FLGR242_Dosage, benefits & legal status
Also known as Follistatin FLGR242
Sold as an upgraded follistatin. Nobody outside the sellers has said what is in the vial.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is FLGR242?
Plain language first. The technical label stays, but it never stands alone.Overview
It is marketed as follistatin that lasts longer in the body.
FLGR242 is sold as a modified follistatin construct fused to an albumin-binding peptide, intended to inhibit myostatin for longer than follistatin does on its own.
What it's used for
A vendor-introduced follistatin product sold for muscle growth. Its composition rests on seller copy alone.
How does FLGR242 work?
What it does in the body, and where.The idea behind FLGR242 is straightforward. Whether the vial contains it is the open question.
- 01Myostatin limits muscle growthFollistatin binds and neutralises it, which is why follistatin is sold for muscle at all.
- 02Follistatin clears from the blood quicklyThat short duration is the practical problem this product claims to solve.
- 03The claimed fix is an albumin-binding tailA short peptide that grips serum albumin, so the construct circulates with albumin instead of being cleared on its own schedule. This is a well-established technique in real drug development.
- 04None of that tells you what is in the vialThe mechanism is plausible and the components are real. What is missing is any independent measurement showing that this particular product is the molecule described.
A schematic of the compound's mechanism, not a diagnostic image.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Muscle growth through myostatin inhibition, as soldResearch only
- Muscle wasting conditions, which is where follistatin gene therapy has been studiedEarly research
The published record
0
Papers and trials about FLGR242
Europe PMC was searched on 12 October 2026 and returned nothing.
Counted from Europe PMC indexing, not read by a person.
At a glance
Four things to know about FLGR242
Evidence
Category
Muscle building
Common vial
10 mg
Half-life
No published figure for this construct
How much, and do you cycle it?
The range, and whether you take breaks.No established dose, no established schedule. No established schedule No range
Nothing has been studied, so nothing can be recommended. Schedules quoted for it are borrowed from follistatin.
No published figure for this constructNo figure
The albumin-binding peptide it claims to carry, SA21, was measured on its own at about 2.3 hours in rabbits. Fused to an antibody fragment it extended that fragment's half-life 37-fold in rabbits. Neither figure is a half-life for FLGR242, and no measurement of this product has been published.
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
FLGR242 starts at $99.00 across 2 vendors.
12 listings, last read Oct 10, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized FLGR242 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Ask the seller for a certificate of analysis that reports a measured mass, not just a purity percentage. A mass near 40 kDa would support the recombinant fusion protein description. A mass in the low thousands would mean you have a short synthetic peptide instead. Purity alone tells you nothing about identity.
Who should avoid it
- Any active cancer, since myostatin and activin signaling interact with tumor biology
- Existing heart disease, because myostatin is expressed in cardiac muscle
- Pregnancy and breastfeeding
- Banned in drug-tested sport
Stop and get help
- Shortness of breath, chest pain, or swelling in the legs
- Tendon pain, or a joint giving way, since muscle can outgrow the tendon that carries it
- New lumps or masses
- Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing
Common effects
- Unknown in humans
- No published human safety data for this construct
- Injection site reactions would be expected
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is FLGR242 approved?
And where the numbers on this page come from.No. FLGR242 is not approved for any use, anywhere. It is sold labeled for laboratory research only, and there is no legal route to buy it for human use.
- Approval statusResearch only
- RouteUnder the skin (subcutaneous)
- Checked24 August 2026
- DoseFrom community reports. No regulator or trial established this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
What has happened recently
Not approved anywhere, and no research program stands behind this specific construct. It is not the same thing as the follistatin FST-344 entry on this site, so the two are kept separate. The albumin-binding part is real and traceable: the sequence in the vendor description matches US patent 12,377,158 B2, Enhanced peptide constructs for albumin binding, granted 5 August 2025, whose claim 1 covers the core peptide DICLPRWGCLW attached to a GGSGGSGGSGG linker. The sole inventor is Michael Farber and the patent carries no assignee of record, so a link between the patent and any seller of FLGR242 is not established. Sellers describe the binder as patented without saying whose patent it is. Banned in drug-tested sport as a myostatin inhibitor.
Banned in drug-tested sport. Most research peptides are prohibited under WADA's S0 category, which covers any substance with no approval from any regulatory authority for human use. That means a compound can be banned without ever being named on the prohibited list. Check with your own anti-doping authority rather than assuming absence from the list means permitted.
You can compare this against the whole library, or read how to check a seller.
What else is like FLGR242?
Others in Muscle building, side by side.If you're weighing FLGR242, it's worth reading Trevogrumab, ACE-083, and Apitegromab in the same class.
Sold as an upgraded follistatin. Nobody outside the sellers has said what is in the vial.
- Dose
- No established dose
- How often
- No established schedule
A myostatin antibody trialled with semaglutide, where the three-drug version got dangerous.
- Dose
- 200 or 400 mg (trial doses)
- How often
- In the trial schedule
A muscle drug injected into one muscle at a time. It grew muscle and changed nothing functional.
- Dose
- 200 to 240 mg into one named muscle, in the trial
- How often
- Every 3 weeks in the trial
An antibody tested to stop GLP-1 weight loss taking muscle along with fat.
- Dose
- 10 mg/kg per month (trial dose)
- How often
- Monthly
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- Why Does My Peptide Injection Itch or Welt
Injection-site irritation, a histamine reaction, or a true allergy, and how to tell them apart.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
Sources
- Dennis et al., albumin binding as a general strategy for improving the pharmacokinetics of proteins, Journal of Biological Chemistry(2002)Original description of the SA21 albumin-binding peptide, Ac-RLIEDICLPRWGCLWEDD-NH2, with a 2.3 hour half-life in rabbits on its own.
- US patent 12,377,158 B2, enhanced peptide constructs for albumin binding(2025)Claims the DICLPRWGCLW core attached to a GGSGGSGGSGG linker, with an alpha-Klotho fusion in claim 4. Sole inventor Michael Farber, no assignee of record.