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Science & Research

Rapamycin Longevity Research 2026: The Most Controversial Anti-Aging Drug

By Mike Hartnett
March 1, 2026 20 Min Read
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Affiliate Disclosure: CoreStacks may earn a commission through links in this article. This never influences what research we cover or how we present the evidence. Rapamycin is a prescription medication — we report what researchers and clinicians have published and publicly stated. Nothing in this article constitutes medical advice.

Table Of Content

What Is the Case for Rapamycin and Longevity?

Rapamycin has produced the most consistent lifespan extension results of any compound tested through the National Institute on Aging’s Interventions Testing Program (ITP) — the gold standard for aging research in mice. It is the only drug that has extended lifespan in mice when started late in life, across multiple independent laboratories, and in both sexes. Despite this, human longevity data remains extremely limited. A handful of clinical trials have demonstrated immune-boosting effects in elderly populations, and several larger trials are now underway. The gap between extraordinary animal evidence and scarce human data is what makes rapamycin the most debated compound in longevity research in 2026.

Key Rapamycin Research Evidence at a Glance

This table summarizes landmark rapamycin studies that have shaped the longevity conversation, drawn from peer-reviewed journals and pre-registered clinical trials.

Study Model Key Finding Year Journal/Source
Harrison et al. (ITP) Mice (genetically heterogeneous) ~9-14% lifespan extension, even when started at 600 days (roughly age 60 in humans) 2009 Nature
Miller et al. (ITP) Mice Dose-dependent lifespan extension; higher doses produced larger effects 2014 Aging Cell
Bitto et al. Mice Transient rapamycin treatment (3 months) in middle age extended lifespan 2016 eLife
Mannick et al. Humans (elderly) Low-dose mTOR inhibition improved immune response to influenza vaccination by ~20% 2014 Science Translational Medicine
Mannick et al. (PEARL) Humans (65+) RTB101 (rapalog) reduced respiratory infections in elderly by ~30.6% 2018 Science Translational Medicine
Urfer et al. (Dog Aging Project pilot) Dogs (large breed, middle-aged) Improved cardiac function markers over 10 weeks 2017 GeroScience
Kraig et al. Humans Low-dose rapamycin (1mg/day for 8 weeks) was well-tolerated in healthy elderly 2018 Experimental Gerontology
ITP Multiple Replication Studies Mice Rapamycin remains the most consistently replicated lifespan result in the ITP 2009-2025 Multiple (Aging Cell, Nature, JAMA)

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What Is Rapamycin? The Drug That Longevity Researchers Cannot Stop Talking About

Rapamycin was not designed for longevity. It was discovered in soil samples from Easter Island (Rapa Nui, hence the name) in the 1970s, isolated from the bacterium Streptomyces hygroscopicus. Originally developed as an antifungal agent, it was later found to have potent immunosuppressive properties and was approved by the FDA in 1999 as an anti-rejection drug for kidney transplant patients under the brand name Rapamune (sirolimus).

The drug works by inhibiting a protein complex called mTOR (mechanistic target of rapamycin) — specifically the mTORC1 complex. mTOR is a master regulator of cell growth, protein synthesis, and nutrient sensing. When mTOR is highly active, cells are in “growth mode” — building protein, dividing, and consuming resources. When mTOR is suppressed, cells shift toward maintenance, repair, and autophagy (the cellular recycling process that cleans up damaged proteins and organelles).

This is where the longevity connection enters: the aging research community has known for decades that caloric restriction extends lifespan in virtually every organism tested, from yeast to primates. Caloric restriction suppresses mTOR. Rapamycin suppresses mTOR pharmacologically, without requiring actual caloric restriction. In principle, it mimics one of the most well-established longevity interventions ever discovered — but in a pill.

As Matt Kaeberlein, one of the leading rapamycin researchers in the world, has explained in multiple public discussions, rapamycin is not just another longevity supplement. It is a clinically validated drug with decades of safety data in transplant populations (at much higher doses), well-understood pharmacology, and a defined molecular target. This distinguishes it from most compounds in the longevity space.

