What's in the vial,
and how much water it needs.

There is no single right volume — it depends on the quantity you want per draw and the syringe you own. The water sets the concentration, and the concentration decides which mark on the barrel your draw lands on. Worked example: a 70 mg Glow vial holds 50 mg of GHK-Cu. Add 2.50 mL and the concentration is 20 mg/mL, so a 2 mg draw is 0.10 mL — exactly 10 units on a U-100 syringe, a printed line you can actually see. Add 3 mL instead and the same 2 mg draw becomes 12 units. Both are correct; one is easier to read. That is why our calculators solve for the water instead of asking you for it.

Divide the peptide mass in the vial by the water volume. A 5 mg vial with 2 mL of bacteriostatic water is 5 ÷ 2 = 2.5 mg/mL, which is the same as 2,500 mcg/mL. For a blend, do it per component: a 70 mg Glow vial contains GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg, so 2.5 mL of water gives 20 mg/mL, 4 mg/mL and 4 mg/mL respectively. Every draw takes all three in that fixed ratio.

On a U-100 syringe the barrel is divided into 100 units per millilitre, so 1 unit = 0.01 mL, 10 units = 0.1 mL and 100 units = a full 1 mL. A U-40 syringe is a different scale — 40 units per millilitre, so one unit is 0.025 mL. Drawing to "20 units" on a U-40 barrel when the number was calculated for U-100 gives two and a half times the intended volume. Check which barrel you have first.

KLOW is an 80 mg blend: GHK-Cu 50 mg, KPV 10 mg, BPC-157 10 mg, TB-500 10 mg. Glow is the same thing without the KPV — 70 mg total: GHK-Cu 50 mg, BPC-157 10 mg, TB-500 10 mg. The K in KLOW is the KPV. Both are community blends rather than branded products, so ratios vary by supplier; these are the figures that were consistent across the sources we checked.

An unopened vial of bacteriostatic water follows its own label — it is shelf-stable and does not need refrigeration before first use. The 0.9% benzyl alcohol in it is what suppresses bacterial growth and makes a multi-dose vial possible in the first place. Once you have punctured either vial, the mixed peptide solution is the thing that needs 2–8°C. We could not source a shelf-life figure for a reconstituted vial in a domestic fridge, so we do not print one — check your product label.

No. The calculators convert units and volumes for figures you supply. Nothing is pre-filled, no option is pre-selected, and the preset buttons are pure arithmetic — each one divides the vial into a round number of equal draws. Where we could not source a figure, the feature that needs it is switched off and the page says why, rather than showing a number we cannot stand behind.

Work out the water volume before you open anything — once it is in, it cannot come back out. Then: let the vial reach room temperature, wipe both stoppers with a fresh alcohol swab and let them air dry, draw the measured volume of bacteriostatic water, and angle the needle so the water runs down the inside glass wall rather than firing onto the powder. Let it dissolve on its own; swirl or roll if anything is left. Never shake it — shaking foams the solution and breaks peptide bonds. Anything containing GHK-Cu turns blue, which is the copper, not contamination.

We do not print a number, and that is deliberate. Reagent suppliers publish stability data for peptides in solution — for example six months at −80°C and one month at −20°C — but those are freezer figures from a laboratory. They say nothing about a vial at 2–8°C in a kitchen fridge, which is what actually happens. The figure repeated across other sites is 28 days; we went looking for its source and could not find one that applies. Keep it cold, keep it dark, and use the shelf life your supplier gives you.

Sealed lyophilized powder tolerates ambient — it ships without cold packs and arrives after days in transit. Once water is in the vial you are asking about solution, which is the least stable state the peptide will ever be in. The risk worth taking seriously is not a room but heat: a parked car, a windowsill, a radiator, hot water, a microwave. Ambient and heat are not the same thing.

A smaller barrel is not a smaller quantity, it is a more readable one. A 0.3 mL U-100 syringe holds 30 units and prints every single unit; a 1 mL holds 100 units and is usually numbered every ten. If your answer lands at 4 units, that is hard to see on a 1 mL barrel and easy on a 0.3 mL. The calculator asks which one you own because the answer changes with it — and it prefers water volumes that put your draw on a line that is actually printed.