Alpha-ketoglutarate
No placebo-controlled results on biological age were located. An uncontrolled review of 42 users of an AKG product reported epigenetic age 8 years lower, and a cross-sectional study linked the same product to 1.8 years lower. Both have ties to the product. In one bone trial, AKG with calcium lowered a bone breakdown marker. Adverse effects are barely studied.
- Status
- Dietary supplement in the US.
- Also called
- AKG, Ca-AKG, calcium alpha-ketoglutarate, alpha-ketoglutaric acid, 2-oxoglutarate, Rejuvant, ornithine alpha-ketoglutarate, OKG
- Taken for
- slowing aging, longer life, biological age, epigenetic age, bone health, muscle, recovery
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help3
- LimitedLimited evidence: product users showed lower epigenetic age on one company's saliva test, in studies with no control group and ties to the seller.
- LimitedOne trial found AKG with calcium lowered a bone breakdown marker in postmenopausal women with osteopenia, but bone density did not differ from calcium alone.
- LimitedLimited evidence: ornithine alpha-ketoglutarate, a different compound given in hospital, improved nitrogen balance and wound closure in small, mixed human and animal studies.
Reported risks2
- LimitedLimited evidence: in dialysis patients, 5 of 17 stopped calcium AKG within 2 weeks for stomach and bowel upset. Trials of related AKG salts reported them well tolerated.How often is not known
- LimitedOne small study: over 36 months on calcium AKG, blood calcium rose and parathyroid hormone fell in 14 dialysis patients. No long-term study in healthy people was located.How often is not known
What people take it for, and what was found
Shown to help3
Epigenetic age
Limited evidence: product users showed lower epigenetic age on one company's saliva test, in studies with no control group and ties to the seller.
The numbers and sources
- Effect
- In a retrospective analysis of 42 people taking Rejuvant, an AKG formulation with vitamins, for an average of 7 months, DNA methylation age fell by an average of 8 years (p = 6.5 × 10⁻¹²) [1]. In a cross-sectional study of 4,260 people who bought saliva epigenetic tests, users of a delayed-release calcium AKG plus vitamin product had an average 1.8 years lower age residual. People taking regular AKG showed a smaller difference that was not significant [2].
- Population
- 42 product users with tests before and after use [1]; 4,260 test buyers, 71% using supplements [2].
- Sources
- [1], [2]
- Caveats
- Neither study had a control group or randomization. Data in [1] came from the product's users. A corresponding author of [1] is a consultant and board member for Ponce de Leon Health, the product's seller, and the test company had a service agreement with the seller. Two authors of [1] are also authors of [2], and some participants in [2] were recruited through the seller. Both studies used the same company's saliva clock [1][2]. Healthy-user and recruitment bias were noted [2]. A placebo-controlled trial of 1 g a day for 6 months in 120 biologically older adults has finished recruiting [3].
Bone turnover
One trial found AKG with calcium lowered a bone breakdown marker in postmenopausal women with osteopenia, but bone density did not differ from calcium alone.
The numbers and sources
- Effect
- Over 24 weeks, the bone breakdown marker CTX fell by up to 37.0% on AKG with calcium, and differed from calcium alone at 12 and 24 weeks. Osteocalcin did not change. Lumbar spine bone density rose 1.6% from baseline on AKG, but the 0.9% difference between groups was not significant [4].
- Population
- 76 postmenopausal women with osteopenia, given 6 g AKG and 1.68 g calcium a day or calcium alone [4].
- Sources
- [4]
- Caveats
- One 6-month trial. CTX is a marker, and bone density did not differ between groups [4].
Recovery after burns (ornithine alpha-ketoglutarate)
Limited evidence: ornithine alpha-ketoglutarate, a different compound given in hospital, improved nitrogen balance and wound closure in small, mixed human and animal studies.
The numbers and sources
- Effect
- A systematic review of 15 studies found ornithine alpha-ketoglutarate improved nitrogen balance, reduced muscle breakdown and sped wound closure in clinical studies [5].
- Population
- Clinical, animal and mechanistic studies published 1984 to 2024, mostly from France [5].
- Sources
- [5]
- Caveats
- This is a different compound, given enterally in hospital care. The review notes heterogeneity and small cohorts, and mixes human and animal studies [5].
Claimed, not studied in people1
Longer life
Not studied in people. AKG lengthened life in worms and in one mouse study, but a multi-site mouse program found no longer lifespan.
No study in people. This rests on animal studies.
The numbers and sources
- Effect
- AKG extended the lifespan of adult C. elegans worms, an effect that required ATP synthase and TOR signaling [6]. In C57BL/6 mice, calcium AKG in the diet gave a longer life with less frailty and lower levels of inflammatory cytokines [7]. In the Interventions Testing Program, AKG given to genetically mixed UM-HET3 mice at three sites did not significantly increase lifespan in males or females [8].
- Population
- C. elegans worms [6]. C57BL/6 mice [7]. UM-HET3 mice at three US sites [8].
- Sources
- [6], [7], [8]
- Caveats
- Lifespan has not been measured in people. The mouse results disagree, and the multi-site program tested a different dose or starting age from earlier work [8]. The epigenetic age studies above do not measure lifespan.
Doses studied
The bone trial used 6 g AKG with 1.68 g calcium a day for 6 months [4]. The registered placebo-controlled trial uses 1 g of sustained-release calcium AKG a day for 6 months [3]. The epigenetic studies did not report a fixed dose in their abstracts [1][2].
