Semaglutide has become one of the most researched peptides in modern science, generating enormous interest for its role as a GLP-1 receptor agonist. Originally developed for type 2 diabetes management, semaglutide research has expanded into metabolic studies, cardiovascular research, and neuroscience applications. For researchers working with lyophilized semaglutide powder, proper reconstitution and accurate dosing are essential for reliable results.

This guide covers everything you need to know about reconstituting semaglutide from powder form, calculating doses across the standard titration schedule, and storing your reconstituted solution for maximum stability. For instant calculations, use our reconstitution calculator with the semaglutide preset.

What Is Semaglutide?

Semaglutide is a synthetic analog of human glucagon-like peptide-1 (GLP-1), modified with specific structural changes that dramatically extend its half-life and potency compared to native GLP-1.

Key Characteristics

  • Molecular weight: 4,113.58 g/mol
  • Type: GLP-1 receptor agonist (modified analog)
  • Half-life: ~168 hours (~7 days) — enabling once-weekly dosing
  • Appearance: White to off-white lyophilized powder
  • Solubility: Soluble in water and bacteriostatic water
  • Stability: Exceptionally stable among peptides; up to 56 days reconstituted

Why Semaglutide Has Such a Long Half-Life

Native GLP-1 has a half-life of only 1-2 minutes in the body, making it impractical for research use. Semaglutide overcomes this through two key modifications:

  1. Fatty acid acylation: A C-18 fatty di-acid chain is attached to the peptide via a linker, allowing it to bind to albumin in the bloodstream. This albumin binding shields the peptide from enzymatic degradation and renal clearance.
  2. Amino acid substitution: An Aib (alpha-aminoisobutyric acid) substitution at position 8 provides resistance to dipeptidyl peptidase-4 (DPP-4) cleavage.

These modifications extend the half-life from minutes to approximately one week, making once-weekly dosing feasible.

Research Applications

Published research on semaglutide includes:

  • Metabolic research — Glucose homeostasis, insulin sensitivity, and metabolic rate studies
  • Body composition studies — Effects on adipose tissue distribution and lean mass preservation
  • Cardiovascular research — MACE (major adverse cardiovascular events) reduction, atherosclerosis progression
  • Neuroscience — Neuroinflammation, neuroprotection, and potential applications in neurodegenerative conditions
  • Hepatic research — Non-alcoholic steatohepatitis (NASH) and liver fat reduction
  • Renal research — Effects on kidney function and proteinuria

Disclaimer: Lyophilized semaglutide for reconstitution is sold for research purposes only. This guide does not constitute medical advice.

Semaglutide Vial Sizes and Forms

Research-grade lyophilized semaglutide is available in several sizes:

Vial Size Common Use Approximate Duration
2 mg Short protocols, dose-finding studies 2-8 weeks depending on dose
3 mg Standard research supply 3-12 weeks depending on dose
5 mg Extended protocols 5-20 weeks depending on dose
10 mg Large-scale research Multi-month protocols

Important distinction: Research-grade lyophilized semaglutide differs from branded pharmaceutical products (Ozempic®, Wegovy®), which come pre-mixed in pen injector devices. This guide covers reconstitution of lyophilized powder form only.

How to Reconstitute Semaglutide

Supplies Needed

  • Semaglutide lyophilized vial (e.g., 3 mg or 5 mg)
  • Bacteriostatic water — why BAC water is preferred
  • Insulin syringes (1 mL/100u for reconstitution; 0.5 mL/50u recommended for dosing)
  • Alcohol swabs (70% isopropyl)
  • Clean workspace
  • Vial label or marker

Step-by-Step Reconstitution

Step 1: Plan your solvent volume. This is critical because semaglutide uses a titration schedule, and you want your syringe units to be practical across all dose levels.

For a 3 mg vial, recommended solvent volumes:

BAC Water Concentration 0.25 mg dose 0.5 mg dose 1.0 mg dose 2.4 mg dose
1 mL 3,000 mcg/mL 8.3 units 16.7 units 33.3 units 80 units
1.5 mL 2,000 mcg/mL 12.5 units 25 units 50 units —
2 mL 1,500 mcg/mL 16.7 units 33.3 units 66.7 units —
3 mL 1,000 mcg/mL 25 units 50 units 100 units —

Recommended: 1.5 mL for a 3 mg vial — produces clean measurements at the 0.25 mg and 0.5 mg dose levels (12.5 and 25 units respectively).

