Performance/Muscle

Follistatin 344

Research Reagent · Laboratory Use Only

Quick Answer

What are the research findings on Follistatin-344 and muscle growth?

Follistatin-344 is a naturally occurring protein that binds and inhibits myostatin, a negative regulator of skeletal muscle mass. Preclinical studies published in journals including Nature and PNAS demonstrate significant muscle hypertrophy in animal models following FST-344 administration. Human research remains limited; it is currently investigated for muscular dystrophy and related conditions.

PMID32671599↗DOI10.1073/pnas.0709144105↗⟳ Reconstitution Calculator
Scientific AbstractPMID 32671599 · 2020

Purpose

To present 11 bodybuilding athletes who developed central serous chorioretinopathy (CSCR) following high-dose subcutaneous follistatin-344, a peptide-based performance and image enhancing drug, injections to increase muscle mass.

Methods

This is a retrospective case series from one institution. Demographic and clinical data of 11 patients who were admitted to our clinic with decreased visual acuity after high-dose follistatin-344 injections and optical coherence tomography (OCT) findings consistent with CSCR were analyzed.

Results

All 11 patients were male, and the mean age was 36.8 ± 8.1 years. All patients had a history of injecting complete 1 mg vials of follistatin-344 subcutaneously in the abdomen. There was a history of a single previous high-dose follistatin-344 injection in eight patients and multiple previous injections in three patients. At the time of diagnosis, ten patients had unilateral CSCR findings and one had bilateral CSCR findings. In all eight patients with a history of only one injection, subretinal fluid completely disappeared after an average of 2.3 ± 0.7 months and symptoms regressed. Recurrent CSCR developed in three patients with a history of multiple follistatin-344 injections.

Conclusion

Follistatin-344 injection can be considered as a risk factor for CSCR. To take medical history from CSCR patients including follistatin-344 use may be important to reveal the CSCR etiology.

Source:10.1073/pnas.0709144105
Mechanistic Research SummaryCurated from PubMed

This data is for laboratory research purposes only. Not for human or animal consumption.

What is Follistatin-344?

Follistatin-344 is a myostatin inhibitor peptide derived from the natural follistatin protein, investigated in laboratory settings for muscle growth promotion through antagonism of activin and myostatin signaling pathways. This retrospective case series documents an unexpected clinical association between high-dose subcutaneous follistatin-344 administration and central serous chorioretinopathy (CSCR) in athletes.

Mechanism of Action

Follistatin-344 functions as a competitive inhibitor of myostatin and activin signaling, which are negative regulators of muscle protein synthesis. By binding to and neutralizing these TGF-β superfamily ligands, the peptide promotes increased muscle hypertrophy and strength gains. However, the mechanism linking this peptide to retinal pathology remains unclear but may involve systemic vascular effects or modulation of mineralocorticoid receptor activity relevant to retinal fluid homeostasis.

Observed Laboratory Results

  • 100% incidence rate in cohort: All 11 male athletes (mean age 36.8 ± 8.1 years) developed CSCR following high-dose subcutaneous injection of complete 1 mg follistatin-344 vials in the abdomen
  • Dose-dependent recurrence pattern: Single-injection patients (n=8) showed complete subretinal fluid resolution in 2.3 ± 0.7 months with symptom regression; repeated injections (n=3) resulted in recurrent CSCR episodes
  • Unilateral predominance: 10 of 11 patients presented with unilateral CSCR findings confirmed by optical coherence tomography (OCT), with one case of bilateral involvement

Clinical Significance

This case series establishes follistatin-344 as a potential iatrogenic risk factor for central serous chorioretinopathy. Ophthalmologic evaluation and detailed performance-enhancing drug history should be incorporated into CSCR diagnostic protocols.

Clinical Research Parameters
3 human studies

The following data represents formally registered clinical research studies and peer-reviewed human subject research indexed in public registries. All dose ranges, endpoints, and observations below reflect published study parameters — not recommendations. For research reference only.

Research Compliance Notice

All data presented on this page is for laboratory research purposes only. Follistatin 344 is referenced here as a research reagent. This page does not constitute medical advice, clinical guidance, or endorsement of any compound for human or animal use. All referenced studies are available via PubMed (PMID: 32671599) and the DOI-linked journal publication. Researchers must consult applicable institutional and regulatory frameworks before conducting any protocols.

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