Risks
Reported risks2
Adverse effects in trials
Limited evidence: in dialysis patients, 5 of 17 stopped calcium AKG within 2 weeks for stomach and bowel upset. Trials of related AKG salts reported them well tolerated.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- In 19 hemodialysis patients switched from calcium carbonate, 5 of 17 (29%) were withdrawn from calcium ketoglutarate within 1 to 2 weeks for anorexia, vomiting, diarrhea or general uneasiness. All 5 had stomach or bowel symptoms beforehand, and the other 12 reported no side effects [9]. In 28 hemodialysis patients, high blood calcium occurred in 1 on calcium ketoglutarate and 8 on calcium acetate [10]. In 35 trained men, arginine AKG at 12 g a day for 8 weeks was reported as well tolerated, with clinical blood markers measured against placebo [11].
- Population
- Adults on hemodialysis [9][10]. 35 resistance-trained men aged 30 to 50 [11].
- Sources
- [9], [10], [11]
- Caveats
- The dialysis trials were open label with no placebo, in people with kidney failure, and used AKG as a phosphate binder [9][10]. Arginine AKG is a different salt [11]. No adverse event counts were located for the calcium AKG products sold for aging.
Long-term use
One small study: over 36 months on calcium AKG, blood calcium rose and parathyroid hormone fell in 14 dialysis patients. No long-term study in healthy people was located.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- In 14 hemodialysis patients given calcium AKG, a mean 4.5 g a day for 36 months, serum phosphate fell from 2.6 to 1.9 mmol/l, serum calcium rose from 2.2 to 2.47 mmol/l, and intact parathyroid hormone fell from 29 to 8 pmol/l [12]. The abstract does not report adverse events [12].
- Population
- 14 adults on hemodialysis [12].
- Sources
- [12]
- Caveats
- One uncontrolled study in kidney failure, where the falls in phosphate and parathyroid hormone were the aim of treatment [12]. It does not show what years of use do in healthy people.
Claims tested and not found
- That AKG raises bone density. In a 6-month trial, the lumbar spine bone density difference between AKG with calcium and calcium alone was 0.9%, not significant [4].
Sources
- Demidenko O, Barardo D, Budovskii V, et al. Rejuvant®, a potential life-extending compound formulation with alpha-ketoglutarate and vitamins, conferred an average 8 year reduction in biological aging, after an average of 7 months of use, in the TruAge DNA methylation test. Aging. 2021. https://doi.org/10.18632/aging.203736
- Pabis K, Wang W, Selvarajoo K, et al. Supplements and Drugs Are Associated With Biological Age in a Cohort of Exceptionally Healthy Individuals. Aging Cell. 2026. https://doi.org/10.1111/acel.70517
- Lim ZM, Chew YE, Guan L, et al. Recruitment evaluation of a gerotherapeutic randomized controlled trial testing alpha-ketoglutarate in biologically older, middle-aged adults (ABLE). Experimental Gerontology. 2025. https://doi.org/10.1016/j.exger.2025.112867
- Filip RS, Pierzynowski SG, Lindegard B, et al. Alpha-ketoglutarate decreases serum levels of C-terminal cross-linking telopeptide of type I collagen (CTX) in postmenopausal women with osteopenia: six-month study. International Journal for Vitamin and Nutrition Research. 2007. https://doi.org/10.1024/0300-9831.77.2.89
- Niederegger T, Munzinger R, Schaschinger T, et al. Metabolic and Immunomodulatory Effects of α-Ketoglutarate in Burn Injuries: A Systematic Review. Journal of Burn Care & Research. 2026. https://doi.org/10.1093/jbcr/irag002
- Chin RM, Fu X, Pai MY, et al. The metabolite α-ketoglutarate extends lifespan by inhibiting ATP synthase and TOR. Nature. 2014. https://doi.org/10.1038/nature13264
- Asadi Shahmirzadi A, Edgar D, Liao CY, et al. Alpha-ketoglutarate, an endogenous metabolite, extends lifespan and compresses morbidity in aging mice. Cell Metabolism. 2020. https://doi.org/10.1016/j.cmet.2020.08.004
- Korstanje R, Strong R, Salmon AB, et al. Astaxanthin, meclizine, mitoglitazone, pioglitazone, alpha-ketoglutarate, mifepristone, methotrexate, and atorvastatin-telmisartan do not increase lifespan in UM-HET3 mice. GeroScience. 2026. https://doi.org/10.1007/s11357-026-02201-2
- Bro S, Rasmussen RA, Handberg J, et al. Randomized crossover study comparing the phosphate-binding efficacy of calcium ketoglutarate versus calcium carbonate in patients on chronic hemodialysis. American Journal of Kidney Diseases. 1998. https://doi.org/10.1053/ajkd.1998.v31.pm9469496
- Birck R, Zimmermann E, Wassmer S, et al. Calcium ketoglutarate versus calcium acetate for treatment of hyperphosphataemia in patients on maintenance haemodialysis: a cross-over study. Nephrology Dialysis Transplantation. 1999. https://doi.org/10.1093/ndt/14.6.1475
- Campbell B, Roberts M, Kerksick C, et al. Pharmacokinetics, safety, and effects on exercise performance of L-arginine alpha-ketoglutarate in trained adult men. Nutrition. 2006. https://doi.org/10.1016/j.nut.2006.06.003
- Zimmermann E, Wassmer S, Steudle V. Long-term treatment with calcium-alpha-ketoglutarate corrects secondary hyperparathyroidism. Mineral and Electrolyte Metabolism. 1996. https://pubmed.ncbi.nlm.nih.gov/8676818/