Legal status · United States
Is SRK-439 legal in the United States?
No. SRK-439 is not approved for any medical use in the United States; its classification is "Investigational, not approved". Lawful access is limited to registered clinical trials. "Research use only" labeling on vials sold online does not make human use lawful. Human evidence to date: Preliminary.
SRK-439 in the United States at a glance
| Classification | Investigational, not approved |
|---|---|
| FDA approval status | Investigational; Phase 1 |
| Evidence level | Preliminary (research strength: Preliminary) |
| Reviewed | Sep 2026 |
Classification and note come from the SRK-439 profile, checked against U.S. Food and Drug Administration (FDA) listings at the reviewed date.
What this means
- 01
SRK-439 is being studied in registered clinical trials but has not received FDA marketing approval in the United States.
- 02
Lawful human access is limited to trial participation or a formal early-access scheme where one exists; there is no pharmacy product to prescribe.
- 03
Vials sold online "for research use only" are not trial material, and that label does not make human use lawful.
What SRK-439 is
Scholar Rock's follow-on to apitegromab, engineered for self-injection alongside GLP-1 drugs; Phase 1 readout expected in the second half of 2026.
SRK-439 targets the same pro/latent myostatin as apitegromab but is formulated for subcutaneous use in obesity. Non-human primate data showed lean-mass increases at every dose, and mouse data suggested it blunts fat regain after stopping a GLP-1 drug.
Mechanism: Antibody inhibition of pro/latent myostatin activation.
Regulatory history: Investigational; Phase 1
How FDA treats this kind of product
Approves prescription drugs by indication and polices unapproved products, including peptides sold online. Compounding pharmacies may prepare some compounds under a prescription when the FDA places them on a permitted bulk-substances category.
The classification above is the The Longevity Archive reading of U.S. Food and Drug Administration listings for SRK-439 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.
SRK-439 in other countries
Frequently asked questions
Is SRK-439 legal in the United States?
No. SRK-439 is not approved for any medical use in the United States; its classification is "Investigational, not approved". Lawful access is limited to registered clinical trials. "Research use only" labeling on vials sold online does not make human use lawful. Human evidence to date: Preliminary.
Can I buy SRK-439 in the United States?
No approved product exists to buy. In the United States SRK-439 is classified as "Investigational, not approved", so there is no licensed pharmacy product. Vendors selling it "for research use only" are not selling it for human use, and that label does not change its legal status. This site does not list or recommend vendors.
Is SRK-439 FDA approved?
No. FDA status: Investigational; Phase 1. Current US classification: "Investigational, not approved". Evidence level: Preliminary.
Related compounds in the United States
Full research profile
Mechanism, cited studies, FDA status and the full legal summary for SRK-439 live on its compound profile.
SRK-439 profileThis page is general information about the regulatory status of SRK-439 in the United States, current as of Sep 2026. It is not legal advice, and classifications change; check U.S. Food and Drug Administration directly or consult a lawyer for a specific situation. Educational use only. This database summarizes published research. It is not medical advice and contains no dosing protocols or recommendations for personal use. The Longevity Archive has no vendor relationships and does not recommend where to buy anything.