PeptideCalculations
4 mg/mL · 4,000 mcg/mL · 40 mcg per U-100 unit

20 mg vial + 5 mL bacteriostatic water

A 20 mg vial reconstituted with 5 mL comes to 4 mg/mL. Every unit on a U-100 insulin syringe then carries 40 mcg, so 500 mcg is 12.5 units (0.13 mL) and the vial holds 40 draws of that size.

Units for each amount

20 mg vial + 5 mL = 4 mg/mL (4,000 mcg/mL, 40 mcg per unit on U-100)
DosemLU-100 unitsU-40 unitsDoses per vial
50 mcg0.0131.30.5400
100 mcg0.0252.51200
150 mcg0.0383.81.5133
200 mcg0.0552100
250 mcg0.0636.32.580
300 mcg0.0757.5366
400 mcg0.110450
500 mcg0.1312.5540
750 mcg0.1918.87.526
1 mg0.25251020
1.5 mg0.3837.51513
2 mg0.5502010
2.5 mg0.6362.5258
5 mg1.25125504
10 mg2.52501002

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 unitstable →
5 mL44012.5 units

Same concentration, different vial

These pairs also come to 4 mg/mL, so their unit counts match this page exactly; only the number of draws per vial differs: 2 mg + 0.5 mL, 10 mg + 2.5 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 + 5 mL questions

What concentration is 20 mg in 5 mL?

20 mg divided by 5 mL is 4 mg/mL, which is 4,000 mcg/mL. On a U-100 syringe each unit holds 0.01 mL, so one unit carries 40 mcg.

How many units is 500 mcg from a 20 mg vial with 5 mL?

500 mcg divided by 4,000 mcg/mL is 0.13 mL, which is 12.5 units on a U-100 syringe and 5 units on a U-40 syringe. The vial holds 40 draws of that size.

What if I add 0.5 mL instead of 5 mL to the 20 mg vial?

The mass stays 20 mg. With 0.5 mL the concentration is 40 mg/mL instead of 4 mg/mL, so the same amount per draw needs fewer units: 500 mcg becomes 1.3 units instead of 12.5.

Does a 20 mg vial hold 5 mL?

Not always. Many lyophilized peptide vials are 2 mL or 3 mL glass; 5 mL will not fit in those. Check the vial before choosing this volume, or split the mass across two vials.

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