Rapamycin Dosing, Cycling, and Off-Label Use

Rapamycin (sirolimus, marketed as Rapamune) is an FDA-approved prescription drug for two narrow indications: prophylaxis of organ rejection in renal transplant recipients (2-5 mg daily, with serum trough monitoring to 5-15 ng/mL) and treatment of lymphangioleiomyomatosis (LAM) (2 mg daily). Off-label longevity prescribing has emerged as a separate practice, using intermittent low-dose regimens that look pharmacologically very different from transplant dosing. The dominant off-label protocol is 5-7 mg taken once weekly, on an empty stomach, with strict avoidance of grapefruit and inhibitors of CYP3A4 around the dose. This page documents the principal off-label dosing strategies, the pharmacokinetic and pharmacodynamic rationale for each, the practical considerations (administration, drug interactions, when to skip a dose), and the published protocols followed by clinicians who prescribe rapamycin for longevity indications. None of this constitutes medical advice; off-label rapamycin use should only happen under the care of a physician familiar with the drug.

Table of Contents

1. Transplant Dosing vs Longevity Dosing — The Fundamental Distinction
2. The Dominant Off-Label Protocol: 5-7 mg Once Weekly
3. Pharmacokinetic Rationale: Why Once-Weekly Works
4. Alternative Regimens: Biweekly, Loading, Cycling
5. Administration: Empty Stomach, Time of Day, Tablet vs Solution
6. Drug Interactions and What to Avoid Around the Dose
7. Dose Titration and Tolerability-Based Adjustment
8. Cycling Strategies and When to Pause
9. Clinician Protocols (Attia, Blagosklonny, Kaeberlein, Green)
10. Combination with Metformin, Berberine, Fasting
11. Sourcing, Generic Availability, and Cost Considerations
12. Key Research Papers
13. Connections

Transplant Dosing vs Longevity Dosing — The Fundamental Distinction

Understanding off-label rapamycin requires recognizing that the transplant regimen and the longevity regimen are pharmacologically very different despite using the same molecule:

The longevity dosing strategy is built on the explicit pharmacological hypothesis that lifespan-extending effects derive from periodic mTORC1 inhibition while immunosuppression and metabolic toxicity require sustained inhibition of both mTORC1 and mTORC2. The Lamming 2012 paper in Science provided the foundational mouse data dissociating these two effects, and the Arriola Apelo 2016 paper in Aging Cell demonstrated lifespan extension with intermittent rapamycin in mice without the metabolic side effects of daily dosing.

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The Dominant Off-Label Protocol: 5-7 mg Once Weekly

The most commonly prescribed off-label longevity regimen in 2026 is:

• Dose: 5-7 mg of sirolimus, typically as 1 mg tablets
• Frequency: Once weekly (same day each week, e.g., every Sunday)
• Timing: Empty stomach, ideally morning, no food for 2 hours before and 1 hour after
• Co-administration: Avoid grapefruit and grapefruit juice on dose day and for 2 days after; avoid CYP3A4 strong inhibitors (ketoconazole, clarithromycin, ritonavir) entirely
• Monitoring labs: Lipid panel, A1c, fasting insulin, CBC, CMP at baseline and every 3-6 months
• Pause indications: 1-2 weeks before and 2 weeks after any surgery; for any active bacterial, viral, or fungal infection; for any planned vaccination (Mannick data suggests rapamycin around vaccination may actually be beneficial, but most off-label protocols pause to be conservative)

The 5-7 mg dose range is anchored by allometric scaling from mouse studies (the doses that extended mouse lifespan, scaled to human body weight, would correspond to approximately 0.5-1 mg/kg total weekly — about 35-70 mg/week for a 70 kg adult) but reduced by an order of magnitude because intermittent human dosing produces much higher peak blood concentrations per mg than continuous mouse food-spiked dosing, and because the goal is to spare mTORC2 by limiting total exposure. The 5-7 mg/week range corresponds to weekly trough concentrations well below the transplant target.

Some clinicians start lower (3 mg/week for 4-6 weeks) and titrate up based on tolerability, particularly the appearance of mouth ulcers. Others start at the target dose immediately, accepting that the first few doses may produce more side effects.

