David Sinclair Longevity Protocol: Compounded vs. Branded, What's Likely

Who Is David Sinclair and Why Does His Protocol Matter?

David Sinclair is a Professor in the Department of Genetics at Harvard Medical School and co-director of the Paul F. Glenn Center for Biology of Aging Research. His 2019 book Lifespan: Why We Age and Why We Don't Have To brought sirtuin biology and NAD+ metabolism to a mass audience. Because Sinclair has described his personal supplement and drug regimen in podcast interviews and in writing, that stack has become one of the most-searched longevity protocols on the internet.

His public disclosures carry weight precisely because he occupies a credible institutional position. They also raise real questions: which of his compounds are FDA-regulated drugs, which are supplements, and where does compounding fit in?

Sinclair's Publicly Described Stack

Across multiple interviews from 2019 to 2024, Sinclair has described taking:

• 1,000 mg NMN (nicotinamide mononucleotide) daily, typically in the morning
• 1,000 mg resveratrol daily, taken with yogurt or another fat source
• 1,000 mg metformin nightly (skipped on exercise days)
• Rapamycin weekly, dose unspecified publicly
• Spermidine and vitamin D3/K2 at various points

None of this constitutes a medical recommendation. Sinclair himself has stated consistently that he is not advising others to follow his protocol.

The Institutional Context

Harvard Medical School's research on sirtuins and NAD+ metabolism is extensive and peer-reviewed. Sinclair's lab published key work showing that NAD+ repletion restores vascular function in aged mice [1]. The translation of that rodent data to human outcomes is where the evidence gets thinner and the regulatory picture gets complicated.

NMN: The Supplement That the FDA Wants to Regulate as a Drug

NMN occupies the most legally complicated position in Sinclair's stack. It is not an FDA-approved drug, but it is also no longer unambiguously a dietary supplement.

The 2022 FDA Draft Guidance

In November 2022, the FDA issued a draft guidance document proposing that NMN be excluded from the definition of a dietary supplement because it had been investigated as a new drug (IND) before being marketed as a supplement [2]. The agency cited 21 U.S.C. § 331(ll), the statutory provision that prevents a substance from being sold as a supplement if it was first authorized for drug investigation. This draft guidance has not been finalized as of early 2025, which means NMN continues to be sold by supplement companies in a state of regulatory uncertainty.

What Compounding Pharmacies Offer

Several 503A compounding pharmacies now prepare NMN capsules for patients under a physician prescription. Because compounded preparations are not FDA-approved finished drug products, they bypass the IND exclusion argument, though the FDA's ultimate regulatory position on this remains unsettled. Compounded NMN typically runs $80 to $180 per month for 500 mg to 1,000 mg daily dosing, compared with $60 to $120 per month for commercially available supplement capsules.

Human Clinical Evidence for NMN

The rodent data showing NAD+ repletion improved mitochondrial function and lifespan metrics is well-established [1]. Human trials are catching up but remain small. A randomized, placebo-controlled trial published in Nature Aging (N=25) found that oral NMN 250 mg/day for 10 weeks increased blood NAD+ levels and skeletal muscle insulin signaling in postmenopausal women with prediabetes, without significant adverse effects [3]. A separate 12-week RCT (N=66) showed NMN 250 mg/day improved muscle function and gait speed in older men [4]. Neither trial measured mortality or long-term clinical outcomes. The jump from "raises NAD+ levels" to "extends healthy human lifespan" is not yet supported by phase III data.

Metformin: The Most Evidence-Backed Compound in the Stack

Metformin is the only compound in Sinclair's protocol with a decades-long human safety record across billions of patient-years of use. It is FDA-approved for type 2 diabetes and is available as a generic (metformin hydrochloride) and as branded Glumetza and Fortamet extended-release formulations.

Off-Label Longevity Use

Physicians at longevity-focused clinics commonly prescribe metformin 500 mg to 1,000 mg daily or nightly to non-diabetic patients with a longevity rationale. This is legal in the United States. The prescribing physician assumes clinical responsibility for the off-label indication, and the patient must be informed about the off-label status.

The mechanistic rationale rests on AMPK activation and mTOR inhibition. Observational data from the UK Clinical Practice Research Datalink (N=78,241) showed that diabetic patients on metformin outlived matched non-diabetic controls who were not on metformin, a finding published in Aging Cell in 2014 [5]. That association drove the design of the Targeting Aging with Metformin (TAME) trial.

The TAME Trial

TAME is a 6-year, multi-center RCT sponsored by the American Federation for Aging Research, targeting enrollment of approximately 3,000 adults aged 65 to 79 without diabetes [6]. Its primary endpoint is a composite of incident diabetes, cardiovascular events, cancer, dementia, and all-cause mortality. TAME is the first FDA-cleared trial to use a multi-morbidity composite as a primary endpoint for an anti-aging intervention. Results are expected no earlier than 2028.

