How do you calculate units for a blend vial?

Add the masses of all compounds to get total vial strength. Divide by the bac water volume to get total concentration. Divide your total target dose by total concentration, then multiply by 100 for U100 units. This is valid when your dose ratio matches the vial mass ratio. When ratios differ, calculate each compound separately.

Can BPC-157 and TB-500 be mixed in the same vial?

Yes — they are generally considered compatible in solution. When blending, calculate each compound's concentration independently (each compound's mass ÷ total bac water volume). The blend only delivers your intended dose ratio if the vial mass ratio matches the target dose ratio. If you want unequal doses, adjust the vial masses accordingly.

Can CJC-1295 and Ipamorelin be mixed in the same vial?

Yes — CJC-1295/Ipamorelin blends are the standard setup for this combination protocol. Most compounding pharmacies supply them pre-blended. Standard ratios are 1:1 (5 mg each) for equal-dose protocols (200 mcg + 200 mcg or 300 mcg + 300 mcg).

Does mixing two peptides in one vial affect their stability?

In general, peptides in the same class (both GH-axis compounds, both repair peptides) are considered compatible in solution, but formal stability data for specific combinations is limited. Compounding pharmacies that supply blend vials have validated their formulations. For DIY blending, the conservative approach is to use separate vials unless the combination is well-established in practice.

Reconstitution Math

Blend Vial Math: Calculating Units When Two Peptides Share a Vial

How to calculate units for blend vials when two peptides share bacteriostatic water, what goes wrong when dose ratio doesn't match vial mass ratio, and worked examples for CJC-1295/Ipamorelin and BPC-157/TB-500 blends.

Protocol Editor·April 25, 2026

Informational only. Not medical advice. Consult a licensed healthcare provider before starting, changing, or stopping any protocol.

What a blend vial is

A blend vial contains two or more peptides reconstituted together in the same vial. Rather than maintaining separate vials and drawing from each, you draw a single volume that delivers your intended dose of each compound simultaneously.

Blend vials are common for:

BPC-157 + TB-500 (same dosing schedule, co-injectable)
CJC-1295 (no DAC) + Ipamorelin (designed to be co-injected)
Any two compounds with compatible stability in solution and matching injection timing

Not all compound pairs are suitable for blending. Compounds with different dosing schedules (daily BPC-157 vs. twice-weekly TB-500) require careful calculation to ensure the blend ratio matches the intended dose of each component.

The core math

In a blend vial, both compounds share the same bac water volume. Each compound's concentration is calculated independently based on its own mass:

Concentration of compound A (mcg/mL) = Mass of A (mcg) ÷ Total bac water (mL)

To find the volume to draw for a dose of A:

Volume (mL) = Target dose of A (mcg) ÷ Concentration of A (mcg/mL)

Because both compounds are in the same solution, drawing the volume for compound A automatically delivers compound B at its proportional concentration. This only works correctly if the dose ratio you want matches the mass ratio in the vial.

Example 1: CJC-1295 / Ipamorelin standard blend

Setup: 5 mg CJC-1295 (no DAC) + 5 mg Ipamorelin in one vial + 2 mL bac water.

CJC-1295 concentration: 5,000 mcg ÷ 2 mL = 2,500 mcg/mL
Ipamorelin concentration: 5,000 mcg ÷ 2 mL = 2,500 mcg/mL
Total concentration: 5,000 mcg/mL

Target dose: 200 mcg CJC-1295 + 200 mcg Ipamorelin = 400 mcg total.

Volume: 400 ÷ 5,000 = 0.08 mL
Units (U100): 0.08 × 100 = 8 units

Drawing 8 units delivers exactly 200 mcg of each compound because they're in a 1:1 ratio and you're targeting equal doses.

Example 2: BPC-157 / TB-500 blend with different target doses

Setup: 5 mg BPC-157 + 5 mg TB-500 in one vial + 2 mL bac water.

BPC-157 concentration: 2,500 mcg/mL
TB-500 concentration: 2,500 mcg/mL
Total concentration: 5,000 mcg/mL

Target dose: 250 mcg BPC-157 + 500 mcg TB-500 = 750 mcg total.