The question that has consumed aging researchers since the late 2000s is straightforward: can a drug that extends mouse lifespan by 10-25% do anything similar in humans?

The ITP Evidence: Why Rapamycin Is the Gold Standard

The Interventions Testing Program (ITP) is a collaborative initiative funded by the National Institute on Aging (NIA) that tests compounds for lifespan extension in genetically heterogeneous mice across three independent sites — the University of Michigan, the Jackson Laboratory, and the University of Texas Health Science Center. It is widely considered the most rigorous testing program for aging interventions in existence because of its multi-site design, genetically diverse mouse populations, pre-registered protocols, and independent replication.

Since the ITP began publishing results, rapamycin has stood alone in the consistency and magnitude of its findings.

The 2009 Harrison Study

The landmark 2009 study by Harrison et al., published in Nature, demonstrated that rapamycin extended lifespan in mice even when treatment began at 600 days of age — the rough equivalent of a 60-year-old human. Female mice saw approximately 14% lifespan extension. Males saw approximately 9%. This was remarkable for two reasons: first, the effect size was substantial; second, starting treatment late in life and still seeing benefit was unprecedented for a pharmaceutical intervention.

This single study launched what has become a 15+ year investigation into rapamycin’s longevity potential.

Dose-Dependent Effects

Subsequent ITP studies by Miller et al. (2014, Aging Cell) demonstrated that higher doses of rapamycin produced larger lifespan extensions, with some dosing protocols yielding extensions of up to 23% in female mice and 16% in males. This dose-response relationship strengthened the case that the effect was real and biologically meaningful, rather than an artifact.

The ITP Track Record

The ITP has tested hundreds of compounds over its history. The overwhelming majority have shown no effect on lifespan. Rapamycin remains the single most consistently positive result. A few other compounds have shown modest effects — acarbose, 17-alpha-estradiol, canagliflozin — but none have matched rapamycin’s magnitude or replicability.

As Peter Attia has discussed on The Drive podcast, the ITP results are particularly compelling because the multi-site design eliminates many of the problems that plague single-lab studies: researcher bias, strain-specific effects, environmental confounders. When three independent labs get the same result with genetically diverse mice, the data demands attention.

Transient Treatment

A 2016 study by Bitto et al. in eLife added another dimension: mice treated with rapamycin for just three months during middle age showed lifespan extension even after the drug was stopped. This finding suggested that brief exposure during a critical window might be sufficient — an important consideration for any future human application, since long-term immunosuppression would be a significant concern.

What Experts Are Saying About Rapamycin in 2026

One of the most striking aspects of rapamycin in the longevity space is that experts disagree — not on the animal data (which is widely accepted as strong), but on whether the data justifies human use today. Here is where the major voices stand as of early 2026.

Peter Attia: Took It, Then Stopped — And the Reasoning Matters

Peter Attia is perhaps the most publicly transparent longevity physician when it comes to rapamycin. On multiple episodes of The Drive podcast and in his book Outlive, Attia discussed his personal experience with rapamycin in detail.

Attia was taking rapamycin at approximately 8mg weekly in a pulsed protocol — a dosing strategy designed to intermittently inhibit mTORC1 while allowing mTORC2 (which has different downstream effects, including potentially negative metabolic impacts) to remain relatively unaffected. He was among the most high-profile physicians to publicly disclose taking rapamycin for longevity purposes.

Then he stopped.

