vs 16.1% placebo, diarrhea in 29.7% vs 15.9%, vomiting in 24.5% vs 6.3%, and constipation in 24.2% vs 11.1%. These events were most frequent during dose escalation, peaked around weeks 8-20, and were usually mild-to-moderate and transient. Discontinuation due to adverse events was 6.8%. Semaglutide has a boxed warning for thyroid C-cell tumors in rodent studies and is contraindicated in patients with MTC or MEN 2.
Q7: How does semaglutide compare to tirzepatide and retatrutide?
Semaglutide is a single GLP-1 receptor agonist, tirzepatide is a dual GLP-1 + GIP agonist, and retatrutide is a triple GLP-1 + GIP + glucagon agonist. In SURMOUNT-5, tirzepatide 15 mg produced -20.2% weight loss vs -13.7% for semaglutide 2.4 mg at 72 weeks. Retatrutide Phase 3 has reported up to -28.7% at 68 weeks. Semaglutide's strength is depth of outcomes evidence: SELECT cardiovascular data, FLOW kidney protection, MASH approval evidence, and oral formulations.
Q8: What vial sizes are available for research semaglutide?
Lyophilized semaglutide is commonly offered by research suppliers in 2 mg, 3 mg, 5 mg, and 10 mg vials. The 5 mg vial is common because it supports multiple weeks at typical dose levels and pairs cleanly with 2.0 mL bacteriostatic water for 2.5 mg/mL concentration. The 10 mg vial can be more cost-effective for higher-dose or longer protocols. Concentration choice drives syringe-unit math, so select vial size and diluent volume together.
Q9: How much bacteriostatic water should be added to semaglutide?
BAC water volume depends on vial size and desired concentration. For a 5 mg vial, 2.0 mL is a common recommendation, producing 2.5 mg/mL. At this concentration, a 0.25 mg dose is 10 units and a 2.4 mg dose is 96 units on a U-100 syringe. For a 10 mg vial, 4.0 mL produces the same 2.5 mg/mL concentration. Some users choose higher concentration mixes (e.g., 5 mg in 1.0 mL), but this changes unit math significantly. Use the calculator for exact conversions.
Q10: What is the maximum dose of semaglutide studied?
The maximum FDA-approved subcutaneous dose is 2.4 mg weekly (Wegovy) for weight management. For type 2 diabetes (Ozempic), the maximum approved dose is 2.0 mg weekly. The oral formulation maximum is 25 mg daily (Wegovy pill) or 14 mg daily (Rybelsus). In SELECT, the 2.4 mg dose produced a 20% reduction in MACE. Published Phase 3 programs have not established higher subcutaneous maintenance doses than 2.4 mg weekly.
Q11: How should reconstituted semaglutide be stored?
Reconstituted semaglutide should be stored refrigerated at 2-8C (35.6-46.4F) and used within 28 days. Do not freeze reconstituted semaglutide because freezing can degrade integrity. Protect from light and label vials with reconstitution date and concentration. For brand-name pens (Ozempic, Wegovy), unused pens stay refrigerated; after first use, pens may be stored at room temperature (up to 30C/86F) or refrigerated for up to 56 days, per labeling.
Q12: What clinical trials support semaglutide?
Semaglutide has one of the largest evidence bases among GLP-1 therapies, including STEP 1-5 and STEP TEENS for obesity outcomes, SUSTAIN-6 and SELECT for cardiovascular outcomes, FLOW for CKD outcomes, ESSENCE for MASH, and SOUL for oral semaglutide cardiovascular outcomes. Across these programs, more than 45,000 participants have been studied. This breadth of data is a major reason semaglutide has expanded into multiple FDA-approved indications across metabolic and cardiorenal disease domains.
Q13: Where can I calculate reconstitution and syringe units?
Use the PepPal calculator for exact dose-to-unit conversions.
Q14: Where can I compare peptide suppliers?
Browse the PepPal supplier directory for current supplier listings.
Sources & Research
- Wilding JPH, Batterham RL, Calanna S, et al. "Once-Weekly Semaglutide in Adults with Overweight or Obesity." New England Journal of Medicine, 2021 DOI: 10.1056/NEJMoa2032183.
- Lincoff AM, Brown-Frandsen K, Colhoun HM, et al. "Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes." New England Journal of Medicine, 2023 DOI: 10.1056/NEJMoa2307563.
- Marso SP, Bain SC, Consoli A, et al. "Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes." New England Journal of Medicine, 2016 DOI: 10.1056/NEJMoa1607141.
- Perkovic V, Tuttle KR, Rossing P, et al. "Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes." New England Journal of Medicine, 2024 DOI: 10.1056/NEJMoa2403347.
- Sanyal AJ, Newsome PN, Kliers I, et al. "Phase 3 Trial of Semaglutide in Metabolic Dysfunction-Associated Steatohepatitis." New England Journal of Medicine, 2025 DOI: 10.1056/NEJMoa2413258.
- Wharton S, Calanna S, Davies M, et al. "Gastrointestinal Tolerability of Once-Weekly Semaglutide 2.4 mg in Adults with Overweight or Obesity." Diabetes, Obesity and Metabolism, 2022 DOI: 10.1111/dom.14551.
- Weghuber D, Barrett T, Barrientos-Perez M, et al. "Once-Weekly Semaglutide in Adolescents with Obesity." New England Journal of Medicine, 2022 DOI: 10.1056/NEJMoa2208601.
- McGuire DK, et al. "Oral Semaglutide and Cardiovascular Outcomes in High-Risk Type 2 Diabetes (SOUL)." New England Journal of Medicine, 2025 DOI: 10.1056/NEJMoa2501006.
- Wegovy (semaglutide) injection - Prescribing Information. FDA, 2025. PDF.
- Ozempic (semaglutide) injection - Prescribing Information. FDA, 2025. PDF.
- ClinicalTrials.gov - STEP 1 — (NCT03548935).
- Wikipedia - Semaglutide. Link.
Related Protocols
~5 days
Tirzepatide
Metabolic - GLP-1/GIP Dual Agonist
View protocol~6 days
Retatrutide
Metabolic - GLP-1/GIP/Glucagon Triple Agonist
View protocol~2-4 hours
MOTS-c
Metabolic - Mitochondrial Peptide
View protocol~220 hours
Tesofensine
Metabolic - Triple Monoamine Reuptake Inhibitor
View protocol~30 minutes
AOD-9604
Metabolic - hGH Fragment
View protocol~6-8 days (DAC)
CJC-1295
GH Secretagogue - GHRH Analogue
View protocolConvert this protocol into exact units and save it in Pep Pal with the calculate injection units.
Disclaimer & Affiliate Disclosure
Disclaimer: The information on this page is for educational and research reference purposes only. Semaglutide is FDA-approved under the brand names Ozempic, Wegovy, and Rybelsus for specific medical indications. Research-grade semaglutide discussed in the reconstitution sections is for research use only. No compounds discussed on this site are intended for unsupervised human consumption. This is not medical advice. Consult a qualified healthcare professional before considering any peptide protocol.
Affiliate Disclosure: This site contains affiliate links to vetted peptide suppliers. We may earn a commission at no extra cost to you. Our protocol content and editorial ratings are independent of affiliate relationships.