How much bacteriostatic water do you need for a 5,000 IU vial of HCG?

That depends on the concentration you are working to, so it is arithmetic rather than a fixed number. 5,000 IU of HCG in 1 mL of bacteriostatic water gives 5000 IU/mL; in 5 mL it gives 1000 IU/mL; in 10 mL it gives 500 IU/mL. Every volume on this page falls between 1 mL and 10 mL, so one 10 mL vial of bacteriostatic water covers this mix.

What concentration does 5,000 IU of HCG in 5 mL give?

1000 IU/mL. 5000 IU ÷ 5 mL = 1000 IU/mL. On a 1 mL U-100 insulin syringe that is 10 IU in each unit mark and 100 IU in ten marks.

How do you work this out yourself?

Divide the amount of powder printed on the vial by the number of millilitres of water added. The answer is the concentration, in IU per millilitre. To turn that into syringe marks, divide again by 100, because 100 unit marks on a U-100 insulin syringe is exactly 1 mL.

Does this page say what amount to use?

No. This page is dilution arithmetic. It says what is in the vial once powder and water are mixed, and nothing at all about what to do with it afterwards. That belongs to the prescriber or the researcher responsible for the vial.

Bacteriostatic water for 5,000 IU HCG

Mixing a 5,000 IU vial of HCG with 5 mL of bacteriostatic water gives a concentration of 1000 IU/mL, which puts 100 IU in every 10 unit marks on a 1 mL U-100 insulin syringe.

Other water volumes give other concentrations. The full chart is below, with the arithmetic written out so you can check it against your own vial rather than taking this page at its word.

Bac water chart for 5,000 IU HCG

Water volume, resulting concentration and syringe marks for a 5,000 IU vial of HCG
Bacteriostatic water added	Resulting concentration	In 1 unit mark	In 10 unit marks	Whole vial, in unit marks
1 mL	5000 IU/mL	50 IU	500 IU	100 units
2 mL	2500 IU/mL	25 IU	250 IU	200 units
3 mL	~1666.6667 IU/mL	~16.6667 IU	~166.6667 IU	300 units
5 mL	1000 IU/mL	10 IU	100 IU	500 units
10 mL	500 IU/mL	5 IU	50 IU	1000 units

Unit marks are the numbered lines on a 1 mL U-100 insulin syringe: 100 marks = 1 mL, so one mark is 0.01 mL. A value written with a leading “~” has been rounded for display; amounts are shown in IU.

The arithmetic, shown

5000 IU ÷ 5 mL = 1000 IU/mL
1000 IU/mL ÷ 100 unit marks per mL = 10 IU per unit mark

Concentration is the amount of powder divided by the volume of water. The volume of the powder itself is not counted, because at these amounts it is far smaller than the smallest line on the syringe - the same assumption every printed reconstitution chart makes.

What each mark holds at 1000 IU/mL

At 1000 IU/mL - that is 5,000 IU in 5 mL - a 1 mL U-100 insulin syringe reads like this. One unit mark is 0.01 mL, because 100 marks make 1 mL.

What each unit mark on a 1 mL U-100 insulin syringe holds at 1000 IU/mL
Unit mark	Volume	Contains
2	0.02 mL	20 IU
4	0.04 mL	40 IU
5	0.05 mL	50 IU
10	0.1 mL	100 IU
15	0.15 mL	150 IU
20	0.2 mL	200 IU
25	0.25 mL	250 IU
30	0.3 mL	300 IU
40	0.4 mL	400 IU
50	0.5 mL	500 IU
60	0.6 mL	600 IU
80	0.8 mL	800 IU
100	1 mL	1000 IU

How much bacteriostatic water do you need?

You need about 10 mL of bacteriostatic water to mix a 5,000 IU vial of HCG.

Every water volume in these charts is between 1 mL and 10 mL, so a single 10 mL vial of bacteriostatic water covers the largest of them exactly. Bacteriostatic water is sterile water that contains 0.9% benzyl alcohol as a preservative, which is what allows the same vial to be punctured more than once.

See the 10 mL vial

Storage and shelf life

Bacteriostatic water is sterile water that contains 0.9% benzyl alcohol as a preservative. The preservative is the reason a vial can be entered more than once rather than being discarded after a single use. An unopened vial keeps until the expiry date printed on it; once the stopper has been punctured, the discard window printed in the manufacturer’s insert for that vial applies.

Store water and mixed vials as the labelling for each one directs, out of direct light. If the liquid changes colour, goes cloudy, or shows anything floating in it, it goes in the bin rather than in a syringe.

How long bacteriostatic water lasts, in detail

Common questions

How much bacteriostatic water do you need for a 5,000 IU vial of HCG?: That depends on the concentration you are working to, so it is arithmetic rather than a fixed number. 5,000 IU of HCG in 1 mL of bacteriostatic water gives 5000 IU/mL; in 5 mL it gives 1000 IU/mL; in 10 mL it gives 500 IU/mL. Every volume on this page falls between 1 mL and 10 mL, so one 10 mL vial of bacteriostatic water covers this mix.
What concentration does 5,000 IU of HCG in 5 mL give?: 1000 IU/mL. 5000 IU ÷ 5 mL = 1000 IU/mL. On a 1 mL U-100 insulin syringe that is 10 IU in each unit mark and 100 IU in ten marks.
How do you work this out yourself?: Divide the amount of powder printed on the vial by the number of millilitres of water added. The answer is the concentration, in IU per millilitre. To turn that into syringe marks, divide again by 100, because 100 unit marks on a U-100 insulin syringe is exactly 1 mL.
Does this page say what amount to use?: No. This page is dilution arithmetic. It says what is in the vial once powder and water are mixed, and nothing at all about what to do with it afterwards. That belongs to the prescriber or the researcher responsible for the vial.

HCG (human chorionic gonadotropin) is a prescription hormone supplied as a freeze-dried powder, labelled in International Units on most vials and in milligrams on some. It is available on prescription only. This site sells bacteriostatic water. It does not sell HCG.