On The Drive, Attia explained his reasoning with characteristic precision. His concerns centered on several factors:

  1. Lack of a measurable biomarker. Attia’s framework for evaluating any intervention requires a trackable metric to determine whether it is working. With rapamycin, there is no established biomarker for “longevity effect.” You cannot run a blood test three months in and know whether mTOR inhibition is producing a meaningful anti-aging effect in a human. This violates one of Attia’s core evaluation principles.
  2. Immune function concerns. While the animal data and Mannick’s human studies suggest that low-dose, intermittent rapamycin may actually enhance certain aspects of immune function, Attia has expressed concern about the complexity of mTOR’s role in immune regulation. At therapeutic (transplant) doses, rapamycin is definitively immunosuppressive. The question of whether low, pulsed doses are immune-enhancing or immune-suppressing in a given individual is not fully resolved.
  3. Unknown long-term effects at longevity doses. The transplant literature gives decades of safety data at high doses, but the “longevity dosing” protocol (weekly, low-dose) is a relatively new concept with limited human safety data over multi-year periods.
  4. The risk-benefit calculus for a healthy person. Attia has emphasized that the risk-benefit analysis for a 50-year-old in excellent health is fundamentally different from a 70-year-old with declining immune function. For a young, healthy person with decades of remaining lifespan, even a small downside risk — compounded over years — could outweigh the speculative upside.

Attia’s position is not that rapamycin does not work. It is that the evidence does not yet justify the risk for a healthy person — and that without a biomarker, you are flying blind.

For more on Attia’s complete protocol and philosophy, see our Peter Attia Longevity Protocol 2026 guide.

Matt Kaeberlein: The Researcher Pushing Rapamycin Forward

Matt Kaeberlein, formerly of the University of Washington and now leading multiple aging research initiatives, is arguably the most prominent scientific advocate for rapamycin research in aging. His work includes the Dog Aging Project — a landmark longitudinal study of aging in companion dogs that includes a rapamycin arm.

Kaeberlein has been outspoken in public lectures, on podcasts, and in published papers about several key points:

  • The animal data is unambiguous. Kaeberlein has stated publicly that rapamycin has the strongest evidence of any intervention for extending lifespan in mammals, and that the ITP results should be taken seriously by the medical community.
  • The Dog Aging Project is a critical bridge. Dogs age in a compressed timeframe compared to humans but share the same environment, many of the same diseases (cancer, cardiac disease, cognitive decline), and receive veterinary medical care. The Dog Aging Project’s rapamycin arm is designed to determine whether rapamycin can extend healthy lifespan in a large, genetically diverse mammal living in the real world. Early pilot data published in GeroScience (Urfer et al., 2017) showed improved cardiac function markers in treated dogs.
  • Low-dose rapamycin is not immunosuppressive. Kaeberlein has repeatedly emphasized the distinction between the high-dose, daily rapamycin used in transplant medicine (which is immunosuppressive) and the low-dose, intermittent protocols being studied for longevity (which appear to be immune-enhancing in multiple studies). He has described this as one of the most commonly misunderstood aspects of rapamycin in public discourse.
  • The FDA approval pathway is a barrier. Kaeberlein has been vocal about the challenge of getting rapamycin approved for a longevity indication. The FDA does not recognize “aging” as a disease, which means any clinical trial must target a specific age-related condition rather than aging itself. Kaeberlein has argued that this regulatory framework slows the translation of strong preclinical data into clinical practice.

Kaeberlein’s position is clear: the evidence base is strong enough to justify human trials, the safety profile at low doses appears favorable, and the bigger risk may be not pursuing rapamycin research aggressively enough.

David Sinclair: A Different Pathway

David Sinclair, the Harvard geneticist and author of Lifespan, has taken a notably different approach to longevity pharmacology than the rapamycin-focused researchers. Sinclair’s work centers on NAD+ biology and sirtuin activation — a fundamentally different molecular pathway from mTOR inhibition.

On the rapamycin question, Sinclair has generally acknowledged the strength of the animal data but has focused his own research and public advocacy on NMN (nicotinamide mononucleotide) as his primary longevity compound. He has discussed rapamycin in multiple interviews and podcast appearances, typically framing his position as follows:

  • The ITP data for rapamycin is compelling, but mTOR inhibition and NAD+ boosting may work through complementary mechanisms.
  • Sinclair has expressed more enthusiasm for approaches that activate sirtuins and boost cellular NAD+ levels, viewing the NAD+ decline with age as a primary driver of aging.
  • He has noted that rapamycin’s immunosuppressive history makes the path to widespread human adoption more complicated than for a supplement like NMN, which is available over the counter and generally well-tolerated.

