Follistatin-344 is the 344-amino-acid precursor form of follistatin, a protein that binds myostatin and activin. It has not been tested as an injection in human trials and is not FDA approved.
Also known as: FST-344.
Powder vials are usually labeled 1 mg.
Water and syringe-unit charts by vial size: 1 mg
Here is the math for a 1 mg vial mixed with 1 mL of bacteriostatic water, drawing 100 mcg with a U-100 insulin syringe (1 mL = 100 units).
1 mg ÷ 1 mL = 1 mg/mL100 mcg ÷ 1 mg/mL = 0.1 mL0.1 mL × 100 = 10 units| Amount | Volume | U-100 syringe |
|---|---|---|
| 50 mcg | 0.05 mL | 5 units |
| 100 mcg | 0.1 mL | 10 units |
| 200 mcg | 0.2 mL | 20 units |
Adding more water doesn't change how much Follistatin-344 is in the vial. It only spreads it over more liquid, so each draw is bigger and easier to read.
| Water added | Concentration | Volume | U-100 syringe |
|---|---|---|---|
| 1 mL | 1 mg/mL | 0.1 mL | 10 units |
| 2 mL | 500 mcg/mL | 0.2 mL | 20 units |
| 3 mL | 333.3 mcg/mL | 0.3 mL | 30 units |
| 5 mL | 200 mcg/mL | 0.5 mL | 50 units |
For any other vial size 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.
There are no trials. A 2020 case series described 11 male bodybuilders who developed central serous chorioretinopathy, a fluid build-up under the retina that blurs vision, after injecting whole 1 mg vials of follistatin-344. Anti-doping labs have also published methods for detecting it in black-market products.
We could not find a published human half-life for this compound. Figures quoted online usually come from animal or cell studies, so we do not list one here.