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Performance & Musclepreclinical

Follistatin-344

FS-344
Performance & Muscle
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Category
Performance & Muscle
Evidence grade
D
PubMed records
12
Female-tagged
4
Sex-analysis
0
CAS
—
D
Evidence grade D, Preclinical / animal evidence only across 12 indexed studies. No human trial data. How grades work →
Female evidence: None
Follistatin-344: of 12 PubMed records, 4 are tagged as including female subjects and 0 carry a sex-analysis tag.Counts reflect PubMed records as of 2026-07-21. “Female” uses the Female MeSH filter and “sex-analysis” the Sex Factors MeSH filter, automated proxies pending manual study-level review. Methodology →

Overview

Follistatin 344 is a synthetic form of follistatin, an activin-binding glycoprotein that occurs naturally in several isoforms. This particular isoform is used as a tool compound in muscle-development and growth-regulation research, where a defined, reproducible follistatin sequence is useful for probing protein interactions in the laboratory.

In preclinical and in-vitro systems, follistatin 344 has been studied as an antagonist of myostatin (also called GDF-8), a negative regulator of skeletal-muscle mass. Researchers examining the myostatin and activin signaling axis have used follistatin isoforms as research materials to characterize how sequestering these ligands relates to models of muscle-fiber growth and TGF-beta superfamily signaling.

What makes follistatin 344 a useful entry for a muscle-research catalog is its well-defined role within a specific, extensively mapped regulatory pathway. Whether these mechanisms translate to female physiology remains an open research question; our evidence review tracks how many of the underlying studies included women. Supplied for in-vitro and laboratory research only.

Summary

Follistatin-344 is an isoform of the natural myostatin/activin antagonist follistatin, studied preclinically (including via gene therapy) for muscle growth. There are no controlled human efficacy trials of the peptide and no female-specific data.

Evidence in women

Menstrual cycle
Unstudied
No studies examine menstrual cycle interactions.
Pregnancy & lactation
Unstudied
Follistatin has reproductive roles, but no safety data exist for it as an administered compound in pregnancy or lactation.
Hormonal interactions
Unstudied
No controlled data on reproductive- or thyroid-hormone interactions.
Perimenopause & menopause
Unstudied
No perimenopausal or menopausal data.
Sex differences
Unstudied
Preclinical muscle studies did not report sex-stratified outcomes.

Mechanism

Binds and neutralizes myostatin and activins, relieving their restraint on muscle growth.

Reported dosing & routes

◐

We don't give dosing or medical advice. The figures below describe what was used in published research, not a recommendation. Decide with your clinician.

Reported range (literature)No established human dose; muscle effects shown in preclinical and gene-therapy models.
Routessubcutaneous
Female-specific dosingNot established

Contraindications: insufficient data to characterize

Side effects

Reported in the research literature. Sex-specific incidence has not been separately analysed in the available records.

insufficient human data to characterize

Follistatin-344 reconstitution calculator

Enter this vial's amount, the bacteriostatic water you add, and a target amount to get the concentration and the U-100 syringe units to draw. Handling arithmetic for research use, not a dose recommendation.

Reconstitution

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Draw for Follistatin-344

5
units on a U-100 insulin syringe
020406080100
U-100 insulin syringe — 1 mL = 100 units
That's 0.05 mL drawn to the 5-unit mark.
Concentration5 mg/mL (5,000 mcg/mL)
Volume to draw0.05 mL
Doses per vial40

Reference chart at 5 mg/mL

Target amountVolume (mL)U-100 units
100 mcg0.02 mL2
250 mcg0.05 mL5
500 mcg0.1 mL10
750 mcg0.15 mL15
1000 mcg0.2 mL20

Research-use arithmetic only. This tool converts a vial amount, diluent volume, and a target amount into a concentration and syringe draw for laboratory handling. It is not dosing guidance, a recommendation, or a claim of safety or efficacy, and it does not account for overfill, dead space, or peptide purity. Nothing here is medical advice. “U-100” means 100 units = 1 mL; confirm your syringe graduation before measuring. See the reconstitution & storage handbook for handling detail.

Frequently asked questions

Answers drawn only from Follistatin-344's research facts and, where reviewed, its sex-disaggregated evidence. Nothing here is medical advice, dosing, or a claim of safety or efficacy.

What is Follistatin-344?

Follistatin-344, also known as FS-344, is a research compound in our performance muscle category. Follistatin-344 is an isoform of the natural myostatin/activin antagonist follistatin, studied preclinically (including via gene therapy) for muscle growth.

Is Follistatin-344 studied in women?

Follistatin-344: of 12 PubMed records, 4 are tagged as including female subjects and 0 carry a sex-analysis tag. We grade this none: no PubMed record for Follistatin-344 is tagged as including female subjects, so its effects in women are effectively unstudied. That blank is the finding, not a safety signal, and we do not fill it with guesses.

Has Follistatin-344 been studied during pregnancy or breastfeeding?

Unstudied. Follistatin has reproductive roles, but no safety data exist for it as an administered compound in pregnancy or lactation. This is not a safety clearance or a recommendation. Vera, our research chat, deliberately hard-stops on pregnancy, breastfeeding, and trying-to-conceive questions rather than answer them.

What evidence grade does Follistatin-344 have, and why?

Follistatin-344 carries evidence grade D. Preclinical / animal evidence only across 12 indexed studies. No human trial data.. Grades are derived from the research record, never hand-assigned; see how grades work.

Is there a female-specific dose for Follistatin-344?

No. A female-specific dose for Follistatin-344 is not established, and this site does not provide dosing or medical advice. Any figures we show describe what published research used, not a recommendation. Decide anything about use with a qualified clinician.

How is Follistatin-344 administered in research?

In the published literature, Follistatin-344 is administered via subcutaneous. Reported dose ranges on the Dosing tab describe what studies used for laboratory research, not a protocol for people. We don't provide dosing.

What side effects have been reported for Follistatin-344?

Effects reported in the research literature include insufficient human data to characterize. Sex-specific incidence has not been separately analysed in the available records, so these are not broken out for women.

How should Follistatin-344 be stored and handled?

Follistatin-344 sold for research is supplied as a lyophilized (freeze-dried) powder. Lyophilized peptides are generally kept cold and dry, at roughly -20°C for longer-term storage and 2-8°C short-term, protected from light. Once reconstituted they are typically refrigerated and used within a short window, avoiding repeated freeze-thaw cycles. This is general laboratory handling for research use only, not a directive for human use. Always follow the handling and purity details on the product's Certificate of Analysis.

Where can I buy Follistatin-344 for research?

Follistatin-344 is not currently listed by our research-use partner, Aurevena Research, but their catalog carries related compounds. Code research15 applies 15% off. We may earn a commission when you purchase through this link, at no extra cost to you. Products are for laboratory research use only.

Browse the Aurevena catalog
Research-use supplier: Follistatin-344 isn't currently listed by our research-use vendor. Their catalog carries related compounds. Code research15 for 15% off, applied automatically at checkout. We may earn a commission when you purchase through this link, at no extra cost to you. Products are for laboratory research use only.
Browse the catalog →

Citations (PMID)

41966639

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Educational information for laboratory and research use only. Not medical advice, a recommendation, or a claim of safety or efficacy; no personal dosing. “Unstudied” means no qualifying study was found, not that a compound is safe or unsafe.