Sinclair’s position is not anti-rapamycin. It is that the NAD+ pathway represents a more accessible and potentially complementary angle on the aging problem. Some researchers have speculated that combining mTOR inhibition with NAD+ boosting could produce synergistic effects, though direct evidence for this is limited.

For a deeper comparison of these approaches, see our Longevity Experts: Where They Agree and Disagree article.

Bryan Johnson: Rapamycin in the Blueprint Protocol

Bryan Johnson, the tech entrepreneur behind the Blueprint protocol — a comprehensive, data-driven longevity regimen tracked by extensive biomarker testing — has publicly disclosed taking rapamycin as part of his protocol.

Johnson has discussed rapamycin on the Blueprint podcast and in published protocol documentation. His approach has included:

  • Periodic rapamycin use, consistent with the low-dose, pulsed protocols discussed in the research literature.
  • Integration with his extensive biomarker tracking. Johnson measures dozens of biomarkers regularly, which gives him data on how rapamycin affects his specific physiology.
  • Willingness to add and remove compounds based on biomarker response. Johnson has adjusted his rapamycin use over time based on his data.

Johnson’s protocol is notable because he takes more interventions simultaneously than almost any public longevity figure, which makes it difficult to isolate the specific contribution of rapamycin to his results. However, his willingness to publicly share detailed biomarker data before and after rapamycin use has contributed to the broader conversation about real-world effects in healthy humans.

For Bryan Johnson’s complete protocol breakdown, see our Bryan Johnson Blueprint Protocol 2026 guide.

Brad Stanfield: Running a Rapamycin Clinical Trial

Dr. Brad Stanfield, a New Zealand-based physician and evidence-based longevity researcher with a significant YouTube following, has taken an unusually direct approach to the rapamycin question: he is running a clinical trial.

Stanfield’s PEARL (Participatory Evaluation of Aging with Rapamycin for Longevity) trial is a randomized, placebo-controlled study examining the effects of low-dose rapamycin in healthy adults over 50. The trial measures a battery of aging biomarkers including:

  • Epigenetic age (DNA methylation clocks)
  • Immune function markers
  • Metabolic parameters
  • Body composition
  • Cognitive function

Stanfield has discussed the trial extensively on his YouTube channel and in interviews. He has been transparent about his motivations: the animal data is strong, the human data is sparse, and the only way to close the gap is to run well-designed trials. He has expressed frustration that rapamycin — a generic, off-patent drug with compelling preclinical evidence — has attracted relatively little clinical trial funding compared to newer, patentable compounds.

The PEARL trial represents one of the most important ongoing efforts to bridge the animal-to-human evidence gap for rapamycin and longevity.

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Human Clinical Evidence: What We Actually Know

The human clinical data for rapamycin in aging is limited but growing. Here is what has been published as of early 2026.

Mannick et al. — The Immune Function Studies

The most cited human evidence comes from Joan Mannick’s research, originally conducted at Novartis and later through the biotech company resTORbio.

In 2014, Mannick et al. published a landmark study in Science Translational Medicine showing that low-dose everolimus (a rapamycin analog, or “rapalog”) improved the immune response to influenza vaccination in elderly subjects by approximately 20%. This was significant because immune decline (immunosenescence) is one of the hallmarks of aging, and the finding suggested that mTOR inhibition could partially reverse age-related immune dysfunction.

A follow-up study (Mannick et al., 2018) tested RTB101, a proprietary mTOR inhibitor, in a larger cohort of adults aged 65 and older. The results showed a 30.6% reduction in respiratory tract infections in the treated group compared to placebo.

These results are important for the longevity field for several reasons:

  1. They demonstrated that mTOR inhibition could be immune-enhancing in elderly humans at low doses — the opposite of the immunosuppression seen at high, transplant-level doses.
  2. They showed that the effect was clinically meaningful (fewer infections, better vaccine response).
  3. They provided safety data showing that low-dose mTOR inhibition was well-tolerated over the study periods.