For a 5 mg vial:

BAC Water Concentration 0.25 mg dose 0.5 mg dose 1.0 mg dose
2 mL 2,500 mcg/mL 10 units 20 units 40 units
2.5 mL 2,000 mcg/mL 12.5 units 25 units 50 units

Recommended: 2 mL for a 5 mg vial — the standard 250 mcg dose works out to exactly 10 units.

Step 2: Allow the vial to reach room temperature (5-10 minutes). Do not use microwave or warm water to accelerate this.

Step 3: Sterilize both vial stoppers with alcohol swabs. Allow to air dry.

Step 4: Draw your chosen volume of BAC water using a fresh insulin syringe.

Step 5: Insert needle into the semaglutide vial, aiming at the inside glass wall. Slowly depress the plunger, allowing water to trickle down the wall. This should take 30-60 seconds — do not rush.

Step 6: Remove the syringe. Gently swirl the vial. Semaglutide typically dissolves within 1-3 minutes. The solution should become perfectly clear and colorless.

Step 7: Label and refrigerate immediately at 2-8°C.

For the complete reconstitution process, see our step-by-step guide.

Semaglutide Dosing and Titration

Clinical Trial Titration Schedule

Published clinical research (STEP trials, SUSTAIN trials) used a gradual dose titration to minimize gastrointestinal side effects. The standard research titration:

Week(s) Weekly Dose Duration Purpose
1-4 0.25 mg (250 mcg) 4 weeks Initiation — baseline tolerance
5-8 0.5 mg (500 mcg) 4 weeks First escalation
9-12 1.0 mg (1,000 mcg) 4 weeks Second escalation
13-16 1.7 mg (1,700 mcg) 4 weeks Third escalation
17+ 2.4 mg (2,400 mcg) Maintenance Target dose (weight research)

For diabetes research protocols, the target maintenance dose is typically 1.0 mg weekly. For metabolic/weight research protocols, the target is typically 2.4 mg weekly.

Dose Calculations (5 mg Vial + 2 mL BAC Water)

With a concentration of 2,500 mcg/mL:

Weekly Dose Calculation Syringe Units Doses per Vial
0.25 mg (250 mcg) 250 ÷ 2,500 × 100 10 units 20 weeks
0.5 mg (500 mcg) 500 ÷ 2,500 × 100 20 units 10 weeks
1.0 mg (1,000 mcg) 1,000 ÷ 2,500 × 100 40 units 5 weeks
1.7 mg (1,700 mcg) 1,700 ÷ 2,500 × 100 68 units ~2.9 weeks
2.4 mg (2,400 mcg) 2,400 ÷ 2,500 × 100 96 units ~2.1 weeks

Use our calculator to instantly compute units for any dose and vial combination.

Weekly Dosing Schedule

Semaglutide’s ~7-day half-life allows once-weekly administration. Best practices for consistent dosing:

  • Choose a consistent day — administer on the same day each week
  • Timing flexibility — if you miss the scheduled day, administer within 2 days; if more than 2 days late, skip to the next scheduled dose
  • Subcutaneous administration — the standard route in all major clinical trials
  • Injection site rotation — rotate between abdomen, thigh, and upper arm in research protocols

Semaglutide vs. Tirzepatide: Key Differences

Researchers often compare these two peptides. Here’s a quick reference:

Feature Semaglutide Tirzepatide
Mechanism GLP-1 agonist (single) GIP + GLP-1 agonist (dual)
Half-life ~168 hours (~7 days) ~120 hours (~5 days)
Dosing frequency Once weekly Once weekly
Max research dose 2.4 mg/week 15 mg/week
Reconstituted stability Up to 56 days Up to 42 days
Molecular weight 4,113.58 g/mol 4,813.45 g/mol

For tirzepatide-specific protocols, see our tirzepatide reconstitution guide.

Storage and Stability

Before Reconstitution

  • Freezer (-20°C): Optimal for long-term storage — stable for 24+ months
  • Refrigerator (2-8°C): Stable for 6-12 months
  • Room temperature: Acceptable briefly during shipping; avoid prolonged exposure

After Reconstitution

Semaglutide has exceptional stability once reconstituted — among the best of all research peptides:

  • Refrigerator (2-8°C): Stable for up to 56 days when reconstituted with bacteriostatic water
  • Room temperature: Should be used within 24 hours if not refrigerated
  • Never freeze: Reconstituted solution must not be frozen

The 56-day stability window is particularly advantageous for the titration protocol, as a single reconstituted vial can be used across multiple dose levels during the escalation phase.

