--- slug: calcium-alpha-ketoglutarate type: pattern summary: "A low-cost supplement with a real mouse-lifespan signal and a weak uncontrolled human methylation claim, while placebo-controlled human trials remain unreported." created: 2026-05-22 updated: 2026-06-07 evidence_tier: "Mechanistic / animal model" cost: "$-$$" availability: Common regulatory_status: "Dietary supplement in the US; no FDA-approved aging or longevity indication" related: evidence-tiers: relation: tested-by note: "Evidence Tiers separates Ca-AKG's mouse lifespan signal, uncontrolled human methylation-clock case series, and ongoing placebo-controlled trials." aging-hallmarks: relation: uses note: "Ca-AKG claims are usually interpreted through mitochondrial metabolism, nutrient sensing, epigenetic regulation, inflammation, and frailty biology." biological-age: relation: measured-by note: "The main human claim rests on biological-age estimates rather than clinical events." epigenetic-age-testing: relation: measured-by note: "Epigenetic Age Testing explains why methylation-clock movement is a model output, not proof of longer healthy life." caloric-restriction: relation: related note: "Ca-AKG is often framed as a metabolite-level echo of caloric-restriction biology, but that mechanism does not make it a caloric-restriction substitute." senolytic-cocktails: relation: contrasts-with note: "Both categories have strong animal stories and early human signals, but neither has a healthy-adult lifespan or healthspan outcome trial." stack-creep: relation: bounded-by note: "Ca-AKG is cheap and plausible enough to become another permanent supplement without a clear endpoint." single-biomarker-tunnel: relation: bounded-by note: "The Rejuvant claim can tempt readers to chase one methylation-clock result while ignoring stronger clinical anchors." aspirational-stack-theater: relation: bounded-by note: "A supplement with a mouse-lifespan paper and a commercial clock result can become a status signal inside a large stack." mechanism-pumping: relation: bounded-by note: "TCA-cycle, mTOR, AMPK, and epigenetic mechanisms are plausible; they are not clinical outcome proof." --- # Calcium Alpha-Ketoglutarate (Ca-AKG / Rejuvant) > **Pattern** > > A named solution to a recurring problem. *Calcium alpha-ketoglutarate is a low-cost longevity supplement with a real mouse-lifespan signal, a weak uncontrolled human methylation-clock claim, and placebo-controlled human trials still waiting to report efficacy.* *Also known as: Ca-AKG, calcium AKG, AKG-Ca, Rejuvant, LifeAKG, alpha-ketoglutarate* Calcium alpha-ketoglutarate sounds more clinical than most supplement-aisle longevity products because the underlying molecule is real cellular infrastructure. Alpha-ketoglutarate is a tricarboxylic acid cycle metabolite, a nitrogen-handling node, and a cofactor for several epigenetic and collagen-related enzymes. The supplement form, Ca-AKG, wraps that metabolite in a calcium salt that can be sold as a dietary supplement. That combination creates the trap. The biology is not fake. The human longevity claim isn't proven. ## Context Ca-AKG entered the longevity stack through three routes. The first was model-organism biology: alpha-ketoglutarate extended lifespan in worms and flies, and calcium alpha-ketoglutarate later improved frailty and survival measures in mice. The second was a commercial human signal: Rejuvant, a sustained-release Ca-AKG formulation paired with sex-specific vitamins, was associated with a large reduction in a proprietary DNA-methylation age estimate in 42 self-selected customers. The third is the geroscience trial layer, especially ABLE, a placebo-controlled Singapore study testing whether 1 g/day sustained-release Ca-AKG changes DNA-methylation age in middle-aged adults selected for older methylation age than chronological age. Those routes are not equivalent. A mouse frailty study can make Ca-AKG worth studying. A customer methylation-clock case series can generate a hypothesis. A registered trial protocol can show that the field knows what evidence is missing. None of those, by itself, shows that a healthy adult who buys Ca-AKG will live longer, preserve function, or avoid disease. The regulatory frame is also modest. In the United States, Ca-AKG is sold as a dietary supplement. It is not FDA-approved to treat aging, slow biological aging, prevent disease, or extend healthspan. Commercial