What Is Rapamycin Used For? Approved Uses, Per the Label

Rapamycin is the original laboratory name for the compound now marketed under the nonproprietary name sirolimus. In the United States it is a prescription medicine, available in several distinct approved products, each with its own prescribing information and its own set of indications. The compound inhibits the mechanistic target of rapamycin (mTOR), a signalling hub that regulates cell growth, proliferation and autophagy, and a 2019 review of mTOR inhibitors as cancer therapeutics described how that mechanism was translated into clinical agents and where it ran into resistance and tolerability limits (PMID 35582282).

This page summarises what rapamycin is approved for according to US labelling, the trial and review literature behind those indications, and how the indication set expanded over time. It does not describe dosing, scheduling or administration, and it does not evaluate whether any indication applies to a particular person. This page is for educational purposes only and is not medical advice; consult a licensed physician or another qualified prescribing clinician about any medical question, including whether a medicine is appropriate in an individual case.

The Approved Indications at a Glance

Sirolimus reaches patients through more than one approved product. The oral formulation carries the transplant and lung disease indications, while a protein-bound injectable formulation and a topical gel formulation carry narrower, disease-specific indications. The table below groups the approved uses by product family.

The published reviews cited on this page discuss the diseases and the drug class rather than reproducing label revision dates, so the specific revision year of each prescribing information document is not stated here. Current labelling for any of these products is published by the US Food and Drug Administration and in the National Library of Medicine DailyMed database, and a prescribing clinician or pharmacist can confirm the wording in force.

US label versions on DailyMed: Sirolimus tablets (Mylan, generic of Rapamune), DailyMed label version March 2026. The current label for the specific product governs.

Indication 1: Prophylaxis of Organ Rejection in Renal Transplantation

The first approved application of sirolimus was immunosuppression after kidney transplantation. The label frames the indication as prophylaxis of organ rejection in patients receiving renal transplants, and it specifies the immunosuppressive regimens in which sirolimus was studied. The rationale rests on the drug class mechanism: inhibition of mTOR signalling blunts the proliferative response of lymphocytes to interleukin-2, a mechanism described in the 2019 review of mTOR inhibitor pharmacology and clinical development (PMID 35582282).

Because mTOR inhibition suppresses immune function, the label carries boxed warnings covering immunosuppression, infection risk, lymphoma risk and specific transplant populations in which safety was not established. These warnings are part of the indication framework rather than an afterthought, and interpretation of them for an individual transplant recipient is a matter for the transplant team.

Indication 2: Lymphangioleiomyomatosis (LAM)

The second indication on the oral sirolimus label is treatment of lymphangioleiomyomatosis, a rare progressive cystic lung disease that occurs sporadically and in association with tuberous sclerosis complex. A 2020 review in Seminars in Respiratory and Critical Care Medicine summarised the biology, diagnosis and mTOR inhibitor based management of LAM and described sirolimus as the pharmacological therapy supported by randomised evidence in this disease (PMID 32279296).

LAM is mechanistically linked to loss of function in the TSC1 or TSC2 genes, which leads to constitutive mTOR activation, and that genetic link is the reason an mTOR inhibitor was tested in the disease at all. A 2026 disease primer on tuberous sclerosis complex described the same pathway and the role of mTOR inhibitors across TSC-related manifestations, including pulmonary involvement (PMID 41820375).

Indication 3: Malignant Perivascular Epithelioid Cell Tumour (PEComa)

A separate product, sirolimus formulated as albumin-bound protein particles for injectable suspension, carries an oncology indication for locally advanced unresectable or metastatic malignant PEComa in adults. PEComa, like LAM, is frequently driven by TSC1 or TSC2 alterations that activate mTOR, which is why an mTOR inhibitor was the logical candidate for a tumour type with no previously approved systemic therapy. The broader record of mTOR inhibitors in oncology, including the pattern of responses in biomarker-selected tumours and the obstacles encountered in unselected populations, was reviewed in 2019 (PMID 35582282).

Laboratory work has continued to map how rapamycin affects tumour signalling beyond the canonical mTOR axis. A 2022 study in Cell Chemical Biology reported that rapamycin targeted STAT3 and affected c-Myc in a way that suppressed tumour growth in the experimental systems tested (PMID 34706270). That is mechanistic research rather than an approved application.

Indication 4: Facial Angiofibroma Associated With Tuberous Sclerosis Complex

A topical sirolimus gel is approved for treatment of facial angiofibroma associated with tuberous sclerosis complex. Facial angiofibromas are among the most visible dermatological features of TSC, and the 2026 disease primer described them as part of the characteristic multisystem presentation alongside renal, neurological and pulmonary manifestations (PMID 41820375). The topical route was developed so that the lesion-directed effect could be achieved without systemic immunosuppression, and the approval applies to the topical product specifically rather than to oral sirolimus.

