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The most searched-for practical question about Ca-AKG is also the one most websites refuse to answer clearly. "Consult a healthcare provider" is the standard evasion. That is fine as far as it goes, but it does not tell you what dose the actual clinical trials use — and that is what you probably want to know.
Every longevity study on Ca-AKG has converged on roughly the same dose. This article walks through where that number comes from, how the delayed-release formulation changes the picture, and what happens above and below it. For the wider evidence overview, see our pillar: calcium alpha-ketoglutarate — the complete evidence-based guide. Every citation links back to a paper page in our Ca-AKG Data Center.
What dose of Ca-AKG do the trials actually use?
Four human studies matter for this question, and they converge on a narrow dose range.
| Study | Population | Dose | Duration | Formulation |
|---|---|---|---|---|
| Filip 2007 (bone health) | Postmenopausal women with osteopenia | 6 g/day | 24 weeks | Standard Ca-AKG |
| Demidenko 2021 (Rejuvant retrospective) | Health-optimising middle-aged adults | 1,000 mg/day | ~7 months average | Delayed-release Ca-AKG |
| Sandalova 2023 (ABLE trial protocol) | Middle-aged adults | 1,000 mg/day | 6 months | Delayed-release Ca-AKG |
| NCT07114536 (Chinese RCT) | Adults aged 40–75 | 1–2 g/day (source discrepancy) | 12 weeks | Standard Ca-AKG |
The rough consensus for longevity outcomes is 1,000 mg per day. The bone health study used substantially more (6 g/day) — reflecting the different indication and the fact that the primary endpoint was a bone resorption marker rather than a systemic ageing marker [6].
How much Ca-AKG should you take?
For longevity purposes, 1,000 mg per day is the trial-anchored answer.
Two caveats matter. First, this is not a personalised recommendation — no trial has established that 1,000 mg is optimal, only that it is the dose the human studies have used. It could be that 500 mg works equally well and no-one has tested it. It could be that 2,000 mg would work better and no-one has tested that either. What we know is that 1,000 mg per day is where the human data lives.
Second, the dose is form-specific. The 1,000 mg trials all used the delayed-release Rejuvant formulation. Standard immediate-release Ca-AKG at the same nominal dose appears to produce a substantially smaller effect — and this brings us to the formulation question.
Where does the 1,000 mg number come from?
Two lineages.
The direct human lineage traces to the 2021 Rejuvant retrospective in Aging, which analysed 42 supplement users who had taken 1,000 mg/day of delayed-release Ca-AKG for an average of 7 months and had done TruAge DNA methylation age testing before and after [2]. The reported average biological age reduction of approximately 8 years generated the headline that drove modern interest in Ca-AKG as a longevity supplement.
The trial lineage traces to the ABLE study protocol published in 2023 in GeroScience, which tests the same 1,000 mg/day delayed-release dose in a randomised, placebo-controlled trial [3]. The trial deliberately used the same dose as the Rejuvant retrospective so that a positive result would validate that finding.
Both lineages converge on 1,000 mg per day of delayed-release Ca-AKG. That is where the number comes from — not from a dose-response study, but from the dose the most-cited retrospective happened to use.
Does the delayed-release form change the dose?
No — but it changes the effect substantially.
In the 2026 Pabis Aging Cell cohort of 4,260 exceptionally healthy adults, delayed-release Ca-AKG was associated with a biological age approximately 1.8 years lower than expected. Standard immediate-release Ca-AKG at similar total daily doses showed an effect roughly 8 times smaller and did not reach statistical significance [5].
Practically: 1,000 mg of delayed-release Ca-AKG is not equivalent to 1,000 mg of standard Ca-AKG. Whether a higher dose of standard Ca-AKG (say 2,000 mg/day) would compensate for the formulation gap is unknown — no head-to-head trial has been run. For the fuller walkthrough of the formulation question, see Ca-AKG vs free AKG. For the wider forms comparison, AKG forms explained.
What does the mouse dose translate to for a human?
The mouse-to-human translation is one of the most misrepresented numbers in the Ca-AKG conversation.
The 2020 Buck Institute mouse lifespan study used food-incorporated Ca-AKG at 2% by weight of the chow [1]. Mice ate roughly 4 to 5 grams of chow per day, so each mouse received approximately 80 to 100 mg of Ca-AKG daily.
Scaled to a 70 kg human by body-surface-area allometric conversion — the standard method regulators use — that translates to roughly 400 to 500 mg per day. Meaningfully lower than the 1,000 mg human trials use.
Two things to note. First, body-surface-area conversion is a rough approximation, not a validated pharmacokinetic tool for Ca-AKG specifically. Second, the mice received Ca-AKG continuously in food, spread across every meal and every hour. Human capsule dosing is discrete. Whether the pharmacokinetic profile difference matters for the biological effect is unknown.