Problem: the vial has equal concentrations but you want a 1:2 dose ratio. Drawing the volume for 750 mcg total (15 units) delivers 375 mcg of each — not 250 + 500.

Solution: Draw based on one compound as the reference:

For 500 mcg TB-500 at 2,500 mcg/mL: 500 ÷ 2,500 = 0.20 mL = 20 units
That same draw delivers: 20 units × 2,500 mcg/mL ÷ 100 = 500 mcg TB-500 ✓
And: 20 units × 2,500 mcg/mL ÷ 100 = 500 mcg BPC-157 ✗ (wanted 250)

The 1:1 vial ratio doesn't match the 1:2 dose ratio. For this case, you have two options:

Adjust the vial ratio: Use 2.5 mg BPC-157 + 5 mg TB-500 in the vial. Now BPC-157 concentration = 1,250 mcg/mL, TB-500 = 2,500 mcg/mL. Drawing for 750 mcg total: 750 ÷ 3,750 × 100 = 20 units → delivers 250 mcg BPC + 500 mcg TB ✓
Use separate vials: Keep BPC-157 and TB-500 in separate vials, draw and combine in the syringe, or inject sequentially.

Example 3: Equal-mass blend, equal doses (the clean case)

The math is simplest when vial mass ratio = intended dose ratio. For CJC-1295/Ipamorelin at 200 mcg + 200 mcg (1:1 dose ratio) from a 5 mg + 5 mg vial (1:1 mass):

Bac water added	Total concentration	200 + 200 mcg dose	Units (U100)
1 mL	10,000 mcg/mL	400 mcg total	4 units
2 mL	5,000 mcg/mL	400 mcg total	8 units
3 mL	3,333 mcg/mL	400 mcg total	12 units

Using the calculator for blend vials

The reconstitution calculator handles blend vials by treating the combined mass as the total vial strength. For a 5 mg + 5 mg blend (10 mg total) + 2 mL bac water targeting 400 mcg total dose: enter vial strength = 10 mg, bac water = 2 mL, target dose = 400 mcg. The result (8 units) delivers the correct volume for both compounds — provided the dose ratio matches the vial mass ratio.

When dose ratios don't match vial ratios, use the calculator for each compound separately and verify the combined draw delivers the intended individual doses.

Frequently asked questions

How do you calculate units for a blend vial?: Add the masses of all compounds to get total vial strength. Divide by the bac water volume to get total concentration. Divide your total target dose by total concentration, then multiply by 100 for U100 units. This is valid when your dose ratio matches the vial mass ratio. When ratios differ, calculate each compound separately.
Can BPC-157 and TB-500 be mixed in the same vial?: Yes — they are generally considered compatible in solution. When blending, calculate each compound's concentration independently (each compound's mass ÷ total bac water volume). The blend only delivers your intended dose ratio if the vial mass ratio matches the target dose ratio. If you want unequal doses, adjust the vial masses accordingly.
Can CJC-1295 and Ipamorelin be mixed in the same vial?: Yes — CJC-1295/Ipamorelin blends are the standard setup for this combination protocol. Most compounding pharmacies supply them pre-blended. Standard ratios are 1:1 (5 mg each) for equal-dose protocols (200 mcg + 200 mcg or 300 mcg + 300 mcg).
Does mixing two peptides in one vial affect their stability?: In general, peptides in the same class (both GH-axis compounds, both repair peptides) are considered compatible in solution, but formal stability data for specific combinations is limited. Compounding pharmacies that supply blend vials have validated their formulations. For DIY blending, the conservative approach is to use separate vials unless the combination is well-established in practice.

Sources

United States Pharmacopeia. <797> Pharmaceutical Compounding — Sterile Preparations. Compatibility and stability guidance. USP 43–NF 38.
Sikiric P, et al. Stable gastric pentadecapeptide BPC 157. Curr Pharm Des. 2011;17(16):1612-32.

Stop doing this math by hand.

My Pep Calc runs reconstitution, dose tracking, site rotation, and half-life curves for your whole stack — not just one compound.

See the Founders offer →