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Pharmacokinetic Rationale: Why Once-Weekly Works

The pharmacokinetic basis for once-weekly dosing rests on three properties of sirolimus:

1. Long terminal half-life (~62 hours in humans). A 6 mg dose taken Sunday morning produces meaningful blood concentrations through Wednesday, with measurable but low trough by the following Sunday. This extended exposure allows weekly dosing to achieve sustained mTORC1 modulation without the inconvenience of daily dosing.
2. High lipid solubility and intracellular retention. Sirolimus accumulates intracellularly to concentrations 10-100x higher than blood concentrations because of its lipophilicity and binding to FKBP12. This intracellular reservoir provides ongoing mTOR inhibition even after blood concentrations decline.
3. Dose-proportional pharmacokinetics in the relevant range. Doubling the dose approximately doubles the AUC (area under the curve) and the peak concentration. This linearity makes dose titration straightforward.

The pharmacodynamic correlate is that peak mTORC1 inhibition occurs within hours of the dose (peaking 1-3 hours post-dose), persists for 24-72 hours at high level, and gradually declines over the rest of the week. mTORC2 assembly disruption requires sustained exposure of approximately 1-2 weeks of continuous high blood levels — well above what weekly dosing produces. This is the molecular basis for the "intermittent dosing spares mTORC2" hypothesis.

Individual pharmacokinetic variability is substantial, however — CYP3A4 polymorphisms, P-glycoprotein (ABCB1) polymorphisms, body composition, and concomitant medications all affect sirolimus exposure. Some clinicians order a single trough level (drawn 24 hours post-dose) early in treatment to identify outlier metabolizers, then adjust dose accordingly. Routine therapeutic drug monitoring is generally not done for off-label longevity use because there is no validated target level for this indication.

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Alternative Regimens: Biweekly, Loading, Cycling

Several variations on the once-weekly protocol are in active use:

• Biweekly (every two weeks) — some protocols use 6-10 mg every two weeks instead of weekly. The rationale is even more conservative mTORC2 sparing and reduced cumulative exposure. The trade-off is that mTORC1 inhibition is much lower in the second week between doses, possibly missing the "sustained low-level mTORC1 modulation" that may be the active pharmacodynamic. Less common in current practice.
• Loading dose protocols — some Eastern European clinicians (influenced by Mikhail Blagosklonny's writings) use larger initial doses (10-15 mg) for the first 2-3 weeks before settling into weekly maintenance. Rationale is faster establishment of intracellular drug reservoir. Limited published data; higher side-effect rates expected during loading.
• Higher weekly doses (8-10 mg) — some clinicians, particularly for patients perceived as having "metabolic resistance" to intervention or for older subjects (age 70+), push doses higher. The cost is more mouth ulcers and lipid elevation; the hypothesized benefit is more robust mTORC1 inhibition. The available human data does not yet establish whether higher intermittent dosing produces better outcomes; the Miller 2014 mouse dose-response data suggests dose-response continues into higher ranges.
• Cycling on/off (3 months on, 1 month off; or 6 months on, 1 month off) — some protocols build in deliberate drug-free intervals to allow full mTORC2 recovery, restoration of normal immune surveillance, and any residual drug clearance. Rationale is theoretical; no controlled human data establishes optimal cycling. The Bitto 2016 mouse paper showing lasting benefit from transient treatment provides some support for the cycling concept.
• Twice-weekly with smaller doses — less common; some clinicians prescribe 3 mg twice weekly (e.g., Sunday and Wednesday) on the theory that this maintains more even mTORC1 inhibition. Pharmacologically the result is closer to continuous dosing and may not preserve mTORC2 sparing as well as true once-weekly.

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Administration: Empty Stomach, Time of Day, Tablet vs Solution

The practical administration details matter because sirolimus pharmacokinetics are sensitive to formulation, food, and timing:

• Empty stomach. Food (particularly fatty food) increases sirolimus absorption variability. The FDA prescribing information instructs consistent timing relative to food. Off-label longevity protocols typically take the weekly dose on an empty stomach in the morning, with no food for at least 2 hours before and 1 hour after. Water is fine.
• Time of day. Most off-label users dose in the morning. There is no strong pharmacodynamic argument for morning over evening, but morning timing allows the mouth-ulcer-prone period (24-72 hours post-dose) to coincide with normal eating windows where patients can identify and treat ulcers early.
• Tablet vs oral solution. Sirolimus is available as both 1 mg tablets and a 1 mg/mL oral solution. The oral solution is less commonly used for off-label longevity but offers more flexible dose titration (especially for sub-1 mg adjustments). Tablets have more consistent bioavailability and are easier to take.
• Generic vs brand. Generic sirolimus has been available since 2014 and is now substantially cheaper than brand Rapamune. Bioequivalence is established. Off-label longevity use almost universally uses generic.
• Splitting tablets. Sirolimus tablets are not scored and the manufacturer recommends against splitting. Practical reality: many users split for fine dose titration. The drug is reasonably stable in the tablet, so splitting is feasible but introduces some variability.
• Storage. Room temperature, original container, away from light. The oral solution requires refrigeration. Tablets are stable for the labeled shelf life.