The American Diabetes Association's 2024 Standards of Care note that metformin is associated with lower cardiovascular event rates in type 2 diabetes and carries a well-characterized safety profile [7].

Compounded Metformin

Metformin is cheap as a generic, sometimes as low as $4 per month at major pharmacy chains. Compounding pharmacies do prepare metformin in custom strengths or delivery forms (liquid, topical, slow-release capsules), but for most patients the generic tablet is clinically equivalent and far less expensive. The main compounding use case is patients who want a strength or release profile not available in standard generic tablets.

Rapamycin: The mTOR Inhibitor at the Edge of Longevity Medicine

Rapamycin (sirolimus, branded as Rapamune by Pfizer) is FDA-approved as an immunosuppressant for organ transplant recipients. Its longevity use is the most speculative and immunologically risky element of Sinclair's stack.

Why Rapamycin Is on the List

Rapamycin inhibits mTORC1, a nutrient-sensing kinase complex that, when chronically activated, is associated with accelerated cellular aging. A landmark 2009 study published in Nature showed that rapamycin extended median lifespan by 9% in male mice and 14% in female mice even when started late in life [8]. No other drug has produced comparable lifespan extension in a mammalian model.

The Dose and the Risk Tension

Transplant immunosuppression uses rapamycin at 2 mg to 5 mg daily continuously. The longevity community, including clinicians like Dr. Peter Attia, generally discusses intermittent dosing of 1 mg to 6 mg weekly as a way to get mTOR inhibition without sustained immunosuppression. There is no published phase III RCT demonstrating that intermittent rapamycin extends lifespan or healthspan in healthy humans. The Dog Aging Project is studying rapamycin in companion dogs, with preliminary data suggesting cardiac benefit, but results remain preliminary [9].

Compounded Rapamycin

Pfizer's Rapamune tablets are expensive ($800 to $1,500 per month at standard transplant doses). For the lower weekly doses used off-label in longevity contexts, compounded rapamycin capsules from 503A pharmacies typically cost $40 to $120 per month. Physicians prescribing off-label rapamycin are navigating a genuine risk-benefit calculation: the immunosuppressive effect, even at low intermittent doses, may increase infection susceptibility in some patients. Wound healing impairment and hyperlipidemia are documented adverse effects in the transplant literature [10].

The table below is an original HealthRX decision framework summarizing the regulatory, evidence, and compounding status of each major compound in Sinclair's publicly described protocol. It is intended for physician reference during patient consultations and does not constitute prescribing guidance.

| Compound | Regulatory Category | Human RCT Data | Compounding Availability | Estimated Monthly Cost (Compounded) | |---|---|---|---|---| | NMN | Supplement (contested) | Small RCTs; no outcomes data | Yes, 503A | $80 to $180 | | Metformin | FDA-approved generic | Extensive (diabetes); TAME ongoing | Yes, custom strengths | $15 to $60 | | Rapamycin | FDA-approved (transplant) | None for longevity indication | Yes, 503A | $40 to $120 | | Resveratrol | Dietary supplement | Phase II trials largely negative | No Rx required | $20 to $60 | | Spermidine | Dietary supplement | Very limited | No Rx required | $30 to $80 |

Resveratrol: The Compound Where the Data Fell Apart

Resveratrol is a polyphenol found in red wine and grape skins. It was one of the compounds Sinclair's lab identified as a sirtuin activator in early research. The rodent data looked compelling in 2006. The human data largely did not replicate.

What the Trials Showed

Sirtris Pharmaceuticals, a company Sinclair co-founded, was acquired by GlaxoSmithKline for $720 million in 2008 partly on the strength of resveratrol's sirtuin-activation profile. By 2013, GSK had discontinued its resveratrol programs after phase II trials failed to demonstrate clinical benefit in multiple myeloma and other indications.

A 2014 study in JAMA Internal Medicine (N=783 older adults in the Chianti region of Italy) found that higher urinary resveratrol metabolite levels were not associated with lower rates of cardiovascular disease, cancer, or all-cause mortality [11]. The authors concluded that the findings "call into question" the health effects of resveratrol.

Sinclair has maintained that bioavailability is the core issue: resveratrol taken with dietary fat increases absorption substantially. While that pharmacokinetic argument is mechanistically plausible, it has not yet produced positive phase II or III outcomes data in humans. Resveratrol is not a prescription drug and is not compounded in any meaningful clinical sense. It is a supplement.

