My new vial is more concentrated — do I draw more or less?

Less. A higher concentration packs the same milligrams into a smaller volume, so you draw fewer units for the identical dose. The calculator gives the exact new number.

Does my dose in mg change when I switch vials?

No — your prescribed dose in milligrams stays the same. Only the units (volume) you draw changes with concentration.

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Vial Transition Dosage Calculator

Switching vial strengths? Keep the same dose, new units.

Dose you want to keepmg

Old vial concentrationmg/mLNew vial concentrationmg/mL

Old vial — you drew

50units

New vial — now draw

25units

Same 5 mg dose — only the volume changes because the new vial is more (or less) concentrated. Double-check the new units against your pharmacy's instructions before your first injection from the new vial.

Switching vial concentrations safely

Pharmacies sometimes dispense a new vial at a different concentration — often more concentrated, so the volume per dose is smaller. Your dose in milligrams doesn't change, but the units you draw do.

The one thing to get right

If you keep drawing the same number of units after switching to a stronger vial, you'll overdose. Enter your dose plus the old and new concentrations, and the calculator shows exactly how many units to draw from the new vial — then confirm against the pharmacy label.

Frequently asked

My new vial is more concentrated — do I draw more or less?: Less. A higher concentration packs the same milligrams into a smaller volume, so you draw fewer units for the identical dose. The calculator gives the exact new number.
Does my dose in mg change when I switch vials?: No — your prescribed dose in milligrams stays the same. Only the units (volume) you draw changes with concentration.

Medical disclaimer. Tiro is a tracking companion, not a medical device, and nothing on this site is medical advice. Always follow the titration schedule and dosing instructions from your prescriber. Never change your dose without talking to them first.