How much BAC water do I add to a 5 mg GHRP-2 vial?

The standard choice is 2.5 mL, which produces 2 mg/mL (20 mcg per unit on a U-100 syringe). A 100 mcg dose is then 5 units and a 200 mcg dose is 10 units. If 5 units feels too small to draw precisely, use 5 mL instead for 1 mg/mL, which makes 100 mcg equal 10 units.

How many units is 100 mcg of GHRP-2?

It depends entirely on concentration. At 2 mg/mL (5 mg vial plus 2.5 mL water) 100 mcg is 5 units. At 1 mg/mL (5 mg vial plus 5 mL water) it is 10 units. At 2.5 mg/mL (5 mg vial plus 2 mL water) it is 4 units. Always recalculate when you change the water volume.

How long does reconstituted GHRP-2 last in the fridge?

Plan on 28 days at 2-8°C when mixed with bacteriostatic water. The 0.9% benzyl alcohol prevents bacterial growth, but the peptide itself slowly degrades regardless, so potency drops beyond that window even if the solution still looks clear. Lyophilized powder in the freezer lasts for years.

Can I use sterile water instead of bacteriostatic water for GHRP-2?

Only if you intend to use the entire vial within about 24 hours. Sterile water has no preservative, so any vial you puncture more than once becomes a contamination risk. Since GHRP-2 is dosed 1 to 3 times daily across many days, bacteriostatic water is the correct choice in nearly every case.

Can I mix GHRP-2 and CJC-1295 in the same vial?

Reconstitute them separately, in their own vials. You can draw both into one syringe right before injecting if the concentrations match, which spares you a second stick, but do not store a pre-mixed syringe or combine the powders. Stability data supports each peptide alone in bacteriostatic water, not a blended solution.

Why is my GHRP-2 solution cloudy after mixing?

Cloudiness after reconstitution points to denatured peptide or contamination, usually from shaking the vial, injecting the water directly onto the powder with force, or a temperature excursion during shipping. There is no way to reverse it. Discard the vial rather than dosing from it.

Does GHRP-2 need to be injected fasted?

Yes for best results. Elevated glucose and insulin blunt the pituitary growth hormone response, so inject first thing in the morning before food and again before sleep at least 2 to 3 hours after your last meal. Wait roughly 20 to 30 minutes after injecting before eating so the pulse is not cut short.

How to Reconstitute GHRP-2: BAC Water Volumes and Syringe Units

GHRP-2 (pralmorelin) arrives as a white lyophilized cake in a sealed vial, most often 5 mg or 10 mg. Typical doses are 100 to 300 mcg, which is 2 to 6 percent of a 5 mg vial, so the BAC water volume you choose decides whether your dose lands on a readable syringe mark or somewhere between two lines.

What You Need Before You Start

GHRP-2 vial, lyophilized (5 mg or 10 mg)
Bacteriostatic water, which is sterile water with 0.9% benzyl alcohol as a preservative
U-100 insulin syringes, 0.3 mL or 0.5 mL, 29 to 31 gauge
A 1 mL or 3 mL syringe with a longer needle for transferring BAC water
Alcohol swabs
A refrigerator set to 2-8°C (36-46°F)

Choosing Your BAC Water Volume

Concentration is simply vial strength divided by water volume. For a 5 mg vial, 2.5 mL of BAC water gives 2 mg/mL, which is 2000 mcg per mL or 20 mcg per unit on a U-100 syringe. A 100 mcg dose is then 5 units and a 200 mcg dose is 10 units.

If you find 5 units too small a volume to draw accurately, use 5 mL of BAC water in the 5 mg vial instead. That gives 1 mg/mL, 10 mcg per unit, so 100 mcg becomes 10 units and 300 mcg becomes 30 units. The tradeoff is that a 0.3 mL syringe cannot hold more than 30 units, and the vial now needs more refrigerator space.

Never inject BAC water straight down onto the powder cake, and never shake the vial. Aim the stream at the inner glass wall so it runs down, then swirl or roll the vial between your fingers until the solution is clear. Mechanical shear from shaking degrades peptide chains.

Common GHRP-2 Concentration Examples

5 mg vial + 2.5 mL BAC water = 2 mg/mL, 20 mcg per unit (100 mcg = 5 units, 200 mcg = 10 units, 300 mcg = 15 units)
5 mg vial + 5 mL BAC water = 1 mg/mL, 10 mcg per unit (100 mcg = 10 units, 300 mcg = 30 units)
10 mg vial + 5 mL BAC water = 2 mg/mL, 20 mcg per unit (100 mcg = 5 units)
10 mg vial + 3 mL BAC water = 3.33 mg/mL, 33.3 mcg per unit (100 mcg = 3 units, harder to read accurately)
5 mg vial + 2 mL BAC water = 2.5 mg/mL, 25 mcg per unit (100 mcg = 4 units, 250 mcg = 10 units)

A 5 mg vial at 2 mg/mL yields 25 doses of 100 mcg, or roughly 12 days at the common 200 mcg twice daily protocol. That matters because reconstituted GHRP-2 has a 28 day practical shelf life, so pick a vial size you can finish inside that window.

