Name: Follistatin 1mg (10 Vials / Kit)
Brand: HK Peptide
SKU: HK-FN1
Price: 200.00 USD
Availability: InStock

What is Follistatin (FST-344)?

Follistatin is produced by tissues throughout the body as part of normal physiology, where it helps regulate several TGF-beta superfamily signaling proteins. The isoform supplied here, FST-344, is the longer precursor form that is naturally processed into the shorter, circulating FST-315 variant.

How it is understood to work

Follistatin works by directly binding myostatin and activin, sequestering them from their activin type II receptors and preventing the downstream Smad signaling that normally restrains muscle fiber growth. In research models, this neutralization is associated with reduced myostatin-pathway signaling and increased muscle protein synthesis.

Research status

Follistatin’s biology has been studied extensively in mouse genetic and overexpression models, where it produces pronounced muscle hypertrophy, and it remains an active research tool in muscle-wasting conditions such as muscular dystrophy and cachexia. Reproductive biology research also studies its role in activin regulation within the gonads; clinical development of follistatin-based therapeutics is ongoing but not yet an approved treatment.

This listing: HK Peptide Follistatin (FST-344)

Brand: HK Peptide
Kit: 10 vials × 1 mg (10 mg in total)
Price per vial: $20.00
Price per mg: $20.00

Lab testing

There is no public lab report for this listing yet. We can ask the brand for the batch COA before you order. Many buyers also split an independent HPLC test with others who bought the same batch.

Request the batch COA · How group testing works

Bought through escrow: the brand is only paid after you confirm delivery. If the parcel never arrives, or an independent test shows the wrong compound or a significant under-fill, open a claim before releasing payment.

Specifications

Compound: Follistatin (FST-344)
Also known as: FST-344
Class: Autocrine glycoprotein (TGF-beta superfamily antagonist)
Form: Lyophilized (freeze-dried) powder
Per vial: 1mg
Molecular weight: ~31.5 kDa (glycoprotein)
Stated purity: ≥99% (HPLC)
Appearance: White lyophilized powder

Handling & storage

Supplied as a lyophilized powder; because it is a larger glycoprotein (approximately 31.5 kDa) rather than a short synthetic peptide, avoid excess freeze-thaw cycles, store unopened vials at -20C protected from light, and keep reconstituted solution refrigerated.

Concentration check: adding 2 ml of bacteriostatic water to one 1 mg vial gives 0.5 mg/ml. The Research Lab calculator in your dashboard works this out for any volume.

Questions

How is Follistatin different from a myostatin-inhibitor peptide?

Follistatin is a full glycoprotein that binds myostatin (and activin) directly, whereas some other research compounds work indirectly on myostatin signaling; its larger size and dual myostatin/activin activity distinguish it structurally and functionally.

What should a COA show for a glycoprotein like this?

Look for confirmation of the FST-344 isoform (not FST-315), a purity figure from HPLC or SDS-PAGE, and ideally bioactivity or binding-assay data, since glycoproteins are harder to fully characterize by mass alone than short peptides.

How much Follistatin (FST-344) is in this kit?

10 vials of 1 mg each, so 10 mg in total. The lab testing section above shows what the brand’s tested vial actually contained.

For laboratory research use only. Not for human or veterinary use. Nothing on this page is medical advice.