Peptide Blend Dosing Math: How Much of Each Peptide Is in a Draw

A single-peptide vial has one number to work out: how many units hold your dose. A blend vial has two or more peptides dissolved in the same water, so they share one concentration ratio. Whatever you draw, each peptide comes along in proportion to how much of it the vial holds.

So you choose the amount of one peptide per draw and the vial sets the rest. If a vial holds five times as much GHK-Cu as BPC-157, every draw has five times as much GHK-Cu as BPC-157, at any water volume. Changing one amount on its own takes separate vials.

The water volume sets how many units a given amount takes, as it does for a single peptide, but adding more or less water leaves the ratio where it was.

GLOW and KLOW are the blends people search for by name, and BPC-157 + TB-500 is a common two-peptide vial. They are usually sold with these amounts, but suppliers differ, so go by the amounts printed on your own vial.

KLOW is GLOW with 10 mg of KPV added. The GHK-Cu stays at 50 mg, so its share of the vial drops from 71.4% to 62.5%, yet each draw still carries five times as much GHK-Cu as BPC-157.

None of these peptides is in an FDA-approved drug. The FDA has raised safety concerns about BPC-157, TB-500, KPV, and injectable GHK-Cu in compounding, citing limited or no human safety data. This blog covers the arithmetic only and makes no claims about what the blends do.

The calculator takes one peptide per vial. You can enter a single peptide from the blend or the blend as a whole, and both give the same number of units.

Method 1: enter one peptide. Use that peptide's mg as the vial size and its amount as the dose. The units are right for the whole liquid, because every peptide sits in the same water. For a GLOW vial mixed with 3 mL, enter a 10 mg vial (the BPC-157), 3 mL of water, and 0.5 mg. The calculator returns 15 units.

Method 2: enter the whole blend. Use the total mg as the vial size and scale the dose up to the whole blend. BPC-157 is 10 of GLOW's 70 mg, so 0.5 mg of BPC-157 comes with 3.5 mg of blend. Enter a 70 mg vial, 3 mL, and 3.5 mg. The calculator again returns 15 units.

In the GLOW example, 15 units carries 0.5 mg × (50 ÷ 10) = 2.5 mg of GHK-Cu and 0.5 mg × (10 ÷ 10) = 0.5 mg of TB-500. The reconstitution math blog works through the first formula step by step.

Ten units on a U-100 syringe is 0.1 mL. Amounts scale with the draw, so 20 units holds twice what 10 units holds and 5 units holds half.

Moving from 2 mL to 3 mL makes every amount per 10 units a third smaller and keeps the ratio. In a 20 mg BPC-157 + TB-500 vial with 2 mL, 10 units holds 500 mcg of each. With 3 mL it holds 333 mcg of each, so the same 500 mcg needs 15 units.

For draws under 30 units, a 30 unit syringe reads more finely than a 100 unit one. The syringe units blog compares barrel sizes, and the BAC water volume blog covers how the water volume moves a dose along the scale.

All the peptides in a blend run out on the same draw, so the vial holds the same number of doses whichever peptide you count by. The quickest way to get it is from the liquid:

A GLOW vial mixed with 3 mL holds 300 units of liquid. At 15 units a draw that is 20 draws, and dividing any peptide's vial amount by its amount per draw gives the same 20 (10 mg ÷ 0.5 mg of BPC-157, or 50 mg ÷ 2.5 mg of GHK-Cu). A little liquid stays behind in the vial, so the last draw can come up short.

The CDC says to discard an opened multi-dose vial within 28 days unless the manufacturer gives another date. Check whether your draws finish inside that window. Twenty draws taken once a day do; taken twice a week, they would need 10 weeks.

The wrong draw usually starts with a blend number in one field and a single-peptide number in the other. With a GLOW vial mixed with 3 mL:

• A 70 mg vial and a 0.5 mg dose, meant as 0.5 mg of BPC-157, gives 2.1 units. That draw holds 71 mcg of BPC-157, a seventh of the intended amount.
• A 10 mg vial (the BPC-157) and a 2.5 mg dose, meant as 2.5 mg of GHK-Cu, gives 75 units. That draw holds 12.5 mg of GHK-Cu, five times the intended amount, along with 2.5 mg each of BPC-157 and TB-500.

A vial marked "70 mg" with no breakdown can't be split by peptide at all. Get the per-peptide amounts from the certificate of analysis or the supplier before working out a draw.