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Drug Interactions and What to Avoid Around the Dose

Sirolimus is a substrate for both CYP3A4 (the principal metabolic enzyme) and P-glycoprotein (an intestinal efflux transporter). Drugs that inhibit either dramatically increase sirolimus exposure; drugs that induce either dramatically decrease it. Key interactions:

• Grapefruit and grapefruit juice — potent intestinal CYP3A4 inhibition lasting 24-72 hours after consumption. Can double or triple sirolimus blood levels. Avoid grapefruit on dose day and for at least 2 days before and after.
• Macrolide antibiotics (clarithromycin, erythromycin) — strong CYP3A4 inhibitors. Avoid co-administration. Azithromycin is a weaker inhibitor and generally compatible.
• Azole antifungals (ketoconazole, itraconazole, voriconazole, posaconazole) — very strong CYP3A4 inhibitors. Pause sirolimus during any treatment course.
• HIV protease inhibitors (ritonavir, indinavir, nelfinavir) — very strong CYP3A4 inhibitors. Sirolimus contraindicated.
• Diltiazem and verapamil (calcium channel blockers) — moderate CYP3A4 inhibitors. Substantially raise sirolimus levels. If used concurrently, consider dose reduction.
• Cyclosporine — raises sirolimus levels through both CYP3A4 inhibition and P-glycoprotein inhibition. Used together in transplant medicine with careful dosing; not relevant to off-label longevity use.
• Statins (atorvastatin, simvastatin, lovastatin) — the statins themselves are CYP3A4 substrates, so the interaction is bidirectional. Rapamycin elevates statin exposure, increasing rhabdomyolysis risk. Many off-label longevity users either take statins on a different day from rapamycin or switch to a non-CYP3A4 statin (rosuvastatin, pravastatin).
• Rifampin — potent CYP3A4 inducer. Dramatically lowers sirolimus levels. Avoid concurrent use.
• St. John's Wort — herbal CYP3A4 inducer. Lowers sirolimus levels meaningfully. Avoid.
• Phenytoin, phenobarbital, carbamazepine — anticonvulsant CYP3A4 inducers. Lower sirolimus levels. Co-administration discouraged.
• Live vaccines — should be administered before starting rapamycin if possible; chronic high-dose rapamycin theoretically reduces vaccine immunogenicity, though Mannick's data suggest the opposite for inactivated vaccines at low intermittent doses.

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Dose Titration and Tolerability-Based Adjustment

The dominant titration approach is symptom-based, anchored to mouth ulcers as the most reliable dose-dependent side effect:

1. Start at 3 mg weekly for 4-6 weeks. This is a gentle starting dose that most people tolerate without significant mouth ulcer or lipid effects.
2. If no mouth ulcers, increase to 5 mg weekly for another 4-6 weeks.
3. If still no mouth ulcers, increase to 6-7 mg weekly as the maintenance dose.
4. If mouth ulcers develop at any step, the typical response is to drop back to the previous dose. Some clinicians continue at the ulcer-producing dose for 2-3 additional doses to see if tolerance develops (it sometimes does).
5. Re-check labs at 8-12 weeks after each dose change to verify lipid and glucose markers remain acceptable.

This pragmatic titration is anchored to symptoms because there is no validated target serum trough for the longevity indication and there are no validated biomarkers that reliably predict who will benefit at which dose. Some clinicians additionally check baseline and on-treatment biological-age estimates (DNAm clocks, GlycanAge, others), but these are research-grade rather than validated clinical tools.

For older patients (age 70+) or those with multiple comorbidities, lower doses (3-5 mg weekly) are generally preferred because the side-effect-to-benefit ratio may be less favorable. For younger off-label users (age 50-65), higher maintenance doses (6-8 mg weekly) are more common.