However, the story has a caveat. ResTORbio, the company that licensed RTB101, ran a larger Phase 3 trial that failed to meet its primary endpoint in 2019. The company was subsequently acquired by Adicet Bio. This failure was a setback for the field, though many researchers have argued that the trial design (targeting a specific respiratory infection outcome rather than broader aging markers) was suboptimal.

Small-Scale Safety Studies

A small study by Kraig et al. (2018, Experimental Gerontology) tested low-dose rapamycin (1mg/day for 8 weeks) in healthy elderly volunteers and found it was well-tolerated with no significant adverse events. While this study was not powered to detect efficacy, it provided preliminary safety reassurance for the longevity dosing concept.

What We Don’t Have

It is important to be explicit about the gaps in the human evidence:

  • No human longevity trial. No study has measured whether rapamycin extends human lifespan or healthspan over years or decades.
  • No validated biomarker. There is no established biomarker to confirm that rapamycin is producing a longevity effect in an individual human.
  • No long-term safety data at longevity doses. The transplant literature gives long-term data at high doses, but the specific low-dose, pulsed protocols used in the longevity community have not been studied for years or decades.
  • Limited population diversity. The existing human studies have been conducted in relatively small, predominantly Western populations.

The Dosing Question: Why It Is More Complicated Than You Think

One of the most important distinctions in the rapamycin conversation is between two fundamentally different dosing approaches.

Transplant Dosing (Immunosuppressive)

In organ transplant patients, rapamycin (sirolimus) is taken daily at doses typically ranging from 2-5mg/day, titrated to achieve blood trough levels of 5-15 ng/mL. At these sustained levels, rapamycin is definitively immunosuppressive — that is the entire point. It suppresses the immune response to prevent organ rejection.

Side effects at transplant doses are well-documented and include:

  • Mouth sores (oral ulcers)
  • Elevated cholesterol and triglycerides
  • Impaired wound healing
  • Increased infection susceptibility
  • Anemia, thrombocytopenia
  • Peripheral edema

Longevity Dosing (Intermittent, Low-Dose)

The dosing protocols discussed in the longevity community are fundamentally different. Based on the ITP mouse data and the human studies by Mannick and others, the emerging longevity dosing paradigm involves:

  • Intermittent dosing: Typically once weekly, rather than daily.
  • Lower total doses: Commonly discussed protocols range from 3-8mg once per week.
  • Pulsed mTOR inhibition: The goal is to transiently suppress mTORC1 (associated with longevity benefits) while allowing recovery between doses, minimizing chronic suppression of mTORC2 (which is linked to metabolic side effects like insulin resistance).

The rationale for intermittent dosing comes from both the animal literature and the pharmacology of mTOR. mTORC1 is more sensitive to rapamycin inhibition than mTORC2 — short, pulsed exposure preferentially inhibits mTORC1 while allowing mTORC2 function to recover between doses.

Multiple researchers, including Kaeberlein and Attia, have discussed this dosing distinction publicly. The key point: the side effect profile of transplant-dose, daily rapamycin cannot be directly extrapolated to the longevity-dose, weekly protocol. They are pharmacologically different interventions targeting the same drug but at different exposures.

That said, the longevity dosing protocol has not been validated in long-term human trials. The theoretical rationale is sound, but the clinical evidence is preliminary.

Safety Profile: What the Published Research Shows

Because rapamycin has been used in transplant medicine for over 25 years, its safety profile is better characterized than most compounds discussed in the longevity space. However, the safety data comes almost entirely from high-dose, chronic use in immunocompromised patients — a very different context from low-dose, intermittent use in healthy individuals.

