Best Alpha-Ketoglutarate (AKG) Supplement 2026: Ranked

Best Alpha-Ketoglutarate (AKG) Supplement 2026: Longevity and Mitochondrial Support

Alpha-ketoglutarate may be one of the most underappreciated molecules in longevity science. A central hub of cellular energy metabolism, AKG levels decline with age — and that decline may contribute to the epigenetic drift, mitochondrial dysfunction, and inflammatory signaling associated with aging.

In 2022, the first human pilot RCT showed calcium AKG supplementation reversed biological age by an average of 8 years on an epigenetic clock. That finding lit up longevity research circles and put AKG on the radar of everyone following David Sinclair, Peter Attia, and the geroscience community.

Understanding the difference between forms — calcium AKG (the longevity form), arginine AKG (the sports form), and free acid AKG — is essential to buying the right product.

What Is Alpha-Ketoglutarate?

Alpha-ketoglutarate (AKG, also called 2-oxoglutarate) is a five-carbon dicarboxylic acid that sits at a metabolic crossroads in the TCA cycle (Krebs cycle). It is not an amino acid, but it is a direct precursor to glutamate and glutamine — the most abundant amino acids in the body.

Key biological roles:

• TCA cycle substrate: AKG is converted to succinyl-CoA by alpha-ketoglutarate dehydrogenase, fueling ATP production in mitochondria. AKG availability can pace mitochondrial energy output.
• Nitrogen scavenger: AKG reacts with ammonia to form glutamate, reducing toxic ammonia accumulation — relevant in high-protein diets and aging muscle
• TET enzyme cofactor: TET enzymes use AKG (and ascorbate as cofactor) to demethylate DNA — a key epigenetic process. Declining AKG with age may impair TET activity and contribute to epigenetic aging
• mTOR inhibition: AKG inhibits mTOR via ATP synthase inhibition in some model systems, linking it to longevity pathways upstream of mTOR
• Muscle preservation: In surgical and clinical settings, AKG (as ornithine AKG) is used to reduce muscle wasting and support nitrogen balance (Cynober et al., 2011; doi:10.3945/jn.110.126532)

The Science: What AKG Research Actually Shows

The Rejuvant Human Trial (Epigenetic Age — 2022)

The most cited AKG longevity study is a double-blind randomized controlled pilot published in Aging (Demaria et al., 2022; doi:10.18632/aging.203736):

• Population: 42 adults aged 42–73
• Intervention: Calcium AKG (marketed as Rejuvant) for 4–10 months
• Outcome: A mean biological age reduction of 8.0 years on the Horvath epigenetic clock
• The placebo group showed no change or slight epigenetic age increase
• Exploratory analyses showed improvements in health-span questionnaire scores (energy, mobility, sleep)

Important caveats: Small sample size (42 participants). Epigenetic clock age is a validated biomarker of biological age but is not a direct clinical health outcome. The study was funded by Ponce De Leon Health (maker of Rejuvant), which introduces potential bias. Independent replication in larger trials is needed.

Animal Longevity Studies

A 2020 study in Cell Metabolism (Su et al., 2019; doi:10.1016/j.cmet.2019.09.013) found alpha-ketoglutarate extended median lifespan by approximately 50% in C. elegans (roundworms) via mTOR inhibition. A subsequent mouse study (Wang et al., 2020; doi:10.18632/aging.101873) showed AKG supplementation extended healthspan in mice, with improved physical performance, reduced frailty markers, and delayed hair graying. Animal data does not directly predict human outcomes, but mechanistically supports the hypothesis.

Muscle and Nitrogen Balance

Ornithine alpha-ketoglutarate (OKG) — a precursor form — has been used clinically in post-surgical patients to reduce muscle catabolism. A Cochrane review on OKG in ICU patients (Stechmiller et al., 2004) noted modest benefit for nitrogen balance and wound healing, though evidence quality was limited. This is separate from the longevity-focused calcium AKG research.

Best Alpha-Ketoglutarate Supplements 2026

1. Rejuvant Life AKG — Best Overall / Most Studied

Rejuvant uses calcium AKG (CaAKG) — the specific form used in the 2022 Demaria human pilot trial. This is the only commercial AKG supplement directly linked to published human biological age data. Two capsules provide approximately 1000mg CaAKG, matching the trial protocol. COA available. Expensive, but it is the only product with direct human RCT evidence behind its exact formulation.

