Vial Guide

Follistatin-344 1 mg vial

How much bacteriostatic water to add to a 1 mg vial of Follistatin-344, the syringe units for each common dose, and how many doses the vial holds.

Water
1 mL
Strength
1 mg/mL
Common dose
100 mcg
Draw
10 units0.10 mL
Doses per vial
10

The short answer

Mixed with 1 mL of bacteriostatic water, a 1 mg vial of Follistatin-344 holds 1 mg/mL. A 100 mcg dose is then 10 units (0.10 mL) on a U-100 insulin syringe, and the vial holds about 10 doses of that size. Taken 1× per day, it lasts about 10 days.

Preclinical. No published study has given follistatin protein to a person. Human testing has been gene therapy instead: a Phase 1 trial injected an AAV1 virus carrying the FS344 gene into the thigh muscles of 15 people with Becker muscular dystrophy or inclusion body myositis, and most walked further afterwards. A separate follistatin-based fusion protein, ACE-083, was injected into muscle in two Phase 2 trials (95 and 63 patients) that were both terminated.
Follistatin-344 page

How much water

The water only sets the strength; the dose and the number of doses in the vial stay the same. Draws are on a U-100 insulin syringe, where 1 unit is 0.01 mL.

Water addedStrengthPer syringe unitDraw for 100 mcg
1 mL1 mg/mL10 mcg10 units (0.10 mL)
2 mL0.5 mg/mL5 mcg20 units (0.20 mL)
3 mL0.3333 mg/mL3.3 mcg30 units (0.30 mL)

Dose chart

Syringe units for each common dose at each water volume. Select a cell to open it in the calculator.

DoseWater added
1 mL2 mL3 mL
50 mcg
60 mcg
75 mcg
100 mcg
150 mcg
200 mcg
250 mcg
300 mcg

Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.

Where the doses come from

  • Community About 100 mcg once daily for 10–30 days is the figure that recurs, but public guides range from 50 to 300 mcg a day and none of them cite a study. No dose of the protein has been tested in people.
  • Trial Gene therapy, not protein: a single set of injections of 2 × 10¹¹ to 6 × 10¹¹ vg/kg per thigh of an AAV1 vector carrying FS344.

Doses are what labels, trials or community reports reference, not recommendations. Follistatin-344’s page has the cycle, side effects, cautions and sources.

Mixing and storage

  1. PrepareLet a refrigerated vial come to room temperature, and wipe both stoppers with an alcohol swab.
  2. Add 1 mLDraw 1 mL of bacteriostatic water and let it run slowly down the inside wall of the vial.
  3. Swirl, don’t shakeSwirl gently until the powder dissolves and the liquid is clear.
  4. Label itWrite the date and the strength, 1 mg/mL, on the vial.

Storage: Powder: −20 °C or colder. Mixed: 2–8 °C for a few weeks.

The reconstitution guide covers each step, and the units page explains syringe markings.

Questions

How much water do I add to a 1 mg vial of follistatin-344?

There’s no single right amount: the water only sets the strength. With 1 mL of bacteriostatic water, a 1 mg vial holds 1 mg/mL. With 2 mL it’s 0.5 mg/mL; with 3 mL it’s 0.3333 mg/mL. Less liquid makes each dose a smaller draw; more makes small doses easier to measure.

How many units is 100 mcg of follistatin-344?

With 1 mL in a 1 mg vial, 100 mcg is 10 units (0.10 mL) on a U-100 insulin syringe. With 2 mL, 20 units (0.20 mL); with 3 mL, 30 units (0.30 mL).

How many doses are in a 1 mg vial of follistatin-344?

About 10 doses of 100 mcg, or 4 of 250 mcg or 3 of 300 mcg. Taken 1× per day at 100 mcg, it lasts about 10 days.

How long does a mixed vial of follistatin-344 keep?

Powder: −20 °C or colder. Mixed: 2–8 °C for a few weeks.

Sources

  • Mendell et al., Phase 1/2a follistatin gene therapy trial for Becker muscular dystrophy (Mol Ther 2015) PMID 25322757
  • Mendell et al., follistatin gene therapy for sporadic inclusion body myositis (Mol Ther 2017) PMID 28279643
  • UniProt P19883, follistatin precursor (344 amino acids)

The math on this page uses the doses and storage on Follistatin-344’s page.

By Vial Guide editorsLast reviewed

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