Side Effects at Transplant Doses

The transplant literature documents the following side effects:

  • Oral ulcers (aphthous stomatitis): One of the most commonly reported side effects, occurring in a significant percentage of patients at therapeutic doses.
  • Hyperlipidemia: Rapamycin commonly raises LDL cholesterol and triglycerides. This is a well-documented metabolic effect.
  • Impaired wound healing: mTOR inhibition slows cellular proliferation, which can delay wound repair.
  • Hematologic effects: Anemia and low platelet counts have been reported.
  • Metabolic effects: Insulin resistance and glucose intolerance have been observed at high doses, likely mediated through mTORC2 inhibition.
  • Infections: At immunosuppressive doses, increased infection risk is expected and documented.

Preliminary Safety at Longevity Doses

The limited data from low-dose studies (Kraig et al., 2018; Mannick et al., 2014, 2018) suggest a substantially milder side effect profile at longevity-relevant doses:

  • Oral ulcers were reported at lower frequency and severity.
  • The immune function studies actually showed improved immune response, not suppression.
  • Metabolic effects appeared less pronounced with intermittent dosing.
  • The Kraig study specifically noted good tolerability over 8 weeks at 1mg/day.

Critical Unknowns

Several safety questions remain unanswered:

  • Multi-year safety at longevity doses: No study has followed healthy individuals taking low-dose, weekly rapamycin for more than a few months.
  • Interactions with other longevity interventions: Many people in the longevity community combine rapamycin with other compounds (metformin, NMN, various supplements). Interaction data is sparse.
  • Cancer risk: mTOR inhibition has anti-cancer properties at therapeutic doses (several rapalogs are approved cancer drugs). However, the effect of intermittent, low-dose mTOR inhibition on long-term cancer risk in healthy individuals is unknown.
  • Population-specific risks: Safety in younger individuals, women specifically, and diverse ethnic populations at longevity doses is not well-established.

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Current Clinical Trials: What Is Underway in 2026

The clinical trial landscape for rapamycin and aging has expanded substantially in recent years. As of early 2026, key registered trials on ClinicalTrials.gov include:

The PEARL Trial (Brad Stanfield)

The Participatory Evaluation of Aging with Rapamycin for Longevity trial is one of the most closely watched studies in the longevity community. It examines low-dose rapamycin in healthy adults over 50, measuring a comprehensive panel of aging biomarkers including epigenetic clocks, immune function, metabolic parameters, and cognitive function. Stanfield has discussed interim observations on his YouTube channel, though formal results are pending peer-reviewed publication.

The Dog Aging Project (TRIAD Study)

While not a human trial, the Dog Aging Project’s Test of Rapamycin in Aging Dogs (TRIAD) study is considered a critical stepping stone. Led by Kaeberlein and a large consortium of veterinary and aging researchers, this study is evaluating rapamycin’s effects on healthspan and lifespan in thousands of companion dogs. Because dogs age in 7-10 years rather than 70-80, results from this study will arrive decades before a comparable human longevity trial could conclude.

AgelessRx Rapamycin Trials

AgelessRx, a telehealth company focused on longevity interventions, has conducted and registered multiple rapamycin-related studies, including trials examining the effects of rapamycin on visceral fat, body composition, and aging biomarkers in healthy adults.

Academic Center Studies

Several university-based research groups have registered smaller trials examining rapamycin’s effects on specific age-related outcomes including:

  • Immune function in elderly populations
  • Cardiac aging markers
  • Periodontal health (oral aging)
  • Ovarian aging and fertility preservation

The breadth of these trials reflects the growing scientific consensus that rapamycin’s animal data warrants rigorous human investigation, even if the results will take years to mature.

Rapamycin vs. Other Longevity Interventions

Understanding where rapamycin fits in the broader longevity landscape requires comparing it to other frequently discussed interventions.

Intervention Evidence Level (Animal) Evidence Level (Human) Mechanism Prescription Required?
Rapamycin Very strong (ITP, multi-site) Limited but promising mTOR inhibition Yes
Metformin Moderate TAME trial underway AMPK activation, multiple Yes
NMN/NR Mixed (strain-dependent) Limited NAD+ boosting No (supplement)
Acarbose Moderate (ITP positive) Used for diabetes Glucose metabolism Yes
Caloric Restriction Very strong Observational only Multiple pathways No
Exercise Very strong Very strong Multiple pathways No

Rapamycin occupies a unique position: it has the strongest pharmaceutical animal longevity data but is a prescription drug with meaningful safety considerations. This contrasts with exercise (strong evidence in both animals and humans, no prescription needed) and NMN (weaker animal evidence but available over the counter).

