Ca-AKG vs NMN: Which Longevity Supplement in 2026?

Last updated: November 1, 2026 · Originally published: July 31, 2026 · By Eternal Elixir Editorial

Quick answer: If you are buying one, start with NMN. It has the stronger human evidence: placebo-controlled trials in adults show it raises blood NAD+, and our 500mg capsule sits inside the 250mg to 2,000mg daily range those trials have tested. Ca-AKG makes more sense as a second addition than a first buy. Its best results come from mice, the human data so far are uncontrolled or observational, and our 500mg capsule is half the 1,000mg daily dose the human studies used. Our pick is Eternal Elixir NMN 500mg: one capsule a day, 90 capsules for $59.99, or $0.67 a day, dispatched in 1 business day.

Eternal Elixir makes both products compared here, and NMN 500mg is our pick, so read our view with that in mind. Both cost the same, so price plays no part in the recommendation. The studies are listed in full at the end, competitor prices were read from each product’s own page in September 2026 and are linked, and we have not lab-tested any product.

Ca-AKG vs NMN at a glance

Here are the two side by side as we sell them. Prices are as of Sep 2026.

Price, capsule count and serve are identical. What separates the two is how each one works and how much of its evidence comes from people rather than mice.

What Ca-AKG is and how it works

Ca-AKG is the calcium salt of alpha-ketoglutarate (AKG), which keeps the molecule stable in a capsule. Your body already makes AKG. It is one of the intermediates of the Krebs cycle, the chain of reactions inside mitochondria that turns food into usable energy, and it also shuttles nitrogen between amino acids.

Researchers took an interest because AKG appears to fall with age. The authors of the main mouse study cite a report that plasma AKG drops about tenfold between the ages of 40 and 80. In cells, AKG is also used by a family of enzymes that remove methyl groups from histones, the proteins DNA wraps around, which is why it comes up in talk about epigenetic or “biological” age. No human study has yet shown that a Ca-AKG supplement changes the activity of those enzymes in people.

Ca-AKG often sits beside autophagy supplements in longevity stacks. Our breakdown of how Ca-AKG compares with spermidine covers that pairing, and the Ca-AKG benefits and dosage guide goes further on timing and stacking.

What NMN is and how it works

NMN is nicotinamide mononucleotide. Cells convert it into NAD+ (nicotinamide adenine dinucleotide), a coenzyme that many enzymes need for energy metabolism, including the sirtuins linked to cell maintenance. NMN sits one step from NAD+ in the salvage pathway, the route cells use to recycle NAD+ building blocks.

NAD+ falls with age in people as well as animals. A Sydney study of healthy adults across a wide age range found plasma NAD+ declined with age. That decline is the reason NAD+ precursors exist as a category. NMN is not NAD+ itself, and our guide explains why NMN and NAD+ are not interchangeable. For the age curve in more detail, see how NAD+ changes as you get older.

NMN is not the only precursor. Nicotinamide riboside (NR) feeds the same pathway one step earlier and has placebo-controlled trials of its own. Our summary of what the NR research shows and the NMN vs NR comparison cover where it fits. For amounts and timing on NMN itself, use the NMN dosage guide.

The evidence: what the studies show for each

This is where the two part company. NMN has a set of placebo-controlled human trials behind its main effect. Ca-AKG has a strong mouse study and early human signals that nobody has yet tested against a placebo.

The strongest case for Ca-AKG. The 2020 mouse study was well run: two separate cohorts, blinded frailty scoring across 31 measures, and a start in late middle age rather than youth. The drop in frailty was larger than the lifespan gain, which is why the authors call the result a compression of morbidity, meaning more of life spent in good health. The human signals point the same way. But the Rejuvant study had no placebo group and drew on customers who had chosen the product, and the 2026 survey can only show an association. Several authors of the mouse and Rejuvant papers hold shares in, or advise, Ponce de Leon Health, the company that sells Rejuvant. None of that makes the findings wrong. It does make the ABLE trial, the first placebo-controlled test of Ca-AKG on epigenetic age, the result worth waiting for.

What the NMN trials do and don’t show. They show that NMN taken by mouth raises blood NAD+ in adults and was well tolerated at the doses tested. Some found modest gains in walking tests or aerobic markers, and the muscle results in older men were only nominally significant. None measured lifespan, and none of the pooled trials ran past 24 weeks. The Yi trial’s authors include employees of Abinopharm and ABA Chemicals, so sponsorship questions apply here too.

What neither has shown. No study has shown that either supplement extends human life. No trial has compared Ca-AKG with NMN head to head, and none has tested the two together. Any claim that goes further than the table above is marketing.

