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Legal status · United States

Is RTB101 legal in the United States?

Written by Reviewed Sep 2026

Not approvedLongevityHuman studies cited: 3

Direct answer

No. RTB101 is not an approved medicine in the United States; its classification is "Not approved; research use only". Nothing containing it is authorized for any use in people. Vials labeled "for research use only" are not exempt: that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile.

RTB101 in the United States at a glance

ClassificationNot approved; research use only
NotePhase 3 did not meet its primary endpoint. Not approved and not available. The developing company, resTORbio, did not bring it to market.
FDA approval statusNever approved. The phase 3 programme did not meet its endpoint and development for this indication did not continue.
Human studies cited3 of 3 citations on the profile
ReviewedSep 2026

Classification and note come from the RTB101 profile, checked against U.S. Food and Drug Administration (FDA) listings at the reviewed date.

What this means

  • 01

    No product containing RTB101 is approved by FDA for any use in the United States, so nothing on the market is authorized for people.

  • 02

    "Research use only" is a vendor label, not a legal category that permits human use. It does not exempt a product from medicines law.

  • 03

    Importing, supplying or promoting it for human use can fall under medicines legislation in the United States. This page is general information, not legal advice.

What RTB101 is

The most important failed trial in geroscience. Positive in phase 2a and 2b, then nothing in a 1,024-person phase 3, while the biomarker it targeted still moved in both.

If you read one page on this site about why biomarkers are not results, it should be this one. RTB101 was the drug that carried the mTOR longevity hypothesis into definitive human testing.

Mechanism: A low-dose inhibitor of TORC1. At the higher doses originally developed for oncology, dactolisib is a dual inhibitor of phosphoinositide 3-kinase and mTOR.

Regulatory history: Never approved. The phase 3 programme did not meet its endpoint and development for this indication did not continue.

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 RTB101 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.

RTB101 in other countries

Frequently asked questions

Is RTB101 legal in the United States?

No. RTB101 is not an approved medicine in the United States; its classification is "Not approved; research use only". Nothing containing it is authorized for any use in people. Vials labeled "for research use only" are not exempt: that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile. Note: Phase 3 did not meet its primary endpoint. Not approved and not available. The developing company, resTORbio, did not bring it to market.

Can I buy RTB101 in the United States?

No approved product exists to buy. In the United States RTB101 is classified as "Not approved; research use only", 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. Note: Phase 3 did not meet its primary endpoint. Not approved and not available. The developing company, resTORbio, did not bring it to market.

Is RTB101 FDA approved?

No. FDA status: Never approved. The phase 3 programme did not meet its endpoint and development for this indication did not continue.. Current US classification: "Not approved; research use only". On the evidence, 3 human studies are cited on its profile.

Related compounds in the United States

Full research profile

Mechanism, cited studies, FDA status and the full legal summary for RTB101 live on its compound profile.

RTB101 profile

This page is general information about the regulatory status of RTB101 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.