Follistatin Dosing Calculator
Follistatin: Activin-binding myostatin inhibitor for muscle growth.
Pre-filled with the most-reported community reconstitution protocol for Follistatin. See how 1 mL and 2 mL of bacteriostatic water change concentration and syringe-draw volume, then adjust the calculator below for your own vial.
Quick answer · Community-reported standard
A 5 mg vial of Follistatin reconstituted with 1 mL of bacteriostatic water yields a concentration of 2.50 mg/mL. At that concentration, a 100 mcg dose of Follistatin equals 4 units on a U-100 insulin syringe (0.040 mL). Follistatin is typically administered once daily via subcutaneous.
Follistatin reconstitution: 1 mL vs 2 mL bac water
Bacteriostatic water volume is flexible. Less water means higher concentration and smaller injection volumes; more water means lower concentration and easier dose precision. Both options below are valid for a 5 mg vial.
| BAC water added | Concentration | Volume per 100 mcg dose | Draw on U-100 syringe (units) |
|---|---|---|---|
| 1 mL | 5.00 mg/mL | 0.020 mL | 2 units |
| 2 mL | 2.50 mg/mL | 0.040 mL | 4 units |
Calculate your Follistatin dose
Alternative Follistatin protocols
Beyond the default above, Follistatin is also reported in the following protocols. Use these as starting points and recalculate with the tool above.
Conservative Low-Dose Protocol
Community- Dose
- 50-100 mcg
- Frequency
- Once daily
- Duration
- 10-14 days
- Route
- Subcutaneous
Lower starting dose for first-time users; single short cycle to assess tolerance
Extended Protocol
Community- Dose
- 100-200 mcg
- Frequency
- Once daily
- Duration
- Up to 30 days
- Route
- Subcutaneous
Longer cycle with higher doses; some users report no additional benefit above 100 mcg
Twice-Weekly Protocol
Community- Dose
- 500 mcg per injection
- Frequency
- Twice weekly
- Duration
- 4-5 weeks (1 mg vial)
- Route
- Subcutaneous
Less frequent dosing with higher per-injection dose; alternative approach for users who prefer fewer injections
Gene therapy - BMD (low dose)
Clinical- Dose
- 3 x 10^11 vg/kg per leg
- Frequency
- Single administration
- Duration
- Intended as one-time treatment
Bilateral intramuscular injection into quadriceps muscles
Gene therapy - BMD (high dose)
Clinical- Dose
- 6 x 10^11 vg/kg per leg
- Frequency
- Single administration
- Duration
- Intended as one-time treatment
Higher dose showed greater functional improvement in Phase 1/2a trial
Follistatin reconstitution & storage
AAV1-FS344 gene therapy vector is supplied as a frozen solution requiring controlled thawing per protocol. Recombinant follistatin protein (research grade) should be reconstituted in sterile buffer per manufacturer specifications.
AAV gene therapy vectors require storage at -80C or below. Recombinant follistatin protein should be stored lyophilized at -20C or below. Reconstituted solutions at 2-8C, use within specified timeframe.
Follistatin dosing FAQ
How much bacteriostatic water should I add to a 5 mg vial of Follistatin?
The community standard is 1 mL of bacteriostatic water for a 5 mg Follistatin vial. That gives a concentration of 2.50 mg/mL, so a 100 mcg dose is 4 units on a U-100 insulin syringe. Adding 1 mL instead doubles the concentration to 5.00 mg/mL and halves the draw to 2 units. Less water = smaller injection volume but harder to measure precisely.
How many syringe units is a 100 mcg dose of Follistatin?
On a standard U-100 insulin syringe, a 100 mcg dose of Follistatin is 4 units when the 5 mg vial is reconstituted with 1 mL of bacteriostatic water (2.50 mg/mL). If you use 1 mL of bac water instead, draw 2 units (5.00 mg/mL).
What is the standard Follistatin dose?
Community-reported protocols for Follistatin typically use 100 mcg once daily via Subcutaneous. 100 mcg is a common starting dose. Short cycles with long breaks; typically one 1 mg vial used over 10-20 days then cycled off for several months
How long does a vial of Follistatin last at 100 mcg once daily?
A 5 mg vial of Follistatin contains roughly 50 doses at 100 mcg per injection. At once daily dosing, that is approximately 50 days (about 7 weeks) of supply per vial. Reconstituted Follistatin should generally be used within 28 days when refrigerated.
Where do you inject Follistatin?
Follistatin is typically injected subcutaneous. Common sites reported in the literature and by users include: Intramuscular (quadriceps, for gene therapy), Subcutaneous (recombinant protein, research), Intravenous (recombinant protein, research). Rotate sites with each injection to reduce localized irritation.
Can I use sterile water instead of bacteriostatic water for Follistatin?
Bacteriostatic water (containing 0.9% benzyl alcohol as a preservative) is strongly preferred for multi-dose vials like Follistatin because it inhibits microbial growth and lets a single vial be used over multiple weeks. Sterile water has no preservative and should generally be reserved for single-use preparations only.
More on Follistatin
Follistatin overview
Mechanism of action, primary uses, and research summary
Follistatin dosing protocols
Full clinical and research-based dosing reference
Follistatin community protocols
Real-world usage patterns from peptide communities
Follistatin side effects
Reported adverse effects and safety considerations
Medical Disclaimer
This website is for educational and informational purposes only. The information provided is not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before using any peptide or supplement.