How Much BAC Water for Peptides: Chart and Examples

BAC water alters the concentration of a peptide vial and the number of units drawn but not the dose. A 10 mg vial mixed with 1 mL of BAC water results in 10 mg/mL. This configuration places 100 mcg in every unit on a U-100 insulin syringe.

If the same vial is mixed with 2 mL, the concentration is 5 mg/mL, or 50 mcg per unit. The appropriate volume puts your dose on a clearly readable mark.

A draw under 3 units becomes difficult to measure accurately, so add more water. If the draw exceeds the syringe's barrel, a reduction in water is required. The peptide calculator calculates the draw for any vial, water volume, and dose.

The peptide in a vial remains a fixed quantity of powder, with BAC water serving only to dilute it. Increasing the water volume weakens the solution, causing the same dose to occupy a larger syringe volume. Less water concentrates the solution, reducing the volume required for the same dose.

The total number of doses in the vial remains constant no matter the water volume. This count depends only on the vial size and dose. In this site's data, 2 mL is the default BAC water in 71 of the 89 dedicated calculators, and 1 mL in 12.

These defaults are only starting points and are adjustable. The calculations for each setup fit in two lines for a U-100 syringe.

mcg per mL = vial mg × 1,000 ÷ water mL

Units to draw = dose mcg ÷ mcg per mL × 100 (U-100 syringe)

Worked check: a 5 mg vial in 2 mL is 2,500 mcg per mL, so a 250 mcg dose is 10 units.

This peptide reconstitution chart includes eight vial sizes, ranging from 2 mg to 100 mg, and four BAC water volumes. The first table displays concentration in mg/mL. The second table provides the mcg per unit on a U-100 syringe, which is essential for reading the barrel.

Concentration in mg/mL by vial size (rows) and BAC water added (columns):

Worked examples, not dose recommendations. Values are rounded to one decimal.

mcg per unit on a U-100 syringe by vial size (rows) and BAC water added (columns):

Worked examples, not dose recommendations. Values are rounded to one decimal.

For determining the mcg in 10 units (0.1 mL), multiply any cell in the second table by 10. The printable reconstitution card handles the reverse calculation, with common dose columns already converted to units.

For a 10 mg vial, the addition of BAC water determines the syringe scale. At 1 mL, the concentration is 10 mg/mL, or 100 mcg per unit. At 2 mL, the concentration becomes 5 mg/mL, or 50 mcg per unit. At 3 mL, it shifts to 3.3 mg/mL, or 33.3 mcg per unit.

Smaller doses are more easily read at higher volumes as each unit conveys less peptide. Larger doses align better with the barrel at lower volumes. Regardless of the choice, the total peptide in the vial remains unchanged.

A 20 mg vial combined with 1 mL of BAC water results in 20 mg/mL, with each unit containing 200 mcg. Using 2 mL yields 10 mg/mL (100 mcg per unit). With 5 mL, it results in 4 mg/mL (40 mcg per unit).

Higher water volumes make small doses easier to read with a vial of this size. Before adding 5 mL, verify that the vial can accommodate that volume. If not, use a smaller volume and expect a reduced syringe draw.

The default setting in the tirzepatide calculator is 2 mL of BAC water, with preset vial sizes including 5, 10, and 15 mg. A 10 mg tirzepatide vial with 2 mL yields 5 mg/mL. At this concentration, 50 units on a U-100 syringe contain 2.5 mg and 100 units contain 5 mg.

These calculations are purely numerical and not indicative of a dosing regimen. The tirzepatide calculator outlines the dose tiers and their respective draws. Any changes in vial or water volume mean recalculating for each new vial.

The default for the GHK-Cu calculator is 2 mL of BAC water. Vial presets include 5 and 50 mg. Thus, 100 mg is not a preset and requires selecting Other in the vial field and entering 100.

A 100 mg GHK-Cu vial with 2 mL results in 50 mg/mL, or 500 mcg per unit. Using 5 mL provides 20 mg/mL or 200 mcg per unit, distributing the dose over more marks.

The mixing process is consistent with other vials and is detailed in how to reconstitute peptides. The GHK-Cu calculator converts any dose to units.

Growth hormone vials are labeled in IU rather than mg. The WHO standard defines 1 mg as 3 IU, the factor used by the HGH calculator. A 10 IU vial with 1 mL of BAC water holds 10 IU per mL, making 10 units equivalent to 1 IU. The HGH calculator runs the same math from its 1 mL default and takes the vial size in mg.

One mL of BAC water corresponds to 100 units on any U-100 insulin syringe, since the U-100 scale marks 100 units per mL. A 0.5mL U-100 barrel holds 50 units and a 0.3mL U-100 barrel holds 30, both counting 100 units per mL.

A U-40 syringe instead marks 40 units per mL, so the same number on its barrel holds 2.5 times the volume. Insulin syringe units provides complete conversion details.

Begin with the dose, not the water. Enter the dose into the calculator using the default volume and evaluate the draw. If under 3 units, add water. If it exceeds the barrel, decrease the water.

The reverse calculator checks a draw in reverse, from syringe units to mcg. For further information on the number of doses a vial provides and its duration, refer to how long a peptide vial lasts.