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Cycling Strategies and When to Pause

Recommended pause indications (across most off-label protocols):

• Active infection — bacterial, viral, or fungal. Pause until resolution plus 1-2 weeks. Mild upper respiratory illnesses are generally fine to dose through; pneumonia, cellulitis, urinary tract infections, or anything requiring antibiotic treatment warrant a pause.
• Planned surgery — pause 1-2 weeks before any planned surgical procedure and resume 2 weeks after, to minimize the wound-healing impairment risk. For elective dental procedures (e.g., a routine extraction), 1 week off either side is usually sufficient. For major orthopedic, abdominal, or cardiac surgery, the pause should be longer (4 weeks on either side) and ideally discussed with the surgical team.
• Active mouth ulcers — pause until they resolve, then resume at a lower dose.
• Significant unexplained lipid elevation or new-onset glucose intolerance — pause, investigate, consider dose reduction or alternative interventions.
• Pregnancy planning — rapamycin is teratogenic in animal studies and contraindicated in pregnancy. Discontinue at least 12 weeks before conception attempt for both partners. Not appropriate for anyone planning to become pregnant or who could become pregnant without contraception.
• Significant unintentional weight loss — rapamycin can suppress appetite modestly; in older patients particularly, unintentional weight loss warrants pause and assessment.

Some protocols additionally build in routine cycling (e.g., 3 months on / 1 month off, or 6 months on / 1 month off). The rationale is theoretical: allow full mTORC2 recovery, restore peak immune surveillance, allow tissue regeneration. No randomized data establishes whether cycling produces better outcomes than continuous weekly dosing.

For patients planning to receive any vaccination, the timing question is unresolved. Mannick's RAD001 data suggests low-dose rapamycin around vaccination may improve immune response. Most off-label protocols nonetheless pause 1 week before and 1 week after vaccination as a conservative default.

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Clinician Protocols (Attia, Blagosklonny, Kaeberlein, Green)

Several physicians and scientists have publicly described their approaches to off-label rapamycin longevity use:

• Peter Attia (longevity-focused concierge physician, author of Outlive) has publicly described prescribing rapamycin to many of his patients at approximately 5-7 mg weekly, with comprehensive baseline and ongoing lab monitoring, integrated with broader interventions including exercise (the "Zone 2" cardiovascular base plus high-intensity intervals), strength training, dietary protein optimization, sleep, and selective other supplements. His public writing emphasizes that rapamycin is an experimental decision based on the totality of evidence, not a proven intervention.
• Mikhail Blagosklonny (oncologist and gerontologist who advocates strongly for rapamycin as a geroprotector) has published multiple opinion articles in the journal Aging describing 5-10 mg weekly regimens as the appropriate longevity dose, often with dose escalation strategies and emphasis on early starting age (40s and 50s rather than waiting until 60s and 70s).
• Matt Kaeberlein (University of Washington biogerontologist, founder of the Dog Aging Project, prominent in the rapamycin research community) has publicly discussed taking rapamycin himself at intermittent dosing and is leading multiple human and dog trials. His public writing emphasizes the strength of the animal evidence while acknowledging the absence of direct human longevity data.
• Alan Green (semi-retired physician in New York who began prescribing rapamycin off-label early in the longevity movement) has published descriptive patient cohort data, including a registry of over 1,000 patients on intermittent rapamycin. His protocol is typically 6 mg weekly with monthly intervals adjusted based on tolerability.

The convergence across these clinicians is striking: all use intermittent (weekly to biweekly) low-dose regimens in the 5-7 mg range, with comprehensive lab monitoring and integration with broader lifestyle interventions. None claim a proven longevity effect; all describe rapamycin as an evidence-informed experimental decision.

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Combination with Metformin, Berberine, Fasting

Many off-label longevity protocols combine rapamycin with other interventions that also target mTORC1, AMPK, or related nutrient-sensing pathways:

• Metformin (500-2000 mg daily) — activates AMPK, which inhibits mTORC1 indirectly. Theoretical combination synergy with rapamycin (different mechanism of mTORC1 inhibition, possible additive effect). ITP mouse data showed metformin + rapamycin produced lifespan extension similar to rapamycin alone, not strongly additive. Many off-label users take both anyway. See Metformin page.
• Berberine (500-1500 mg daily) — natural AMPK activator with similar mechanism to metformin. Sometimes substituted for metformin in off-label longevity protocols. See Berberine page.
• Intermittent fasting / time-restricted eating — produces alternating mTORC1 cycling through dietary mechanism. Pharmacologically partially redundant with intermittent rapamycin but mechanistically convergent. See Intermittent Fasting page.
• Methionine and leucine restriction — reduce amino-acid signaling to mTORC1. Practical implementation: plant-leaning protein sources, occasional fasting-mimicking diet cycles, avoidance of high-leucine BCAA supplements.
• NAD+ precursors (NMN, NR) — act on a different pathway (sirtuin activation, mitochondrial function). Theoretical combination value; limited direct evidence of synergy with rapamycin. See NAD+ page.
• Senolytics (D+Q, fisetin) — clear senescent cells (different from rapamycin's senolysis-attenuating effect on SASP). Compatible combination. See Senolytics page.