access should not be confused with clinical validation. ## Problem Ca-AKG is easy to over-read because every piece of the story has just enough evidence to sound stronger than it is. The molecule sits inside core metabolism. The mouse study reported a meaningful late-life frailty and survival signal. The Rejuvant paper reported an average eight-year reduction in a DNA-methylation age estimate. Ongoing trials give the category a real scientific pipeline. The problem is endpoint substitution. A methylation-clock estimate is not a clinical outcome. A frailty score in mice is not human healthspan. A branded formulation with vitamins is not the same thing as any Ca-AKG powder bought online. A supplement can look inexpensive and still consume the reader's attention, testing budget, and stack space without changing the outcome that matters. The useful question is narrower: does Ca-AKG move a validated human endpoint enough to matter, in a defined candidate group, with acceptable safety, cost, and opportunity cost? ## Forces - The metabolite is biologically plausible, but plausible metabolic wiring is not outcome evidence. - The strongest lifespan and frailty data are in mice, not humans. - The best-known human paper used 42 self-selected customers, no placebo group, no randomization, and a proprietary methylation test. - The supplement is cheap and widely available, which makes casual permanent use more likely. - The branded Rejuvant formulation is not identical to every generic Ca-AKG product. - Ongoing RCTs may clarify the category, but until they report results, the human claim remains unsettled. - A favorable biological-age screenshot can distract from better-established levers such as ApoB control, blood pressure, sleep, resistance training, and fitness. ## Solution **Treat Ca-AKG as a wait-for-human-RCT supplement category, not as a default longevity protocol.** A disciplined reader separates four claims before buying the product: Ca-AKG affects aging-related pathways in model systems; Ca-AKG improved frailty and survival measures in a mouse study; Rejuvant was associated with a lower methylation-age estimate in an uncontrolled customer cohort; and placebo-controlled human trials are testing whether the signal survives better design. The first two claims are real but preclinical. They justify interest. They don't justify a healthy-adult lifespan claim. The third claim is human but weakly controlled. It should be read as a case series around one commercial formulation and one methylation method, not as proof that Ca-AKG slowed human aging. The fourth claim is the one to watch. If a reader and clinician still discuss a personal Ca-AKG trial, the experiment needs a written endpoint and a stopping rule. The most conservative endpoint is no trial until ABLE or NCT07114536 reports results. A more intervention-minded plan would track ordinary clinical anchors such as sleep, training consistency, strength, blood pressure, body composition, glucose, ApoB, and symptoms, while treating any methylation-clock movement as a secondary signal. The weakest version is an indefinite supplement slot justified by "mitochondria," "epigenetics," or one younger biological-age report. The studied human protocols are reference protocols, not reader instructions. The Rejuvant paper used two tablets daily containing 1 g Ca-AKG plus vitamin A in the men's formulation or vitamin D in the women's formulation. ABLE is testing 1 g/day sustained-release Ca-AKG versus placebo for six months, followed by three months of observation. NCT07114536 is testing CaAKG versus placebo for 12 weeks in a small middle-aged and older adult cohort. Those designs describe what researchers are studying; they do not establish what any specific reader should take. > **⚠️ Supplement Boundary** > > Ca-AKG is sold as a dietary supplement, but longevity use is still an intervention claim. Pregnancy, breastfeeding, kidney disease, kidney-stone history, calcium-metabolism disorders, active cancer treatment, complex medication lists, eating disorders, and serious chronic disease all raise the bar for clinician review before adding it to a stack. ## Evidence **Evidence tier: Mechanistic / animal model.