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[Peptide · Semax · 5 mg vial]

Semax 5 mg reconstitution: how much water and how many units

Water volume chart · Syringe units · Draws per vial

Short answer: 2 mL of bacteriostatic water in a 5 mg semax vial makes 2.5 mg/mL. On a U-100 insulin syringe (1 mL = 100 units), every 10 units then holds 250 mcg. More water gives a weaker solution and a bigger draw for the same amount; the amount in the vial stays 5 mg.

Water volume chart for a 5 mg vial

5 mg semax vial, U-100 insulin syringe.
Water addedConcentrationPer 10 unitsPer 1 unit
1 mL5 mg/mL500 mcg50 mcg
2 mL2.5 mg/mL250 mcg25 mcg
3 mL1.67 mg/mL166.667 mcg16.667 mcg
5 mL1 mg/mL100 mcg10 mcg

Syringe units by amount

The amounts below are examples to show the conversion, not doses. How much to take is a decision for you and your prescriber.

Units on a U-100 syringe from a 5 mg vial.
Water added125 mcg250 mcg500 mcg
1 mL2.5 units5 units10 units
2 mL5 units10 units20 units
3 mL7.5 units15 units30 units
5 mL12.5 units25 units50 units

A 5 mg vial holds 40 draws of 125 mcg, 20 draws of 250 mcg, 10 draws of 500 mcg, no matter how much water you add.

The math

  1. Concentration. 5 mg ÷ 2 mL = 2.5 mg/mL
  2. Volume to draw. amount ÷ 2.5 mg/mL = mL
  3. Syringe units. mL × 100 = units

For a different water volume or amount, the free peptide reconstitution calculator works backwards from the amount you want and suggests a water volume that lands on a clean syringe mark.

Other semax vial sizes

Semax 10 mg

Half-life, time to peak and sources are on the main Semax guide.

Frequently asked questions

How much bacteriostatic water do I add to a 5 mg semax vial?+
There is no single right amount. More water makes each draw bigger and easier to measure; less water keeps the volume small. With 2 mL, a 5 mg vial is 2.5 mg/mL, so every 10 units on a U-100 insulin syringe holds 250 mcg. With 1 mL it is 5 mg/mL (500 mcg per 10 units). With 3 mL it is 1.67 mg/mL (166.667 mcg per 10 units). With 5 mL it is 1 mg/mL (100 mcg per 10 units).
How many units is 250 mcg of semax from a 5 mg vial?+
With 2 mL of water the vial is 2.5 mg/mL, so 250 mcg is 0.1 mL, or 10 units on a U-100 syringe. With a different water volume the units change but the amount does not. The amount is an example for the math, not a recommendation.
How many 250 mcg draws are in a 5 mg semax vial?+
20 (5 mg ÷ 250 mcg), whatever volume of water you add. In practice a little is lost to the syringe dead space and the last drops in the vial.

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