How many units is your sermorelin dose?
Short answer: it depends on your vial, and a fixed “X units” figure floating around online can't account for that. Here's why, two worked examples to make it concrete, and a calculator below that works out the real number for your specific vial.
Why there's no single “units to mg” conversion
A syringe unit is a measurement of volume, not drug quantity — on a standard U-100 insulin syringe, 100 units always equals 1 mL, regardless of what's dissolved in that mL. How much sermorelin is in that mL depends on the vial's concentration — the mg of drug per mL of fluid once it's reconstituted — which is not fixed for compounded sermorelin the way an FDA-approved product's strength would be.
Sermorelin's only FDA-approved product, Geref, was approved in two fixed vial strengths (0.5 mg and 1 mg per vial — see the reference box on the main sermorelin calculator page for the sourcing), but it's discontinued and was approved for pediatric growth-hormone deficiency, not the adult-wellness use compounded sermorelin is sold for today. Compounded sermorelin vials instead state a total mg amount (commonly 5 mg, 10 mg, or similar), which gets reconstituted by adding a chosen volume of bacteriostatic water — and that chosen volume is not standardized across pharmacies. A 5 mg vial mixed with 5 mL is half as concentrated as the same 5 mg vial mixed with 2.5 mL, so “20 units” of one vial delivers a different amount of sermorelin than “20 units” of the other.
One more wrinkle specific to sermorelin: doses are usually discussed in micrograms (mcg), not milligrams — a typical compounded dose runs roughly 200-500 mcg, which is 0.2-0.5 mg. The calculator below takes your dose in mg, so convert mcg to mg first by dividing by 1,000 (500 mcg = 0.5 mg) before entering it.
Two worked examples
These use round, clearly hypothetical numbers to show the arithmetic. They are examples of the math, not a claim about what your vial contains — use the calculator below with your own vial's actual numbers for a real answer.
Example A
Say a 5 mg vial is reconstituted with 5 mL of bacteriostatic water. That's a concentration of 5 mg ÷ 5 mL = 1 mg/mL (1,000 mcg/mL). At that concentration, 20 units (0.2 mL) works out to 0.2 mL × 1 mg/mL = 0.2 mg (200 mcg).
Example B
Same 5 mg vial, but reconstituted with only 2.5 mL. That's a concentration of 5 mg ÷ 2.5 mL = 2 mg/mL (2,000 mcg/mL) — twice as strong. At that concentration, the same 20 units (0.2 mL) works out to 0.2 mL × 2 mg/mL = 0.4 mg (400 mcg) — double Example A's answer, from the identical syringe reading.
Same vial size, same syringe reading, different diluent volume — a 2× difference in the actual dose. That gap is exactly why a bare “20 units = X mcg” answer found online can be wrong for a real vial.
Convert your actual vial
Enter your vial's labeled mg amount, how much diluent you (or your pharmacy) added, and the dose your prescriber told you to take, in mg — the calculator works out your real concentration, draw volume, and syringe reading.
Not sure what your vial's mg or mL are?
Check the vial's label or your pharmacy's paperwork — the total mg is printed on the vial itself, and the diluent volume is whatever you (or the pharmacy) added when reconstituting it, not a number the vial states on its own. If either figure is unclear, or your dose was given to you in mcg and you're unsure of the mg conversion, ask your prescriber or pharmacist before drawing anything up.
Where to go next
- Use the full reconstitution tool with more reference context on the main sermorelin calculator.
- See how the providers selling sermorelin compare on our sermorelin provider board.
- Read the evidence behind sermorelin, ipamorelin, and CJC-1295 in our evidence review.
Medical disclaimer: This content is for general educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional before starting, stopping, or changing any treatment.