GLP-1 Dosing Calculator
GLP-1: Incretin hormone powering modern weight loss drugs.
Pre-filled with the most-reported clinical reconstitution protocol for GLP-1. See how 1 mL and 2 mL of bacteriostatic water change concentration and syringe-draw volume, then adjust the calculator below for your own vial.
Quick answer · Clinical protocol
A 5 mg vial of GLP-1 reconstituted with 2 mL of bacteriostatic water yields a concentration of 2.50 mg/mL. At that concentration, a 250 mcg dose of GLP-1 equals 10 units on a U-100 insulin syringe (0.100 mL). GLP-1 is typically administered once weekly.
GLP-1 reconstitution: 1 mL vs 2 mL bac water
Bacteriostatic water volume is flexible. Less water means higher concentration and smaller injection volumes; more water means lower concentration and easier dose precision. Both options below are valid for a 5 mg vial.
| BAC water added | Concentration | Volume per 250 mcg dose | Draw on U-100 syringe (units) |
|---|---|---|---|
| 1 mL | 5.00 mg/mL | 0.050 mL | 5 units |
| 2 mL | 2.50 mg/mL | 0.100 mL | 10 units |
Calculate your GLP-1 dose
Alternative GLP-1 protocols
Beyond the default above, GLP-1 is also reported in the following protocols. Use these as starting points and recalculate with the tool above.
GLP-1 Class Overview
Community- Dose
- Varies by specific agonist
- Frequency
- Daily to weekly depending on specific agent
- Duration
- Ongoing (typically indefinite for weight management)
- Route
- Various
GLP-1 is the endogenous hormone; community use centers on synthetic analogs (semaglutide, tirzepatide, liraglutide); see individual peptide pages for specific protocols
Obesity (semaglutide injectable)
Clinical- Dose
- 0.25 mg escalating to 2.4 mg weekly
- Frequency
- Once weekly subcutaneous
- Duration
- Chronic therapy (weight regain upon discontinuation)
16-week titration schedule; target dose 2.4 mg weekly
Type 2 diabetes (liraglutide)
Clinical- Dose
- 0.6 mg escalating to 1.8 mg daily
- Frequency
- Once daily subcutaneous
- Duration
- Chronic therapy
Start 0.6 mg x 1 week, increase to 1.2 mg, then 1.8 mg
Obesity (liraglutide)
Clinical- Dose
- 0.6 mg escalating to 3.0 mg daily
- Frequency
- Once daily subcutaneous
- Duration
- Chronic therapy
Weekly dose escalation from 0.6 mg to target 3.0 mg over 5 weeks
Type 2 diabetes and obesity (tirzepatide)
Clinical- Dose
- 2.5 mg escalating to 15 mg weekly
- Frequency
- Once weekly subcutaneous
- Duration
- Chronic therapy
Start 2.5 mg x 4 weeks; increase by 2.5 mg every 4 weeks to target
GLP-1 reconstitution & storage
GLP-1 receptor agonists are supplied as pre-filled injection pens ready for use. No reconstitution is required. Native GLP-1 for research use is reconstituted in sterile buffer per manufacturer specifications.
Pre-filled pens: Store refrigerated at 2-8 degrees C before first use. After first use, may be stored at room temperature (up to 30 degrees C) for the product-specific in-use period (14-56 days depending on product). Do not freeze.
GLP-1 dosing FAQ
How much bacteriostatic water should I add to a 5 mg vial of GLP-1?
The community standard is 2 mL of bacteriostatic water for a 5 mg GLP-1 vial. That gives a concentration of 2.50 mg/mL, so a 250 mcg dose is 10 units on a U-100 insulin syringe. Adding 1 mL instead doubles the concentration to 5.00 mg/mL and halves the draw to 5 units. Less water = smaller injection volume but harder to measure precisely.
How many syringe units is a 250 mcg dose of GLP-1?
On a standard U-100 insulin syringe, a 250 mcg dose of GLP-1 is 10 units when the 5 mg vial is reconstituted with 2 mL of bacteriostatic water (2.50 mg/mL). If you use 1 mL of bac water instead, draw 5 units (5.00 mg/mL).
What is the standard GLP-1 dose?
Clinical protocols for GLP-1 typically use 0.25 mgâ2 mg once weekly via subcutaneous injection. 250 mcg is a common starting dose. Start 0.25 mg x 4 weeks, then 0.5 mg; may increase to 1.0 mg then 2.0 mg
How long does a vial of GLP-1 last at 250 mcg once weekly?
A 5 mg vial of GLP-1 contains roughly 20 doses at 250 mcg per injection. At once weekly dosing, that is approximately 140 days (about 20 weeks) of supply per vial. Reconstituted GLP-1 should generally be used within 28 days when refrigerated.
Where do you inject GLP-1?
GLP-1 is typically injected subcutaneously. Common sites reported in the literature and by users include: Subcutaneous (abdomen, thigh, upper arm). Rotate sites with each injection to reduce localized irritation.
Can I use sterile water instead of bacteriostatic water for GLP-1?
Bacteriostatic water (containing 0.9% benzyl alcohol as a preservative) is strongly preferred for multi-dose vials like GLP-1 because it inhibits microbial growth and lets a single vial be used over multiple weeks. Sterile water has no preservative and should generally be reserved for single-use preparations only.
More on GLP-1
Medical Disclaimer
This website is for educational and informational purposes only. The information provided is not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before using any peptide or supplement.