Peptide & GLP-1 Calculators
Evidence-based tools for reconstitution, dosing, and schedule planning. Built for researchers and biohackers.
New to peptides? Read our Therapeutic Peptides Guide or the BPC-157 Dosage Guide first.
Reconstitution Calculator
Mix lyophilized peptides with bacteriostatic water. Get exact concentration, volume per dose, and insulin syringe units.
Half-Life Dose Calculator
Visualize GLP-1 drug accumulation over time. See exactly when you reach steady state and how titration affects total drug levels.
Microdosing Schedule Generator
Compare once-weekly vs split dosing (2× or 3× per week). See peak reduction percentages, trough levels, and optimal injection days.
AI Peptide Coach
Get personalized dosing recommendations based on your weight, age, goals, and health history. Track progress with AI-powered guidance.
What Is a Peptide Calculator?
A peptide calculator is a tool that helps researchers work out the math behind peptide protocols — specifically reconstitution ratios, dose volumes, half-life accumulation, and injection schedules. If you've ever stared at a vial of lyophilized BPC-157 and a bottle of bacteriostatic water wondering how much water to add and how many units to draw, that's exactly what these tools solve.
The calculations aren't difficult, but they're easy to get wrong. A 5mg vial reconstituted with 2mL of BAC water gives you a very different concentration than the same vial with 1mL — and that changes every single dose. Getting this right matters.
How to Use the Reconstitution Calculator
The reconstitution calculator is the most-used tool on this page. Enter your peptide amount (in mg), how much bacteriostatic water you're adding (in mL), and your target dose (in mcg). It outputs the exact concentration per mL, the volume to draw per dose in mL, and the number of insulin syringe units — so you know exactly where to pull the plunger to.
Works for any peptide: BPC-157, TB-500, GHK-Cu, CJC-1295, Ipamorelin, Retatrutide, Semaglutide, Tirzepatide — anything sold in lyophilized form that needs mixing before use.
Half-Life Dose Calculator: Understanding Drug Accumulation
This tool is specifically designed for GLP-1 medications with long half-lives — Semaglutide (~7 days), Tirzepatide (~5 days), Retatrutide (~6 days). When you inject weekly, the drug accumulates over multiple doses before reaching a steady state. Most people don't realize their effective drug level at week 6 is significantly higher than after their first injection.
Enter your dose, frequency, and half-life, and the calculator shows the accumulation curve week by week — so you can see exactly when steady state is reached and what your actual drug levels look like over time.
Microdosing Calculator: Split Dosing vs Weekly Injections
Some researchers split their weekly GLP-1 dose across 2–3 injections per week to reduce peak-trough swings — taking a smaller amount more frequently instead of one large weekly shot. This can reduce side effects (especially nausea) while maintaining steadier blood levels.
The microdosing schedule generator compares once-weekly vs 2× or 3× weekly dosing. It outputs peak and trough levels, optimal injection days, and the percentage reduction in peak concentration you'd get from splitting the dose.
Frequently Asked Questions
How much bacteriostatic water do I add to a peptide vial?
It depends on your target dose and how concentrated you want the solution. A common approach: add 2mL of BAC water to a 5mg vial, giving you a 2.5mg/mL (2,500mcg/mL) concentration. At that concentration, a 250mcg dose = 10 units on an insulin syringe. Use the reconstitution calculator above to dial in your specific numbers.
What syringe do I use for peptide injections?
Standard insulin syringes — 29 to 31 gauge, 0.5mL or 1mL capacity. The 100-unit markings correspond to 1mL total volume. These are available at most pharmacies without a prescription.
How do I convert mcg to units on an insulin syringe?
This depends on your reconstitution concentration. Once you know your concentration (mcg per mL), divide your target dose in mcg by the concentration to get mL, then multiply by 100 to get syringe units. The reconstitution calculator does this automatically.
Can these calculators be used for GLP-1 medications?
Yes. The reconstitution calculator works for any lyophilized compound including compounded Semaglutide and Tirzepatide. The half-life and microdosing calculators are specifically designed for GLP-1 medications given their longer half-lives and weekly injection schedules.
Are these tools accurate?
The calculations are based on straightforward pharmacokinetic math and unit conversions — there's no guesswork involved. That said, all results are for research and educational purposes. Always verify with a healthcare provider before making dosing decisions.
Coming Soon
Dose timing optimizer, injection site rotation tracker, and side-effect severity logger.
All tools are for research and educational purposes only. Not medical advice. Always consult a licensed healthcare provider before starting or modifying any peptide protocol.