For a comprehensive comparison of how major longevity experts stack their interventions, see our Longevity Expert Stacks Compared 2026 guide.

Important Research Disclaimer

Rapamycin (sirolimus) is a prescription medication. It is approved by the FDA for the prevention of organ transplant rejection and for certain cancers (as everolimus and temsirolimus). It is NOT approved for longevity, anti-aging, or healthspan extension.

Any use of rapamycin for longevity purposes is considered off-label and should only be undertaken under the supervision of a qualified physician who can:

  • Evaluate individual risk factors
  • Order and interpret appropriate lab work (CBC, lipid panel, metabolic panel, immune markers)
  • Monitor for adverse effects
  • Adjust dosing based on individual response

CoreStacks does NOT recommend obtaining rapamycin without a prescription, using rapamycin without physician supervision, or self-dosing based on internet protocols. We report on the research. We do not provide medical advice.

If you are interested in rapamycin for longevity, discuss it with a physician who is knowledgeable about mTOR biology and aging research. Several telehealth platforms now offer consultations with physicians who specialize in longevity medicine, though insurance coverage for off-label rapamycin use is typically not available.

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Frequently Asked Questions

Does rapamycin extend human lifespan?

There is no direct evidence that rapamycin extends human lifespan. The lifespan extension data comes from mouse studies (the ITP), which have consistently shown 9-25% increases depending on dose, sex, and timing. Human studies have demonstrated immune function improvements in elderly populations, but no human longevity trial has been completed. Several are underway, including the PEARL trial, which may provide early biomarker data in the coming years.

Is rapamycin the same as sirolimus?

Yes. Rapamycin is the original name for the compound. Sirolimus is the generic pharmaceutical name. Rapamune is the brand name sold by Pfizer. Everolimus (brand name Afinitor) and temsirolimus (Torisel) are chemically modified versions called “rapalogs” that share the same mTOR-inhibiting mechanism but have different pharmacokinetic properties.

What is the difference between longevity dosing and transplant dosing?

Transplant dosing involves daily administration at 2-5mg/day to achieve sustained immunosuppression. Longevity dosing, as discussed in the research community, typically involves 3-8mg taken once weekly — an intermittent protocol designed to transiently inhibit mTORC1 while allowing recovery between doses. The two protocols produce fundamentally different pharmacological exposures and are expected to have different side effect profiles, though long-term safety data for the longevity protocol is still limited.

Why did Peter Attia stop taking rapamycin?

Attia has discussed this on The Drive podcast. His primary concerns were: the lack of a measurable biomarker to confirm the drug was producing a longevity effect, uncertainty about long-term immune effects at low doses, and the risk-benefit calculus for a healthy person in their 50s. He has not said rapamycin does not work — he has said the evidence does not yet justify the risk for his specific situation. For his full reasoning, see our Peter Attia Longevity Protocol 2026 article.

What is the Dog Aging Project?

The Dog Aging Project is a large-scale longitudinal study of aging in companion dogs, led by researchers including Matt Kaeberlein and Daniel Promislow. It includes a rapamycin arm (the TRIAD study) that is testing whether low-dose rapamycin can extend healthy lifespan in dogs. Dogs are considered a valuable model because they age in a compressed timeframe (7-10 years for large breeds), share our environment, and develop many of the same age-related diseases as humans. Early pilot data showed improved cardiac function markers in treated dogs.

Can you buy rapamycin over the counter?

No. Rapamycin is a prescription-only medication in the United States and most other countries. It cannot be legally purchased without a prescription. Some compounding pharmacies prepare rapamycin for off-label longevity use when prescribed by a physician, and some telehealth longevity clinics offer prescriptions after consultation. CoreStacks does not recommend obtaining rapamycin without a valid prescription and physician supervision.

