PeptideCalculations
6.667 mg/mL · 6,667 mcg/mL · 66.67 mcg per U-100 unit

20 mg vial + 3 mL bacteriostatic water

A 20 mg vial reconstituted with 3 mL comes to 6.667 mg/mL. Every unit on a U-100 insulin syringe then carries 66.67 mcg, so 500 mcg is 7.5 units (0.075 mL) and the vial holds 40 draws of that size.

Units for each amount

20 mg vial + 3 mL = 6.667 mg/mL (6,667 mcg/mL, 66.67 mcg per unit on U-100)
DosemLU-100 unitsU-40 unitsDoses per vial
50 mcg0.00750.750.3400
100 mcg0.0151.50.6200
150 mcg0.0232.30.9133
200 mcg0.0331.2100
250 mcg0.0383.81.580
300 mcg0.0454.51.866
400 mcg0.0662.450
500 mcg0.0757.5340
750 mcg0.1111.24.526
1 mg0.1515620
1.5 mg0.2222.5913
2 mg0.3301210
2.5 mg0.3837.5158
5 mg0.7575304
10 mg1.5150602

Same vial, other volumes

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

Watermg/mLmcg per unit500 mcg =
0.5 mL404001.3 unitstable →
1 mL202002.5 unitstable →
1.5 mL13.333133.333.8 unitstable →
2 mL101005 unitstable →
2.5 mL8806.3 unitstable →
3 mL6.66766.677.5 units
5 mL44012.5 unitstable →

Same concentration, different vial

These pairs also come to 6.667 mg/mL, so their unit counts match this page exactly; only the number of draws per vial differs: 10 mg + 1.5 mL.

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

20 mg + 3 mL questions

What concentration is 20 mg in 3 mL?

20 mg divided by 3 mL is 6.667 mg/mL, which is 6,667 mcg/mL. On a U-100 syringe each unit holds 0.01 mL, so one unit carries 66.67 mcg.

How many units is 500 mcg from a 20 mg vial with 3 mL?

500 mcg divided by 6,667 mcg/mL is 0.075 mL, which is 7.5 units on a U-100 syringe and 3 units on a U-40 syringe. The vial holds 40 draws of that size.

What if I add 5 mL instead of 3 mL to the 20 mg vial?

The mass stays 20 mg. With 5 mL the concentration is 4 mg/mL instead of 6.667 mg/mL, so the same amount per draw needs more units: 500 mcg becomes 12.5 units instead of 7.5.

Does a 20 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.

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