Our serve compared with the doses in the studies

NMN 500mg. One capsule gives 500mg. That is double the 250mg a day that raised blood NAD+ in the 12-week trial in older men, and it sits inside the 250mg to 2,000mg range pooled in 2026. It is below the 600mg and 900mg arms that produced the highest blood NAD+ and the longest walking distances in the Yi trial. So 500mg is a well-studied daily serve, but not the top of the range. Our guide to whether one 500mg capsule is enough goes through each trial.

Ca-AKG 500mg. One capsule gives 500mg of calcium alpha-ketoglutarate. That is half the 1,000mg a day used in the Rejuvant study and the ABLE trial. The mouse dose was a share of the diet (2%), which does not convert neatly into a human serve. Our label says one capsule daily. Matching the 1,000mg studied in people would take two capsules, which goes beyond the label direction, so talk to your doctor before you do that. The human studies also used sustained-release or delayed-release tablets. Ours is a capsule, and our label makes no delayed-release claim.

What Ca-AKG and NMN cost in Australia

Chemist Warehouse’s site search listed no Ca-AKG supplement when it was checked in September 2026, so most Australians buy Ca-AKG online. NMN is easier to find, including 30-capsule pharmacy packs. Here is how our two compare with a Ca-AKG capsule sold into Australia, a pharmacy NMN and a drink that contains both. Prices are as of Sep 2026 and were read from each product’s own page.

Per 500mg, our Ca-AKG costs $0.67 against $0.88 for Naturecan, but Naturecan’s two-capsule serve gives the full 1,000mg the human studies used. Bioglan’s pack costs less up front, though at $1.42 a day it is more than twice our price per 500mg and holds 30 capsules. Tmrw puts NMN and a 1,000mg Ca-AKG dose in one scoop alongside 86 other ingredients, for about $4.30 a day. If these two actives are all you want, two of our capsules cost $1.33 a day.

Our Tmrw and AgeMate comparison covers the drink in more detail. For the wider market, see our Ca-AKG products compared and the guide to NMN brands sold in Australia.

Which should you choose?

Start with what you want the supplement to do, then decide how much human evidence you need before you pay for it.

NMN suits you if

• You want the option with placebo-controlled human trials behind its main effect.
• Your interest is NAD+ and energy metabolism, a pathway that human blood studies show declining with age.
• This is your first longevity supplement and you would rather begin where the evidence is clearer.
• You already take Ca-AKG and want a separate second pathway.

NMN is not for you if

• You expect to feel it within days. It is not a stimulant, and the trials measured change over weeks.
• You want data on use beyond six months. The pooled trials stop at 24 weeks.
• You are pregnant, breastfeeding or under 18. The trials enrolled adults only.

Ca-AKG suits you if

• You already take an NAD+ precursor and want to add a different mechanism instead of doubling up.
• You follow the healthy-ageing research on AKG and accept that the human evidence is early.
• You want a low daily cost. One of our capsules is $0.67.

Ca-AKG is not for you if

• You want placebo-controlled proof in people before you buy. That answer rests on the ABLE trial.
• You want the full 1,000mg studied dose in the label serve. Naturecan’s two-capsule serve and Tmrw’s scoop both give 1,000mg.
• You have been told to limit calcium. Ca-AKG is a calcium salt, so ask your doctor first.

Can you take Ca-AKG and NMN together?

Yes. They act on separate pathways, so taking both adds a mechanism rather than doubling one, which is what happens if you pair NMN with NR. Some products already combine them: Tmrw’s drink lists both. No trial has tested the pair, though, so the case for combining them rests on how each one works, not on a combined result.

A simple routine is one NMN capsule and one Ca-AKG capsule with breakfast. Our NMN label suggests the morning, and the Ca-AKG label says one capsule daily. One bottle of each comes to $119.98, which clears the $100 free-shipping threshold, and 90 capsules of each last three months at $1.33 a day.

If you also want spermidine and pterostilbene, the Cellular Longevity Stack ($139.99) already contains NMN 500mg, Spermidine 10mg and Trans-Pterostilbene 500mg. Add Ca-AKG to it on its own rather than buying a second NMN bottle. For the spermidine side, read our guides to spermidine benefits, taking spermidine with NMN and spermidine vs NMN, or go straight to Spermidine 10mg. The longevity stack guide maps out combinations by goal and budget.

Side effects and safety

NMN was well tolerated in the trials above. The 2026 pooled analysis of 15 randomised trials found no increase in adverse events and no rise in liver enzymes at 250mg to 2,000mg a day for up to 24 weeks. Some pharmacy NMN labels, Bioglan’s among them, say not to use it for more than 12 weeks. Our label says one capsule daily.

Ca-AKG has far less human safety data than NMN, and the largest placebo-controlled trial, ABLE, has not yet reported its results. Neither supplement has been studied in pregnancy, breastfeeding or under-18s, so avoid both in those cases. If you take prescription medicines or have a medical condition, talk to your doctor before you start either one.