** The best direct longevity evidence is mammalian but preclinical. The human evidence is a methylation-clock case series and registered trials without posted efficacy results. The mouse paper is the serious starting point. Asadi Shahmirzadi and colleagues fed calcium alpha-ketoglutarate to middle-aged C57BL/6 mice beginning at 18 months. Female mice showed significant increases in median and late-life survival; male mice trended in the same direction without statistical significance. Frailty improved in both sexes, with reported reductions of about 46% in females and 41% in males. That is a meaningful preclinical signal because it began in midlife and measured morbidity, not only survival. The human marketing claim comes mainly from Demidenko and colleagues' 2021 Rejuvant paper. The authors analyzed 42 self-reported healthy customers who had baseline and follow-up saliva methylation tests after four to ten months of use, averaging about seven months. The reported mean reduction in the biological-age estimate was roughly eight years. The study matters because it is the public source behind the claim readers see. Its limits matter more: no placebo arm, no randomization, self-selected customers, one commercial product, one methylation test, lifestyle self-report, and no clinical outcomes. ABLE is the trial that should discipline the category. The published protocol describes a single-center, randomized, double-blind, placebo-controlled trial of 1 g/day sustained-release Ca-AKG versus placebo in 120 healthy adults aged 40 to 60 whose DNA-methylation age is higher than chronological age. The primary endpoint is change in the median of four blood-based methylation clocks, with secondary measures including inflammatory and metabolic blood markers, handgrip strength, leg-extension strength, arterial stiffness, skin autofluorescence, DXA body composition, and aerobic capacity. A 2025 recruitment paper confirmed the study design and recruitment feasibility; it did not report efficacy. NCT07114536 adds a smaller parallel signal. The ClinicalTrials.gov record describes a randomized, double-blind, placebo-controlled trial in generally healthy adults aged 40 to 75, with estimated enrollment of 30, 12 weeks of CaAKG versus placebo, and PhenoAge as the primary outcome. As of June 7, 2026, the record is active, not recruiting, and no results are posted. > **⚠️ Hype Check** > > The honest claim is not "Ca-AKG reduces human age by eight years." It is "Ca-AKG has a real mouse healthspan signal and an uncontrolled human methylation-clock case series; placebo-controlled human trials are still needed to decide whether the signal is real, durable, and clinically meaningful." ## How It Plays Out A 55-year-old sees Rejuvant marketed with the eight-year biological-age claim. The disciplined reading starts with the study design. Forty-two self-selected users and a proprietary methylation test are enough to generate interest, not enough to establish benefit. The next question is whether a placebo-controlled trial has confirmed the result. At present, that answer is no. A 62-year-old already lifting, walking, sleeping well, managing ApoB and blood pressure, and spending $40 per month on Ca-AKG because it is cheap may be making a low-cost bet. The practical risk is not usually the price. It is that the supplement becomes permanent without a defined reason to continue. Cheap interventions are still interventions. A clinic adds Ca-AKG to a standard "longevity starter stack" beside metformin, urolithin A, spermidine, NAD+ precursors, and creatine. The red flag is not any one molecule. It is the absence of hierarchy. Creatine, protein adequacy, and resistance training have clearer functional evidence for many adults than Ca-AKG. A serious plan can explain why this product belongs ahead of, or behind, those lower-drama basics. A researcher reads ABLE differently from a consumer. The trial is not trying to prove immortality. It is testing whether a cheap metabolite supplement can move DNA-methylation age and related physiological measures in biologically older middle-aged adults. A positive result would raise the category's status. A null result would not erase the mouse data, but it would sharply weaken the retail longevity claim. ## Consequences **Benefits.