Spermidine and Other Stack Components

Spermidine is a polyamine found in wheat germ, soybeans, and aged cheese. It induces autophagy through a mechanistic pathway distinct from rapamycin. A prospective cohort study (N=829, Bruneck Study) published in the American Journal of Clinical Nutrition found that higher dietary spermidine intake was associated with reduced all-cause mortality over a 20-year follow-up [12]. Observational correlation is not causation, and no large RCT has tested spermidine supplementation against a longevity composite endpoint.

Sinclair has also mentioned vitamin D3, vitamin K2, quercetin, and fisetin at various points. These are all over-the-counter supplements with varying evidence bases. None requires a prescription. Fisetin showed lifespan extension in mice in a 2018 EBioMedicine study, but human trial data remains limited to small pilot work [13].

How Physicians Evaluate Patients for This Protocol

A longevity-oriented physician reviewing a patient who wants to follow a Sinclair-style protocol would typically consider the following before prescribing metformin or rapamycin off-label:

Baseline Metabolic Assessment

Standard workup includes fasting glucose, HbA1c, comprehensive metabolic panel, lipid panel, complete blood count, and inflammatory markers (hsCRP, IL-6). Metformin is contraindicated when eGFR falls below 30 mL/min/1.73 m², per the FDA label [14]. For rapamycin, baseline lipids matter because the drug commonly elevates triglycerides and LDL.

Cardiovascular Risk Stratification

The American College of Cardiology / American Heart Association 10-year ASCVD risk calculator informs whether the cardiovascular benefit argument for metformin is most applicable to a given patient. Patients with baseline 10-year ASCVD risk above 7.5% may have the most to gain from metformin's pleiotropic cardiovascular effects [15].

Monitoring Schedule

For metformin, quarterly HbA1c and annual B12 levels are appropriate given metformin's documented association with B12 malabsorption over long-term use (a large cross-sectional study found OR 1.92 for B12 deficiency in metformin users) [16]. For off-label rapamycin, monthly lipid panels and periodic CBC monitoring for leukopenia are prudent at initiation.

Informed Consent Requirements

The prescribing physician must document that the patient understands the off-label status of metformin for longevity and rapamycin for longevity, the absence of mortality endpoint data for either indication, and the specific risks associated with each drug. This is not optional. It is the standard of care for off-label prescribing under AACE and general medical ethics frameworks.

The Compounding Pharmacy Question: Quality and Oversight

When patients source NMN or rapamycin from compounding pharmacies, quality assurance is not guaranteed by the FDA in the way it is for approved finished drug products. The FDA does inspect 503B outsourcing facilities under the Drug Quality and Security Act, and those facilities must meet current Good Manufacturing Practice standards [17]. Standard 503A pharmacies operating under state pharmacy board oversight have lighter federal oversight.

Patients should ask any compounding pharmacy for a Certificate of Analysis (CoA) from an independent third-party laboratory confirming potency and purity of the compounded preparation. Without a CoA, a patient using compounded rapamycin at a nominal 2 mg weekly dose may be getting anywhere from sub-therapeutic to supratherapeutic amounts. Published analyses of compounded preparations in other drug classes have found potency deviations exceeding 20% from labeled dose, which at immunosuppressant ranges carries real clinical consequence.

What Sinclair Has Actually Said About Evidence

In a 2023 interview on the Huberman Lab podcast, Sinclair acknowledged that he is "running an experiment of one" and that the scientific community does not yet have definitive proof that his protocol extends human life. He has stated: "I am not recommending anyone else do what I do. I'm a scientist who has decided to try things on myself based on the best available data."

That framing is relevant for clinicians and patients alike. Sinclair is not a physician, and his protocol reflects his reading of mechanistic and animal data extrapolated to himself. The absence of a phase III RCT does not mean these compounds are without effect. It means the effect size and risk-benefit ratio in diverse human populations is not yet quantified.

Regulatory Trajectory: What May Change by 2028

The FDA's draft guidance on NMN, if finalized, would force NMN off supplement shelves or require manufacturers to pursue an NDA. That would likely push more patients toward compounding pharmacies or toward NR (nicotinamide riboside), a related NAD+ precursor not currently under the same IND exclusion argument. NR is available as Tru Niagen (brand by ChromaDex), an FDA-notified supplement.

The TAME trial results, expected around 2028 to 2030, will be the most significant inflection point for metformin's longevity standing. A positive composite endpoint result would substantially shift prescribing norms and could prompt a supplemental NDA from a generic manufacturer seeking an aging indication.

Rapamycin's longevity future depends partly on the Dog Aging Project data and on the design and execution of human trials currently in early planning stages. Without phase III human data, most institutional longevity medicine programs will not include rapamycin in standardized protocols.