What are the main side effects of rapamycin?

At transplant doses (daily, 2-5mg), documented side effects include oral ulcers, elevated cholesterol and triglycerides, impaired wound healing, anemia, and increased infection risk. At the lower, intermittent doses discussed for longevity (weekly, 3-8mg), the limited available data suggests a milder side effect profile. Oral ulcers remain the most commonly reported issue even at low doses. However, long-term safety data for the longevity dosing protocol is not yet available.

What are rapalogs, and are they different from rapamycin?

Rapalogs (rapamycin analogs) are chemically modified versions of rapamycin designed for improved pharmacokinetics or specific clinical applications. The main rapalogs are everolimus (Afinitor, used in cancer and transplant medicine) and temsirolimus (Torisel, used in renal cell carcinoma). They share the same fundamental mechanism of mTOR inhibition. Joan Mannick’s influential human aging studies used everolimus and RTB101 (a proprietary mTOR inhibitor) rather than rapamycin itself. Some researchers debate whether different rapalogs may have subtly different effects on longevity-relevant pathways, but this remains an active area of investigation.

Keep Reading

Sources

  1. Harrison, D.E., et al. “Rapamycin fed late in life extends lifespan in genetically heterogeneous mice.” Nature 460, 392-395 (2009). PubMed: 19587680
  2. Miller, R.A., et al. “Rapamycin-mediated lifespan increase in mice is dose and sex dependent and metabolically distinct from dietary restriction.” Aging Cell 13(3), 468-477 (2014). PubMed: 24341993
  3. Bitto, A., et al. “Transient rapamycin treatment can increase lifespan and healthspan in middle-aged mice.” eLife 5, e16351 (2016). PubMed: 27549339
  4. Mannick, J.B., et al. “mTOR inhibition improves immune function in the elderly.” Science Translational Medicine 6(268), 268ra179 (2014). PubMed: 25540326
  5. Mannick, J.B., et al. “TORC1 inhibition enhances immune function and reduces infections in the elderly.” Science Translational Medicine 10(449), eaaq1564 (2018). PubMed: 29997249
  6. Urfer, S.R., et al. “A randomized controlled trial to establish effects of short-term rapamycin treatment in 24 middle-aged companion dogs.” GeroScience 39(2), 117-127 (2017). PubMed: 28194643
  7. Kraig, E., et al. “A randomized control trial to establish the feasibility and safety of rapamycin treatment in an older human cohort.” Experimental Gerontology 105, 53-58 (2018). PubMed: 29408453
  8. Attia, P. Outlive: The Science and Art of Longevity. Harmony Books (2023). Chapters 5, 11.
  9. Sinclair, D.A. Lifespan: Why We Age and Why We Don’t Have To. Atria Books (2019).
  10. Kaeberlein, M. “The Dog Aging Project: Translational geroscience in companion animals.” Mammalian Genome 27, 279-288 (2016). PubMed: 27143113
  11. National Institute on Aging Interventions Testing Program. https://www.nia.nih.gov/research/dab/interventions-testing-program-itp
  12. ClinicalTrials.gov search: “rapamycin aging” — multiple registered trials as of February 2026.
  13. Stanfield, B. PEARL Trial updates. YouTube channel and published protocol documentation.

This article is for informational purposes only and does not constitute medical advice. Rapamycin is a prescription medication with significant potential side effects. Do not take rapamycin without consulting a qualified physician. Always consult your healthcare provider before making any changes to your health regimen. See our full medical disclaimer.

CoreStacks is an independent publication. We report on what researchers and clinicians say publicly. We do not have affiliations with pharmaceutical companies, compounding pharmacies, or rapamycin prescribers.

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Mike Hartnett

Mike tracks what leading longevity researchers actually take, test, and recommend. CoreStacks reports on expert protocols and published research to help you make informed decisions about your health.

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