NurseAsh_DET said:

Compounding pharmacy dose accuracy check for dosing arithmetic: I always verify my first dose from a new vial by weighing it on a milligram scale.

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.

amsterdam_pete said:

The arithmetic is right and one caveat matters: a U-40 syringe changes the markings, not the volumes.

This is exactly what I could not find anywhere else. Taking it to my next appointment.

NurseAsh_DET said:

Compounding pharmacy dose accuracy check for dosing arithmetic: I always verify my first dose from a new vial by weighing it on a milligram scale.

Peptide calculator app recommendation for dosing arithmetic: I use PeptideCalc to calculate reconstitution volumes and injection doses. Eliminates math errors completely.

Input: vial size (mg), desired concentration (mg/mL), prescribed dose (mg)
Output: BAC water volume (mL), injection volume (units on insulin syringe)

A math error with injectable medication can mean underdosing or overdosing. Use a calculator every time until the math becomes second nature.

james_edin said:

Two of us with identical vials and identical diluent arrived at different unit counts, which means one of us has a conceptual error rather than a…

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.