The practical consideration with combinations is monitoring complexity. Each additional intervention adds potential side effects, drug interactions, and confounders for assessing whether the rapamycin is producing measurable benefit. Many cautious clinicians introduce one intervention at a time with adequate observation windows.

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Sourcing, Generic Availability, and Cost Considerations

Sirolimus is widely available as a generic prescription medication in the United States, Canada, the European Union, the United Kingdom, Australia, and most developed markets. Practical sourcing considerations:

• Prescription required. Sirolimus is a prescription-only drug. Off-label longevity use requires a physician prescription. Telehealth services such as AgelessRx specialize in this prescribing pathway in jurisdictions where it is legal.
• Cost. Generic 1 mg tablets are typically $1-3 per tablet through US retail pharmacies, somewhat less through international mail-order pharmacies. A 6 mg/week regimen costs approximately $25-75 per month depending on source.
• Insurance coverage. Off-label longevity use is generally not covered by insurance. Patients pay out of pocket.
• Source verification. Some patients source sirolimus through unregulated international pharmacies. Quality and authenticity can be variable. US compounding pharmacies are another option for those needing specific dose forms.
• Storage and expiration. Tablets are stable for the labeled shelf life (typically 24 months from manufacture) at room temperature in the original container.

The cost of monitoring labs (lipid panel, A1c, CBC, CMP, fasting insulin quarterly to semi-annually) often exceeds the cost of the drug itself for self-pay patients. Patients with insurance coverage of routine labs typically have these covered.

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Key Research Papers

1. Mahmood I (2010). Clinical pharmacology of sirolimus: a review. Clinical Pharmacokinetics. — PubMed
2. Zimmerman JJ et al. (1999). Pharmacokinetic interaction between sirolimus and grapefruit juice in healthy volunteers. — PubMed
3. Arriola Apelo SI et al. (2016). Intermittent administration of rapamycin extends the life span of female C57BL/6J mice. Journals of Gerontology. — PubMed
4. Blagosklonny MV (2019). Rapamycin for longevity: opinion article. Aging. — PubMed
5. Kraig E et al. (2018). A randomized control trial to establish the feasibility and safety of rapamycin treatment in an older human cohort. Experimental Gerontology. — PubMed
6. Lamming DW et al. (2012). Rapamycin-induced insulin resistance is mediated by mTORC2 loss and uncoupled from longevity. Science. — PubMed
7. Bitto A et al. (2016). Transient rapamycin treatment can increase lifespan and healthspan in middle-aged mice. eLife. — PubMed
8. Mannick JB et al. (2014). mTOR inhibition improves immune function in the elderly. Science Translational Medicine. — PubMed
9. Sehgal SN (2003). Sirolimus: its discovery, biological properties, and mechanism of action. Transplantation Proceedings. — PubMed
10. Mahe E et al. (2005). Cutaneous adverse events in renal transplant recipients receiving sirolimus-based therapy. — PubMed
11. Augustine JJ et al. (2007). Use of sirolimus in solid organ transplantation. Drugs. — PubMed
12. Selvarani R et al. (2021). Effect of rapamycin on aging and age-related diseases — past and future. GeroScience. — PubMed

PubMed Topic Searches

• PubMed: Off-label rapamycin longevity dosing
• PubMed: Sirolimus PK and interactions
• PubMed: Intermittent weekly rapamycin
• PubMed: Rapamune FDA prescribing
• PubMed: Rapamycin + metformin combination

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Connections

• Rapamycin Overview
• Rapamycin Benefits Hub
• mTOR Inhibition Mechanism
• Longevity Evidence
• Side Effects & Monitoring
• Metformin
• Berberine
• Intermittent Fasting
• Caloric Restriction
• NAD+ / NMN / NR
• Senolytics
• Lipid Panel
• Fasting Insulin
• HbA1c
• Complete Blood Count

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