Dose calculator

GHRP-2 dose calculator

Convert any GHRP-2 dose into syringe units in real time, pre-filled with a 5 mg / 2 mL example.

iPhone · Free to download

Last updated: May 13, 2026

Vial (mg)

Diluent (mL)

Dose (mcg)

Dose unit

Draw on a U-100 syringe

0.00 units

Volume to draw

0.000 mL

GHRP-2 is a short-acting injectable peptide people use to trigger sharp pulses of their own growth hormone, usually paired with a GHRH like CJC-1295 or sermorelin. It mimics ghrelin at the GH-secretagogue receptor, producing a strong but brief GH spike within minutes of injection. Published studies show clear post-injection GH peaks, with some appetite increase as a side effect. This page covers reconstitution math and per-injection logging cadence.

How the GHRP-2 dose calculator works

GHRP-2 doses are 100-300 mcg, taken 1-3 times daily. On a 5 mg vial mixed with 2 mL water (2.5 mg/mL), a 100 mcg dose draws 4 units — a small draw, hard to read at low concentration. Many users mix with less water to push unit counts up.

The formula is volume in mL equals dose mg divided by concentration mg/mL, then volume times one hundred to get units on a U-100 insulin syringe. With a 2.5 mg/mL GHRP-2 solution and a 0.1 mg dose, the draw is 0.04 mL or about 4 units. Type any other dose and the unit count updates in real time — no spreadsheets, no guesswork.

Inputs that genuinely matter: concentration (which only changes when you reconstitute a new vial) and dose mass. Syringe type matters too, but only because U-100 vs U-40 changes the multiplier — almost every modern insulin syringe is U-100, which is why the math defaults to that. Edge cases worth flagging: switching from mcg to mg without checking the input unit, or carrying yesterday's unit count over to a new vial that was reconstituted with a different volume of BAC water.

Worked example

Walking one GHRP-2 dose through the math

The vial holds 5 mg of GHRP-2, mixed into 2 mL of bacteriostatic water — concentration 2.50 mg/mL.
Your 0.1 mg dose ÷ 2.50 mg/mL = 0.040 mL of solution to pull.
Multiply by 100 (because U-100 means 100 units per mL): 0.040 × 100 = 4 units.
Double the dose to 0.2 mg and the unit count doubles to 8 — the relationship is linear at a fixed concentration.
Change the diluent volume and every one of these numbers moves; change the dose alone and only the last one does.

GHRP-2 titration ladder at this concentration

What different GHRP-2 dose steps draw on a U-100 insulin syringe at the example 2.50 mg/mL concentration.

Dose (mg)	Volume (mL)	Units (U-100)
0.05	0.020	2
0.1	0.040	4
0.2	0.080	8
0.4	0.160	16

Doubling the GHRP-2 dose doubles the unit count. Halving it halves the count. Step-ups under 5 units are hard to read accurately — re-reconstitute with more water if your titration hits that range.

Scenarios people actually run into

Three things that come up logging GHRP-2

You're sitting at the 0.1 mg GHRP-2 step and your prescriber bumps you up. The new dose is double — 8 units instead of 4. Same vial, same syringe, twice the volume on the line.
Your fingers reach for the syringe and the unit count from last week is still in your head. Half the time that number is fine; the other half, the vial changed and the right answer moved. The calculator is the second pair of eyes.
You skipped a week. GHRP-2 cadence is 7 doses per week, and doubling up to "catch up" almost never reads how people expect — log the skip, then log the next normal dose.

Same-category neighbor

GHRP-2 next to Sermorelin

Both sit in the GH Secretagogue bucket — here's the dose math side by side on each one's example vial.

