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

Follistatin (FST-344) at a glance

Follistatin was first identified in ovarian follicular fluid as a factor that suppresses pituitary FSH secretion, which is where its name comes from. Alternative splicing of the FST gene yields two precursors; FST-344 is the longer one, and after its signal sequence is removed it becomes the circulating form often called FST-315. It is a cysteine-rich glycoprotein of about 31.5 kDa, supplied here as white lyophilized powder, typically produced by recombinant expression.

Price and availability

This is HK Peptide‘s kit of 10 vials at 1mg each (10 mg in total), dispatched from Hong Kong, Hong Kong. $200.00 buys the whole kit, which is $20.00/mg. Of the 2 Follistatin (FST-344) listings on the marketplace, from 2 brands, this is the lowest price per mg. Funds stay in escrow and are released to HK Peptide only when you mark the order as received.

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
Also sold by: Cyprus Peptides 1mg $327.00

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.

What it is studied for

Follistatin works outside the cell as a ligand trap. Follistatin molecules wrap around a dimeric ligand such as activin A or myostatin, covering the surfaces that would otherwise contact type I and type II receptors. With the ligand sequestered, SMAD2/3 phosphorylation falls, relieving a brake on muscle growth in experimental models. It also binds certain bone morphogenetic proteins with lower affinity. Heparin-binding regions influence whether a given isoform circulates or stays tethered in tissue, which researchers consider when interpreting results.

Research and regulatory status

Mouse studies are striking: genetic overexpression produces large increases in muscle mass, and gene-delivery approaches have been tested in models of muscular dystrophy, with small early human gene-therapy studies also reported. Reproductive research examines its control of activin in the ovary and pituitary. Recombinant follistatin protein is not an approved therapy. Material listed on GLP1 Forum Escrow is a research reagent, and protein quality can vary substantially between producers.

Checking the lab data

Glycoproteins need protein-style analysis. Expect SDS-PAGE or Western blot showing a band consistent with the expected size, noting that glycosylation can broaden it, plus intact-mass or peptide-mapping data and an HPLC or size-exclusion purity figure that reveals aggregates. The report should name the expression system, give protein content by a stated assay, and ideally include a binding or activity measurement. Endotoxin results are relevant for recombinant protein.

No independent report is attached to this listing yet. You can compare brands that publish one on the marketplace or browse the lab reports directory.

Listing details

Compound: Follistatin (FST-344)
Synonyms: FST-344
Class: Autocrine glycoprotein (TGF-beta superfamily antagonist)
Format: Lyophilized (freeze-dried) powder
Molecular weight: ~31.5 kDa (glycoprotein)
Vial strength: 1mg
Vials per kit: 10
Total content: 10 mg
Price per mg: $20.00
Sold by: HK Peptide
Ships from: Hong Kong, Hong Kong
Lab report: Not yet published

Storage and preparation

Keep unopened freeze-dried vials cold, sealed and out of the light; moisture is what degrades a lyophilized cake fastest. After reconstitution, refrigerate the solution and work within the stability window your protocol sets.

Concentration arithmetic: one 1 mg vial dissolved in 2 mL gives 0.5 mg/mL, or 1 mg/mL in 1 mL. The Research Lab calculator in your dashboard handles any other volume.

Buyer questions

What is the difference between FST-344 and FST-315?

FST-344 is the full precursor encoded by one splice variant. Once its signal sequence is removed, it becomes the mature protein commonly called FST-315, which carries an acidic tail that lowers its affinity for cell-surface heparan sulfate and lets it circulate. Products labeled FST-344 therefore generally refer to the gene variant rather than a distinct mature protein.

Why is recombinant follistatin more variable than synthetic peptides?

It is produced in living cells, so folding, glycosylation and disulfide bonding depend on the expression system and purification process. Small differences can affect activity even when purity looks high. That is why binding or activity data, alongside identity and aggregate testing, give a more complete picture of a batch than purity alone.

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

10 vials of 1mg each — 10 mg in all. Where a lab report exists, the testing panel above shows what the brand's tested sample actually measured.

What if the parcel never arrives?

Open a claim from your order page. The payment is still in escrow at that point, so a claim decided in your favour is refunded to your Escrow Wallet.

Supplied for laboratory research only. Not for human or veterinary use, and not a substitute for any prescription medicine. Nothing on this page is medical advice.