Step-by-Step Reconstitution

Let the vial come to room temperature if it was in the freezer. Cold glass encourages condensation inside the stopper.
Wipe both the GHRP-2 stopper and the BAC water stopper with alcohol swabs and let them air dry for about 30 seconds.
Draw your chosen BAC water volume, for example 2.5 mL, into a 3 mL syringe.
Insert the needle into the GHRP-2 vial at roughly a 45 degree angle so the stream hits the glass wall.
Release the plunger slowly and let the vacuum in the vial pull the water in. Push gently only if the vacuum stalls.
Withdraw the needle, then swirl or roll the vial for 30 to 60 seconds. Full dissolution usually takes under a minute.
Hold the vial to a light source. The solution must be clear and colorless with no floating particles or fibers.
Label the vial with the reconstitution date, the mg strength, and the resulting mg/mL concentration.
Refrigerate at 2-8°C immediately.

Drawing an Accurate Dose

At 2 mg/mL a 100 mcg dose is only 0.05 mL, which is 5 units. On a 0.3 mL U-100 syringe each unit mark is about 3 mm apart, so 5 units is readable, but there is no room for sloppiness. Draw slightly past your target, tap out air bubbles, then push back down to the exact mark with the needle still in the vial.

If you are unsure how the unit scale maps to your concentration, the insulin syringe reading guide walks through the markings line by line. To skip the arithmetic entirely, enter your vial size, water volume, and target dose into the GHRP-2 calculator and it returns the exact unit count with a live syringe diagram.

GHRP-2 CalculatorPre-loaded with a 5 mg vial, 2.5 mL BAC water, and a 100 mcg dose.

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General Peptide CalculatorEnter any vial size and water volume for a custom unit calculation.

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Reading an Insulin SyringeHow U-100 unit marks translate into mL and mcg.

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Storage and Shelf Life

Lyophilized GHRP-2 kept in the freezer at -20°C, sealed and dry, stays stable for years. Once reconstituted with bacteriostatic water, refrigerate at 2-8°C and plan to use the vial within 28 days. The benzyl alcohol in BAC water suppresses bacterial growth but does nothing to stop chemical degradation of the peptide, so the 28 day figure is about potency as much as sterility.

Do not freeze a reconstituted vial. Ice crystal formation and the freeze thaw cycle physically fracture peptide chains, and the loss is invisible: the solution can look perfectly clear while a meaningful fraction of the peptide is no longer active. Keep the vial in the body of the refrigerator rather than the door, where temperature swings are largest, and keep it out of direct light.

For a fuller breakdown of freezer versus refrigerator handling, travel, and shipping without ice packs, see the peptide storage guide.

Reconstituting GHRP-2 for a Stack

GHRP-2 is usually run alongside a GHRH analog such as CJC-1295 without DAC or sermorelin. The GHRH analog loads the somatotroph cells while GHRP-2 triggers release and suppresses somatostatin, so the combined pulse is larger than either compound alone.

Reconstitute each peptide in its own vial. Do not mix powders. If you want a single injection, match the concentrations (for example both at 2 mg/mL) so you can draw 5 units of each into the same syringe immediately before injecting. Drawing both compounds into one barrel is fine for a same-session injection, but never store a mixed syringe: the stability data behind the 28 day window applies to each peptide in its own vial, not to a combined solution.

Troubleshooting

Powder will not dissolve after a minute of swirling: let it sit at room temperature for 5 to 10 minutes and swirl again. GHRP-2 is highly water soluble, so persistent undissolved material suggests a product quality problem.
Solution is cloudy or has visible strands: discard the vial. Cloudiness means denaturation or contamination, and neither is salvageable.
No vacuum when the needle enters: the stopper seal may have failed. Treat sterility as compromised.
The cake looks like it shrank or shifted before mixing: cosmetic movement of the lyophilized cake during shipping is normal and does not affect potency.
Yellow tint after a few weeks in the refrigerator: this is oxidation. Discard rather than dose.

Related Growth Hormone Secretagogues

The same reconstitution math applies to the other GHRPs, only the target dose changes. Ipamorelin is dosed at 100 to 300 mcg with essentially no cortisol, prolactin, or appetite effect. GHRP-6 runs at 100 to 300 mcg with the strongest hunger response of the three. Hexarelin uses lower doses of 100 to 200 mcg and desensitizes fastest.

Ipamorelin and CJC-1295 Stack GuideDosing, timing, and how to combine a GHRP with a GHRH analog.

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Sermorelin Dosing GuideThe GHRH side of the stack, with titration and timing.

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Peptide Injection Sites GuideSubcutaneous site selection and rotation for daily injections.

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Peptide Storage GuideFreezer, refrigerator, travel, and shelf life rules.

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