	GHRP-2	Sermorelin
Example dose	0.1 mg	0.2 mg
Concentration	2.50 mg/mL	2.50 mg/mL
Units to draw	4	8

Want the full breakdown? Sermorelin reference →

How GHRP-2 dosing is tracked

Published research on GHRP-2 frequently documents protocols that involve multiple administrations throughout the day, typically ranging from one to three separate doses. This dosing cadence is a direct consequence of the peptide's short half-life, a common characteristic among all synthetic ghrelin agonists that necessitates repeated stimulus to study sustained effects. A standard U-100 insulin syringe is almost universally employed for this purpose, as it provides the necessary precision to accurately measure and draw the small liquid volumes corresponding to typical dose magnitudes of around 100 micrograms.

The timing of administration is a critical variable studied in these protocols, with doses often scheduled on an empty stomach, such as upon waking or several hours after a meal. This timing is planned to prevent the potential blunting effect that circulating glucose and fatty acids can have on the pulsatile release of growth hormone. For anyone documenting a personal protocol, this makes time-stamping each log entry essential. Without this data point, a log of a three-times-daily schedule rapidly degrades into a simple tally that cannot be used to analyze patterns or correlate observed outcomes to a specific morning, mid-day, or evening administration.

A second consideration documented in the comparative literature is how a multi-dose schedule interacts with cumulative weekly exposure. Three 100 mcg doses per day for seven days produce 2,100 mcg of weekly exposure from a single 5 mg vial, which means a vial reconstituted at the example concentration of 2,500 mcg/mL lasts roughly two and a half weeks at that cadence — a useful number to know in advance when planning reorders, since running out mid-cycle disrupts whatever pattern the log was attempting to capture. Researchers who document this kind of long-running protocol typically also note ambient temperature during transport between dose times, because a vial carried in a warm bag for several hours each day is not in the same storage condition as one that lives continuously in a refrigerator, and the difference is worth recording even if the visible appearance of the solution does not change.

Common GHRP-2 dose-calculation mistakes

Using a large-volume syringe (e.g., a 3 mL syringe) that lacks the fine gradations needed to accurately measure a typical 100 mcg dose volume.
Neglecting to log the specific time of day for each dose in a multi-dose schedule, which renders later analysis of the data almost meaningless.
Administering a dose immediately following a large meal, a variable noted in research that can interfere with the peptide's primary action.

Frequently asked questions about GHRP-2 dose calculator

How does the GHRP-2 dose calculator turn mg into syringe units?

It runs two divisions in sequence. First it computes concentration (vial mg ÷ diluent mL) — for the example here that's 5 ÷ 2 = 2.50 mg/mL. Then it divides your dose by that concentration to get volume in mL, and multiplies by 100 to convert volume into U-100 syringe units. The output updates as you type so you can sanity-check before drawing. GHRP-2 raises cortisol and prolactin more than ipamorelin — that's the trade-off for a stronger GH pulse.

Does the GHRP-2 dose calculator know which syringe I'm using?

It assumes a U-100 insulin syringe — the most common type for sub-cutaneous peptide injections. U-100 means 100 units per mL. If you're using a U-40 syringe (rare outside veterinary contexts) the unit count is wrong by a factor of 2.5. Tuberculin syringes read in mL directly, so on those just use the volume figure. GHRP-2 raises cortisol and prolactin more than ipamorelin — that's the trade-off for a stronger GH pulse.

Why does the same GHRP-2 dose pull a different unit count today than last week?

Because either the vial or the diluent volume changed. Concentration depends on both. A 5 mg vial reconstituted with 1 mL is twice as concentrated as the same vial with 2 mL — same dose, half the units. Whenever you open a fresh vial, run the dose math again rather than carrying the prior count over. GHRP-2 raises cortisol and prolactin more than ipamorelin — that's the trade-off for a stronger GH pulse.

What if my GHRP-2 dose lands at fewer than 5 units?

That's the calculator telling you the current vial is too concentrated for the dose you want. Five units on a U-100 syringe is hard to read accurately — the markings get tight. Reconstitute the next vial with more bacteriostatic water (commonly 2 mL instead of 1 mL) so each dose covers a larger, cleaner volume. GHRP-2 raises cortisol and prolactin more than ipamorelin — that's the trade-off for a stronger GH pulse.

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