Stability Tips Specific to Semaglutide

  • Semaglutide is not highly photosensitive, but still store away from direct light
  • The long stability window means you can use larger vials (5-10 mg) without waste
  • Always check clarity before each dose — the solution should remain perfectly clear
  • If you notice any cloudiness or particles during the 56-day window, discard immediately

For complete storage protocols, see our peptide storage guide.

Research Protocol Planning

How Many Vials Do You Need?

Planning a full titration protocol requires calculating total peptide needed:

Standard 20-week titration (0.25 → 2.4 mg):

Phase Weeks Weekly Dose Total Peptide
Initiation 4 0.25 mg 1.0 mg
Escalation 1 4 0.5 mg 2.0 mg
Escalation 2 4 1.0 mg 4.0 mg
Escalation 3 4 1.7 mg 6.8 mg
Maintenance 4 2.4 mg 9.6 mg
Total 20 — 23.4 mg

For 23.4 mg total, you’d need:

  • Five 5 mg vials (25 mg total, with some reserve)
  • Or eight 3 mg vials (24 mg total)

Reconstitution Timing

Since each reconstituted vial is stable for 56 days, you don’t need to reconstitute all vials at once. Plan reconstitutions to align with your dose escalation schedule:

  • Vial 1: Reconstitute at Week 1 — covers 0.25 mg phase and part of 0.5 mg phase
  • Vial 2: Reconstitute when Vial 1 runs out — continues escalation
  • Continue as needed through the protocol

This approach minimizes waste and ensures you’re always working with fresh solution.

Frequently Asked Questions

How much bacteriostatic water should I add to semaglutide?

For a 5 mg vial, add 2 mL of BAC water for a concentration of 2,500 mcg/mL. For a 3 mg vial, add 1.5 mL for 2,000 mcg/mL. Both produce clean, easy-to-measure syringe units at common dose levels. Use our calculator to find the optimal volume for your specific setup.

How long does reconstituted semaglutide last?

Reconstituted semaglutide is exceptionally stable — up to 56 days when stored at 2-8°C in bacteriostatic water. This is significantly longer than most peptides (which typically last 28 days) and makes semaglutide practical for extended protocols.

What is the standard semaglutide research titration?

The standard titration from clinical trials starts at 0.25 mg weekly for 4 weeks, then escalates through 0.5 mg, 1.0 mg, and 1.7 mg (4 weeks each) to a maintenance dose of 2.4 mg weekly. The gradual increase is designed to improve tolerability.

Can semaglutide be taken daily instead of weekly?

The ~7-day half-life makes once-weekly dosing the standard protocol. Daily dosing would result in significant accumulation and is not used in published research protocols. The weekly dosing schedule provides stable blood levels throughout the week.

What’s the difference between lyophilized semaglutide and Ozempic/Wegovy?

Ozempic® and Wegovy® are branded pharmaceutical products that come pre-mixed in pen injector devices at specific concentrations. Lyophilized (research-grade) semaglutide is a powder that must be reconstituted before use. The active peptide molecule is the same, but the formulations, concentrations, and delivery devices differ.

Should I use a 0.5 mL or 1 mL syringe for semaglutide dosing?

For the lower titration doses (0.25-0.5 mg), a 0.5 mL (50 unit) syringe provides better precision since you’re drawing smaller volumes. For higher doses (1.7-2.4 mg) that require more units, a 1 mL (100 unit) syringe may be more practical. See our syringe guide for details.

Can I mix semaglutide with other peptides?

Semaglutide should generally be reconstituted and administered separately from other peptides. While chemical compatibility data exists for some combinations, the long half-life and specific dosing schedule make solo administration the standard practice in published research.

What if my semaglutide solution turns cloudy?

Cloudiness indicates degradation, contamination, or improper reconstitution. Discard the vial immediately and reconstitute a fresh one. Properly prepared semaglutide should be perfectly clear and colorless throughout its 56-day stability window.

Summary

Semaglutide is one of the most stable and researcher-friendly peptides available:

  1. Reconstitute a 5 mg vial with 2 mL BAC water → 2,500 mcg/mL
  2. Start with 250 mcg (10 units) weekly, titrate up per protocol
  3. Store refrigerated at 2-8°C — stable for up to 56 days
  4. Once-weekly dosing on a consistent day

For instant dose calculations across all titration levels, bookmark our free peptide reconstitution calculator.

For research-grade semaglutide with verified purity and batch-specific COA, researchers choose trusted suppliers like Chameleon Peptides.