Adding the clinical framing, because it changes how the question reads.

For anyone reconstituting dosing arithmetic peptides: the water-to-powder ratio determines your concentration. Here's my reference:

More water = easier to measure small doses but vial runs out faster. Find the balance that works for your dose.

Following on from anders_CPH — and this may be the naive question:

Did your prescriber agree with that reading, and if not what was their objection?

traveltech_sara said:

For anyone reconstituting dosing arithmetic peptides: the water-to-powder ratio determines your concentration.

dosing arithmetic — critical reminder about tirzepatide dose equivalence across formulations:

Mounjaro KwikPen and compounded tirzepatide are the same molecule but:

• KwikPen is ready to inject, no mixing needed
• Compounded requires reconstitution and proper syringe technique
• Verify your compounded concentration before each injection
• Never assume 1 vial = 1 dose without checking the math

traveltech_sara said:

For anyone reconstituting dosing arithmetic peptides: the water-to-powder ratio determines your concentration.

Quick syringe math for dosing arithmetic dosing: if your vial is reconstituted at 5mg/2mL, that's 2.5mg/mL. For a 0.25mg dose you need 0.1mL = 10 units on an insulin syringe.

I keep a chart on my fridge:

• 0.25mg = 10 units
• 0.5mg = 20 units
• 1.0mg = 40 units
• 1.25mg = 50 units

Always double-check your concentration before drawing up!

Moderator note: the sourcing question belongs in the vendor section and has been split out. Report rather than reply if it drifts again.