For a full paper-by-paper walkthrough of the mouse study, including the dose calculation, see the Shahmirzadi 2020 deep-dive.
Should you split the dose or take it all at once?
No trial has directly tested single vs split dosing of Ca-AKG. The available human studies have used both approaches:
The Rejuvant retrospective and the ABLE trial use single-dose capsules taken once daily. This reflects the delayed-release formulation, which is specifically designed for gradual release across several hours — mimicking a split-dose profile from a single capsule.
The Chinese trial NCT07114536 splits its dose across the day. The Filip 2007 bone health trial used a split-dose regime.
The practical takeaway: if you are using delayed-release Ca-AKG, single daily dosing is what the trials use and is what the formulation is designed for. If you are using standard immediate-release Ca-AKG, splitting the daily dose across two or three servings may better approximate the continuous exposure profile that produced the mouse effects — but no trial has proven this matters.
For the specific timing question — with food, empty stomach, morning vs evening — see when to take Ca-AKG.
How long before you see an effect?
Longer than most people expect.
The Rejuvant retrospective measured biological age reduction after an average of 7 months of continuous supplementation [2]. The ABLE trial measures its primary endpoint at 6 months [3]. The Chinese trial measures at 12 weeks — the shortest of the longevity-focused studies, and one reason its results will be interesting to compare against the longer protocols [4].
For biological age endpoints, plan on 6 to 12 months of continuous supplementation before expecting a measurable shift. Anyone marketing Ca-AKG with promises of "results in weeks" is running ahead of the evidence.
The bone health effect (CTX reduction) in the Filip 2007 trial was detectable at 24 weeks [6]. Similarly slow.
What is the maximum safe dose?
No trial has exceeded approximately 2 g/day for longevity outcomes, and no trial has established a formal upper limit.
The historical clinical use of Ca-AKG and related compounds — catalogued in a 2017 review in Archivum Immunologiae et Therapiae Experimentalis — includes higher doses in specific clinical contexts [7]. Ca-AKG has been used at multi-gram doses in patients on haemodialysis and in some post-surgical recovery protocols under medical supervision. But these are indicated clinical uses, not longevity supplementation, and they are not directly comparable.
For self-directed longevity supplementation, the honest position is: doses beyond 2 g/day exceed the range where any published human trial has established a safety and efficacy profile. Not necessarily unsafe — just uncharacterised.
Special considerations — calcium load and interactions
Every 1 g of Ca-AKG delivers approximately 200 mg of elemental calcium. Practical implications:
1,000 mg/day Ca-AKG adds ~200 mg calcium — roughly 15 to 20% of the daily calcium recommendation for most adults. Trivial for someone who does not otherwise supplement.
2,000 mg/day Ca-AKG adds ~400 mg calcium — enough to matter if you already take a separate calcium supplement or eat a calcium-fortified diet. The tolerable upper intake for calcium is 2,500 mg/day for most adults, and pushing near it long-term is associated with kidney stone risk in some people.
Kidney stone history. Anyone with a personal or family history of calcium oxalate or calcium phosphate stones should discuss any added calcium source with their doctor before starting.
Drug interactions. Calcium can interfere with the absorption of certain medications — some thyroid hormones (levothyroxine), tetracycline-class antibiotics, some bisphosphonates, and iron supplements. Separate Ca-AKG dosing from these medications by at least 4 hours.
Untested populations. Ca-AKG has not been formally tested in pregnancy, breastfeeding, or in children. It has not been tested for drug interactions in any systematic way. Anyone on chemotherapy, on narrow-therapeutic-index medications, or with significant kidney disease should consult a doctor before starting.
The full safety walkthrough — including populations to avoid, adverse events reported in trials, and honest caveats about the missing long-term data — lives in Ca-AKG side effects and safety profile. For how Ca-AKG combines with other longevity supplements, see Ca-AKG stacking. For the "which product should I actually buy" question, see the best Ca-AKG supplement guide. For basic beginner context if you have arrived here without background, what is Ca-AKG.
Bottom line
The trial-anchored dose for Ca-AKG in longevity contexts is 1,000 mg per day. Every human longevity study on the compound has used approximately this dose. The Rejuvant retrospective, the ABLE trial, and the emerging Chinese trial all cluster in the 1 to 2 g/day range.
Formulation matters at least as much as dose. Delayed-release Ca-AKG at 1,000 mg/day appears to outperform standard-release Ca-AKG at the same total daily dose by a factor of roughly 8 in the largest available cohort data. Whether higher doses of standard-release compensate for the formulation gap is unknown.
Plan on 6 to 12 months of continuous supplementation for biological age endpoints. Doses above 2 g/day exceed the range where any published human trial has characterised safety and efficacy. Factor the calcium load (~200 mg per 1 g Ca-AKG) into your daily calcium total, especially if you already supplement.
Everything else is in the Ca-AKG pillar.