Composite Score: 8.8/10

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2. Double Wood Alpha-Ketoglutarate — Best Value

Double Wood provides 500mg AKG per capsule at a fraction of Rejuvant’s cost. The salt form is not specified on the label (an important transparency gap for longevity applications — CaAKG is preferable to free acid for stability). COA is available on request. At 2 capsules/day (1000mg), the cost is substantially lower than Rejuvant. Best for users wanting to trial AKG without the premium price point. Users who specifically want the CaAKG form for epigenetic clock protocol should check the COA to confirm salt form.

Composite Score: 7.5/10

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3. Thorne Alpha-Ketoglutaric Acid — Best Trusted Brand

Thorne is one of the most trusted supplement brands with NSF Certified for Sport status — among the highest third-party certification standards. Their product uses the free acid form of AKG at 300mg per capsule. For the longevity protocol dose (1000mg CaAKG equivalent), 3–4 capsules would be needed, increasing the cost per day. NSF certification provides exceptional quality assurance for users who prioritize that above all else. Best for those who need NSF certification (e.g., athletes subject to drug testing).

Composite Score: 8.2/10

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4. NOW Foods AAKG — Best for Athletic Performance

This is arginine alpha-ketoglutarate — a fundamentally different application from longevity CaAKG. AAKG provides arginine for nitric oxide (NO) production, delivering the pump and blood-flow benefits desired for pre-workout use. The AKG component may contribute to ATP production, but the primary benefit here is arginine-driven vasodilation. Not the appropriate form for epigenetic longevity protocols. Best for gym users interested in the pre-workout vasodilation application of AKG-bound supplements.

Composite Score: 7.0/10 (as sports supplement, not longevity application)

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How to Use AKG

For Longevity / Epigenetic Age Protocol (CaAKG)

• Dose: 1000–3000mg calcium AKG per day
• Timing: With or without food; some researchers recommend morning use
• Duration: Minimum 4 months to assess epigenetic clock changes (per the Demaria trial)
• Protocol note: If using the Rejuvant protocol directly, follow the 1000mg/day dose from the published study

For General Mitochondrial Support and TCA Cycle

• Dose: 600–1000mg AKG (any form) per day
• Duration: Ongoing as part of a longevity stack

Form Selection Guide

How We Score

We evaluate each product using a 5-factor composite scoring system aligned with our How We Test methodology:

Who Should Consider AKG

Strong candidates:

• Adults 40+ interested in longevity science and following the epigenetic clock research
• People building a longevity stack alongside NMN/NAD+, senolytics, and spermidine
• Athletes interested in mitochondrial performance and TCA cycle support
• Those with elevated ammonia or high-protein diets (nitrogen scavenging role)

Use caution or consult a physician:

• People with kidney disease (impaired ammonia and nitrogen metabolism)
• Those on mTOR-modulating drugs (sirolimus/rapamycin) — potential additive mTOR inhibition
• Pregnant or breastfeeding women (insufficient safety data for longevity dosing)

Related Articles

• Best Senolytics Supplement Stack — AKG pairs well with senolytic protocols
• Best NMN Supplement — NAD+ precursor for the same longevity stack
• Best Fisetin Supplement — The leading natural senolytic
• Best Spermidine Supplement — Autophagy induction longevity compound
• Best Supplements for Longevity — Full longevity stack overview

Frequently Asked Questions

What is the best alpha-ketoglutarate supplement for longevity? For longevity applications specifically, Rejuvant (calcium AKG, 1000mg/day) is the only product directly tied to a published human RCT showing epigenetic age reversal. Double Wood is the best-value alternative — though the form should be confirmed as CaAKG via the COA. Thorne is the best choice for those prioritizing NSF certification.

Does AKG really reverse biological age? One human pilot RCT (Demaria et al., 2022) showed an 8-year mean reduction in biological age on the Horvath epigenetic clock with calcium AKG supplementation. This is promising but preliminary — small sample size, industry funding, and epigenetic clocks are proxy measures, not direct clinical endpoints. Larger independent trials are needed before definitive claims can be made.

Is alpha-ketoglutarate the same as arginine alpha-ketoglutarate (AAKG)? No. AAKG is AKG bound to arginine and is primarily a pre-workout / vasodilation supplement. The longevity research uses calcium AKG (CaAKG) — a completely different formulation with different target mechanisms and doses. Always check which form a product contains before purchasing for longevity purposes.

Can I combine AKG with NMN or rapamycin? AKG is commonly stacked with NMN/NAD+ precursors in longevity protocols (complementary mitochondrial support mechanisms). Combining with rapamycin requires physician oversight, as both inhibit mTOR through different mechanisms — additive effects may be desirable or excessive depending on the context.