** Ca-AKG gives the reader a useful case study in evidence-tier discipline. It is biologically plausible, inexpensive, accessible, and backed by a mammalian frailty-and-survival paper. It is also being tested in placebo-controlled human trials rather than living only in marketing copy. That makes it more serious than many stack ingredients. The category also teaches the right relationship to biological-age tests. A methylation-clock result can be a research endpoint. It can also become a commercial shortcut. Ca-AKG forces the reader to ask whether the clock changed, whether the change is reproducible, whether ordinary clinical markers moved, and whether any of that predicts preserved function. **Liabilities.** The main liability is overclaiming. The Rejuvant paper's average methylation-age movement is often repeated as if it were a clinical result. It isn't. The study did not show fewer diseases, better function, lower mortality, or durable healthspan gain. It showed movement in one methylation-age estimate among selected customers taking one formulation. The second liability is stack creep. Ca-AKG is cheap enough to add and plausible enough to defend. That makes it exactly the kind of product that survives every audit because no single line item feels worth removing. A rational stack needs the opposite discipline: the easiest products to keep indefinitely are the ones that need the clearest stopping rules. The third liability is product substitution. "Ca-AKG" is not one controlled object in the market. Rejuvant's timed-release Ca-AKG plus vitamins, ABLE's sustained-release study product, and generic calcium alpha-ketoglutarate powders or capsules may differ in formulation, release profile, quality, and co-ingredients. A study of one product should not be silently generalized to all of them. The practical consequence is conservative: Ca-AKG is worth watching and may be worth a bounded clinician discussion for supplement-tolerant adults, but it is not a foundation intervention. Keep the foundations first, wait for human RCT readouts, and do not let one methylation-clock claim carry more weight than the evidence can hold. ## Sources - Asadi Shahmirzadi, Azar, Danielle Edgar, Chia-Ying Liao, et al. "Alpha-Ketoglutarate, an Endogenous Metabolite, Extends Lifespan and Compresses Morbidity in Aging Mice." *Cell Metabolism* 32, no. 3 (2020): 447-456.e6. https://doi.org/10.1016/j.cmet.2020.08.004 - Demidenko, Oleksandr, Diogo Barardo, Valery Budovskii, 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* 13, no. 22 (2021): 24485-24499. https://doi.org/10.18632/aging.203736 - Sandalova, Elena, Jing Goh, Zhen Xian Lim, et al. "Alpha-ketoglutarate supplementation and BiologicaL agE in middle-aged adults (ABLE): Intervention study protocol." *GeroScience* 45 (2023): 2897-2907. https://doi.org/10.1007/s11357-023-00813-6 - Sandalova, Elena, et al. "Recruitment evaluation of a gerotherapeutic randomized controlled trial testing alpha-ketoglutarate in biologically older, middle-aged adults (ABLE)." *Experimental Gerontology* (2025). https://pubmed.ncbi.nlm.nih.gov/40819772/ - U.S. National Library of Medicine. "NCT05706389: Does Alpha-ketoglutarate Supplementation Lower BiologicaL agE in Middle-Aged Adults?" ClinicalTrials.gov. https://clinicaltrials.gov/show/NCT05706389 - U.S. National Library of Medicine. "NCT07114536: Evaluation of the Efficacy of Calcium alpha-Ketoglutarate in Improving Human Aging." ClinicalTrials.gov. https://clinicaltrials.gov/study/NCT07114536 - Chin, Riekelt M., X. Feng, and J. R. Houtkooper, et al. "The Metabolite alpha-Ketoglutarate Extends Lifespan by Inhibiting ATP Synthase and TOR." *Nature* 510 (2014): 397-401. https://doi.org/10.1038/nature13264 ## Medical and Legal Boundary This entry is a reference, not medical advice. It describes published evidence, regulatory status, and common clinical practice patterns. It does not diagnose, prescribe, or replace a clinician's judgment for a specific person. Ca-AKG is sold as a dietary supplement, but supplement status does not make it appropriate for every reader. People who are pregnant or breastfeeding, under 18, over 70, managing kidney disease, kidney stones, calcium-metabolism disorders, active cancer, major chronic disease, eating-disorder history, complex medication lists, or planned surgery should discuss any Ca-AKG use with a qualified clinician. Stop and seek qualified care for new gastrointestinal symptoms, abnormal fatigue, flank pain, urinary changes, allergic symptoms, or any symptom that began after starting a supplement. --- - [Next: Low-Dose Tadalafil (Off-Label Longevity Use)](tadalafil-longevity-use.md) - [Previous: Senolytics (Dasatinib + Quercetin, Fisetin)](senolytic-cocktails.md)