Protoche

GLP-1 calculator

Compounded GLP-1 calculator

A compounded vial is a concentration, not a metered pen. Enter vial mg, BAC mL, and dose to see the units to draw.

U-100 math · private · no signup

Draw 200 units · 2 mL
Concentration
2.5 mg/mL · 2500 mcg/mL
Correct draw
200 u · 2 mL
Vial yield
1 doses
Draw status
split required
0102030405060708090100exceeds one U-100 syringe — split the draw

The plunger marks the correct draw for your target — even in check mode, so the picture never reinforces a wrong planned draw.

Math runs in your browser. No account, nothing sent anywhere, nothing stored. Reconstitution numbers do not transfer between vials — these are computed from the vial and volume you entered.

Need label verification, BUD and refill timing, and a concentration sanity-check? The GLP-1 vial reality check takes it from here.

What it checks

  • mg, mL, units translation
  • Concentration and BUD
  • Titration step in units
  • GLP-class stop flags

When it helps

  • Your vial lists concentration, not dose
  • You switched pharmacy or program
  • You are mapping a pen schedule to a vial

What it won’t verify

  • Pharmacy compounding quality
  • Salt or form equivalence
  • Pharmacy licensing status

Reading a COA for a vial? Use the manual COA literacy checklist. No upload, no verification, no pass mark.

The mistake it prevents

A compounded vial is not the FDA-approved brand product, and it is not the pen. The pen meters each dose while the label and prescriber set the titration. A compounded multi-dose vial only gives you a concentration, and that concentration can differ by pharmacy and by batch.

Reusing a semaglutide-style pen titration (0.25, then 0.5, then 1 mg) on a compounded vial copies the milligrams but not the draw. The units that deliver 0.25 mg depend entirely on the concentration in your vial.

See the math

Compounded vial: 10 mg + 2 mL5 mg/mL
A 0.25 mg start dose5 units
New pharmacy at 2.5 mg/mL10 units
Same 0.25 mg, different vial2x the draw

The brand pen hides this by metering the dose for you. A vial does not. The same 0.25 mg is a different draw at each pharmacy concentration, so pen clicks and unit directions do not transfer until you recompute them.

Before you switch or draw

  • Read mg/mL, BUD, and lot from the compounded label
  • Do not reuse pen clicks or unit directions without recomputing them
  • Recompute units every time the pharmacy or batch changes
  • GLP-class stop rules apply, including pancreatitis and gallbladder; the checker screens more

Protoche is a checker, not a prescriber. Use it to catch math, source-lane, and stop-rule problems before you make a decision with a licensed clinician or before you decide to pause.