PeptideCalculations
0.333 mg/mL · 333 mcg/mL · 3.33 mcg per U-100 unit

1 mg vial + 3 mL bacteriostatic water

A 1 mg vial reconstituted with 3 mL comes to 0.333 mg/mL. Every unit on a U-100 insulin syringe then carries 3.33 mcg, so 100 mcg is 30 units (0.3 mL) and the vial holds 10 draws of that size.

Units for each amount

1 mg vial + 3 mL = 0.333 mg/mL (333 mcg/mL, 3.33 mcg per unit on U-100)
DosemLU-100 unitsU-40 unitsDoses per vial
50 mcg0.1515620
100 mcg0.3301210
150 mcg0.4545186
200 mcg0.660245
250 mcg0.7575304
300 mcg0.990363
400 mcg1.2120482
500 mcg1.5150602
750 mcg2.25225901
1 mg33001201

Same vial, other volumes

The mass does not move. Only the concentration and the unit count do.

Watermg/mLmcg per unit100 mcg =
0.5 mL2205 unitstable →
1 mL11010 unitstable →
1.5 mL0.6676.6715 unitstable →
2 mL0.5520 unitstable →
2.5 mL0.4425 unitstable →
3 mL0.3333.3330 units

Try other numbers

mL
Draw to
—units
— mL on a U-100, 1 mL barrel
Concentration
—mg/mL
— mcg per unit
Doses in the vial
—
of

1 mg + 3 mL questions

What concentration is 1 mg in 3 mL?

1 mg divided by 3 mL is 0.333 mg/mL, which is 333 mcg/mL. On a U-100 syringe each unit holds 0.01 mL, so one unit carries 3.33 mcg.

How many units is 100 mcg from a 1 mg vial with 3 mL?

100 mcg divided by 333 mcg/mL is 0.3 mL, which is 30 units on a U-100 syringe and 12 units on a U-40 syringe. The vial holds 10 draws of that size.

What if I add 0.5 mL instead of 3 mL to the 1 mg vial?

The mass stays 1 mg. With 0.5 mL the concentration is 2 mg/mL instead of 0.333 mg/mL, so the same amount per draw needs fewer units: 100 mcg becomes 5 units instead of 30.

Does a 1 mg vial hold 3 mL?

Usually. Most lyophilized peptide vials are 2 mL or 3 mL glass, and 3 mL fits with room to swirl. Check the vial if it is an unusually small format.

Brands we recommend. We are independent and have no affiliation with any brand: no affiliate links, no referral codes, no paid placements. These are the suppliers whose testing and certificates hold up when we check them.