Regulatory History of the Indication Set

The sequence of approvals follows the biology. Transplant immunosuppression came first, reflecting the original immunological characterisation of the compound. The LAM indication followed once randomised evidence in that rare lung disease became available, and a 2020 review traced how mTOR inhibition moved from mechanism to standard pharmacological management in LAM (PMID 32279296). The PEComa and facial angiofibroma indications arrived later and belong to different products with different formulations, routes and labels.

Two features of this history are worth noting. First, indications were granted product by product, so an approval for the injectable or topical formulation does not extend to the oral tablets or vice versa. Second, several of the approved indications involve rare diseases in which TSC1 or TSC2 loss drives mTOR activation, a unifying thread described in the 2026 TSC primer (PMID 41820375).

A Related Medicine With Its Own Label: Everolimus

Everolimus is a chemically distinct rapamycin analogue with a separate prescribing information document and a separate set of indications. A 2019 review examined everolimus as adjunctive therapy for tuberous sclerosis complex associated partial-onset seizures and summarised the trial programme behind that application (PMID 31335226). Everolimus indications should not be read across to sirolimus products, and a 2022 commentary on everolimus in oestrogen receptor negative breast cancer prevention described that setting as an early-stage research question rather than an approved application (PMID 36453053).

Applications Studied but Not Approved

Several areas appear often in the rapamycin literature and are not approved indications for any sirolimus product. A 2019 study of sirolimus in extracranial arteriovenous malformations in children and adults reported on efficacy and tolerance in that setting (PMID 31386166); a 2021 review discussed proposed repurposing of rapamycin in SARS-CoV-2 infection (PMID 33807743); a 2023 review in Nature Aging examined mTOR inhibitors as candidates for targeting the biology of ageing (PMID 37142830); a 2012 methods chapter reported rapamycin-induced enhancement of vaccine efficacy in mice (PMID 22125073); a 2021 preclinical report described AAV8-hUGT1A1 combined with rapamycin in neonatal, suckling and juvenile rats as a model of treatment for paediatric Crigler-Najjar syndrome (PMID 33511243); and a 2024 review of functional lipid nanoparticles covered delivery platforms relevant to many small molecules and nucleic acids (PMID 38298556). None of these are approved uses, and research activity in an area does not establish that a medicine is appropriate for it.

Tolerability Across the Approved and Studied Settings: What Studies Report

Published work on rapamycin consistently pairs activity with tolerability constraints. The 2019 review of mTOR inhibitors as cancer therapeutics reported that toxicity and resistance were among the principal challenges limiting the class in oncology, alongside its documented successes (PMID 35582282). In the non-approved vascular malformation setting, the 2019 sirolimus study explicitly assessed tolerance alongside efficacy in children and adults (PMID 31386166). The 2023 Nature Aging review reported that the safety profile of mTOR inhibitors, including immune and metabolic effects, was a central consideration for any proposed long-horizon application (PMID 37142830). The approved labels themselves carry boxed warnings, contraindications and monitoring requirements that researchers and clinicians treat as inseparable from the indications.

Where Personal Questions Belong

Whether rapamycin or any other mTOR inhibitor is suitable for a specific person depends on diagnosis, organ function, concurrent medicines, infection risk and monitoring capacity. Those determinations sit with a prescribing clinician who can review the current prescribing information and the individual medical record. Readers looking for broader background on the compound can continue to the rapamycin overview.

References

• Lymphangioleiomyomatosis (Seminars in Respiratory and Critical Care Medicine, 2020)
• Tuberous sclerosis complex (Nature Reviews Disease Primers, 2026)
• Mechanistic target of rapamycin inhibitors: successes and challenges as cancer therapeutics (Cancer Drug Resistance, 2019)
• Everolimus as adjunctive therapy for tuberous sclerosis complex-associated partial-onset seizures (Expert Review of Neurotherapeutics, 2019)
• Everolimus for Estrogen Receptor-negative Breast Cancer Prevention: A Journey Begun? (Cancer Prevention Research, 2022)
• Rapamycin targets STAT3 and impacts c-Myc to suppress tumor growth (Cell Chemical Biology, 2022)
• Efficacy and Tolerance of Sirolimus (Rapamycin) for Extracranial Arteriovenous Malformations in Children and Adults (Acta Dermato-Venereologica, 2019)
• Rapamycin: Drug Repurposing in SARS-CoV-2 Infection (Pharmaceuticals, 2021)
• Targeting the biology of aging with mTOR inhibitors (Nature Aging, 2023)
• Rapamycin-induced enhancement of vaccine efficacy in mice (Methods in Molecular Biology, 2012)
• Efficacy of AAV8-hUGT1A1 with Rapamycin in neonatal, suckling, and juvenile rats to model treatment in pediatric CNs patients (Molecular Therapy Methods and Clinical Development, 2021)
• Advances in functional lipid nanoparticles: from drug delivery platforms to clinical applications (3 Biotech, 2024)