Vial Guide

GHRP-2 10 mg vial

How much bacteriostatic water to add to a 10 mg vial of GHRP-2, the syringe units for each common dose, and how many doses the vial holds.

Water
5 mL
Strength
2 mg/mL
Common dose
100 mcg
Draw
5 units0.05 mL
Doses per vial
100

The short answer

Mixed with 5 mL of bacteriostatic water, a 10 mg vial of GHRP-2 holds 2 mg/mL. A 100 mcg dose is then 5 units (0.05 mL) on a U-100 insulin syringe, and the vial holds about 100 doses of that size. Taken 2× per day, it lasts about 7.1 weeks.

Approved drug. Approved in Japan since 2004 (GHRP Kaken 100) only as a single IV dose to test for growth hormone deficiency; the test was validated against the insulin tolerance test in 135 people. A 48-week placebo-controlled trial of a GHRP-2 nasal spray in 126 children with GH deficiency found no growth benefit, and it has never been approved as a treatment.
GHRP-2 page

How much water

The water only sets the strength; the dose and the number of doses in the vial stay the same. Draws are on a U-100 insulin syringe, where 1 unit is 0.01 mL.

Water addedStrengthPer syringe unitDraw for 100 mcg
2.5 mL4 mg/mL40 mcg2.5 units (0.025 mL)
3 mL3.333 mg/mL33.3 mcg3 units (0.03 mL)
5 mL2 mg/mL20 mcg5 units (0.05 mL)

Dose chart

Syringe units for each common dose at each water volume. Select a cell to open it in the calculator.

DoseWater added
2.5 mL3 mL5 mL
100 mcg
150 mcg
200 mcg
250 mcg
300 mcg

Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Where the doses come from

  • Label Diagnostic test only: one 100 mcg IV dose after an overnight fast (children aged 4–17: 2 mcg/kg, up to 100 mcg). Not a treatment regimen.
  • Trial Nasal spray, 50–200 mcg (by body weight) twice daily for 48 weeks in children with GH deficiency; no growth benefit over placebo.
  • Community 100 mcg per injection (often framed as about 1 mcg/kg), 1–3× daily on an empty stomach; some guides go up to 200–300 mcg.

Doses are what labels, trials or community reports reference, not recommendations. GHRP-2’s page has the cycle, side effects, cautions and sources.

Mixing and storage

  1. PrepareLet a refrigerated vial come to room temperature, and wipe both stoppers with an alcohol swab.
  2. Add 5 mLDraw 5 mL of bacteriostatic water and let it run slowly down the inside wall of the vial.
  3. Swirl, don’t shakeSwirl gently until the powder dissolves and the liquid is clear.
  4. Label itWrite the date and the strength, 2 mg/mL, on the vial.

Storage: Powder: frozen or refrigerated. Mixed: 2–8 °C, use within about 3–4 weeks.

The reconstitution guide covers each step, and the units page explains syringe markings.

Questions

How much water do I add to a 10 mg vial of GHRP-2?

There’s no single right amount: the water only sets the strength. With 5 mL of bacteriostatic water, a 10 mg vial holds 2 mg/mL. With 2.5 mL it’s 4 mg/mL; with 3 mL it’s 3.333 mg/mL. Less liquid makes each dose a smaller draw; more makes small doses easier to measure.

How many units is 100 mcg of GHRP-2?

With 5 mL in a 10 mg vial, 100 mcg is 5 units (0.05 mL) on a U-100 insulin syringe. With 2.5 mL, 2.5 units (0.025 mL); with 3 mL, 3 units (0.03 mL).

How many doses are in a 10 mg vial of GHRP-2?

About 100 doses of 100 mcg, or 40 of 250 mcg or 33 of 300 mcg. Taken 2× per day at 100 mcg, it lasts about 7.1 weeks.

How long does a mixed vial of GHRP-2 keep?

Powder: frozen or refrigerated. Mixed: 2–8 °C, use within about 3–4 weeks.

Other vial sizes

Sources

  • GHRP Kaken 100 (pralmorelin hydrochloride) package insert, Japan, rev. July 2025
  • Chihara et al., GHRP-2 test for adult GH deficiency (Eur J Endocrinol 2007) PMID 17609397
  • Tanaka et al., GHRP-2 nasal spray in children with GH deficiency (Clin Pediatr Endocrinol 2014) PMID 25374440
  • FDA: bulk drug substances for compounding that may present significant safety risks (GHRP-2), April 2026

The math on this page uses the doses and storage on GHRP-2’s page.