Ca-AKG vs NMN: frequently asked questions

Is Ca-AKG better than NMN?

Not on current evidence. NMN has placebo-controlled human trials showing it raises blood NAD+, while Ca-AKG’s strongest results are in mice. Eternal Elixir NMN 500mg is our pick as a first buy, and Eternal Elixir Ca-AKG 500mg is the one to add second.

Or NMN with resveratrol and TMG: NAD+ and Methylation Stack · $139.99

Does Ca-AKG actually work?

In mice, Ca-AKG started in late middle age lowered frailty scores and extended lifespan in females. In people, it is unproven. A study of 42 Rejuvant users reported an 8-year drop in epigenetic age but had no placebo group, and a 2026 survey found a smaller association that was significant only for a delayed-release product. The placebo-controlled ABLE trial should give the first proper answer.

Is NMN toxic to the liver?

The trials so far found no sign of liver harm at the doses tested. A 2026 pooled analysis of 15 randomised trials found that NMN at 250mg to 2,000mg a day, taken for 14 days to 24 weeks, did not raise the liver enzymes ALT and AST or increase adverse events compared with control. Longer use has not been studied, so if you have a liver condition or take medicines, talk to your doctor first.

What works better than NMN?

We know of no head-to-head human trial in which another supplement beat NMN. NR, the other main NAD+ precursor, raised NAD+ in its own placebo-controlled trial in middle-aged and older adults. Which suits you depends on dose, price and which trials you find more convincing, and our NMN vs NR guide sets them side by side. We sell both: Pure NR 500mg and NMN 500mg.

Can I take Ca-AKG and NMN at the same time?

Yes. They work through separate pathways, so one capsule of each with breakfast is a simple routine. No trial has tested the combination. If you take prescription medicines, check with your doctor first.

How long do Ca-AKG and NMN take to work?

Neither works like a stimulant. In the Yi trial, blood NAD+ and walking distance had both improved by day 30 and were still higher at day 60. The Ca-AKG studies in people ran for 4 to 10 months. Give either one at least three months of daily use before you judge it. Our timeline for how long NMN takes to work breaks this down.

Which is better value in Australia?

They cost the same: $59.99 for 90 capsules, or $0.67 a day each. One bottle of each comes to $119.98 and ships free because the order is over $100. Two bottles of the same product save 10%, so two bottles of NMN cost $107.98.

Add TMG 2000mg to your NMN · $44.99

Should I take NMN in the morning?

Our NMN label says one capsule daily, preferably in the morning. No trial has settled the best time of day, so pick a time you will remember and keep to it.

The verdict: Ca-AKG or NMN?

Our pick: Eternal Elixir NMN 500mg. It has the stronger human evidence, its 500mg capsule sits inside the range the trials tested, and a 90-capsule bottle works out at $0.67 a day, dispatched in 1 business day.

Add Eternal Elixir Ca-AKG 500mg if you want a second pathway and accept that its human evidence is early. One capsule is half the dose used in the human studies, so weigh that before you buy. When the ABLE trial reports, this comparison may change.

Browse the full Eternal Elixir range.

Sources

• 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;32(3):447-456.e6. PubMed 32877690
• 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 (Albany NY). 2021;13(22):24485-24499. PubMed 34847066
• 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;25(6):e70517. PubMed 42166733
• Sandalova E, Goh J, Lim ZX, et al. Alpha-ketoglutarate supplementation and BiologicaL agE in middle-aged adults (ABLE): intervention study protocol. GeroScience. 2023;45(5):2897-2907. PubMed 37217632
• Lu JK, Wang W, Chew YE, et al. Optimizing accelerometer implementation in a gerotherapeutic trial: feasibility, adherence, and operational insights of ABLE. PLOS Digital Health. 2026;5(9):e0001691. PubMed 42789532
• Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience. 2023;45(1):29-43. PubMed 36482258
• Igarashi M, Nakagawa-Nagahama Y, Miura M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. 2022;8(1):5. PubMed 35927255
• Liao B, Zhao Y, Wang D, et al. Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. Journal of the International Society of Sports Nutrition. 2021;18(1):54. PubMed 34238308
• Yang W, Huang J, Tang Z, Chen C, Sun Y. Safety and metabolism-related outcomes of oral nicotinamide mononucleotide supplementation in adults: a systematic review and meta-analysis. Nutrients. 2026;18(14):2251. PubMed 42514320
• Clement J, Wong M, Poljak A, Sachdev P, Braidy N. The plasma NAD+ metabolome is dysregulated in “normal” aging. Rejuvenation Research. 2019;22(2):121-130. PubMed 30124109
• Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications. 2018;9(1):1286. PubMed 29599478
• Product pages read in September 2026: Naturecan Ca-AKG and Naturecan delivery, Bioglan NMN 500 at Chemist Warehouse and Tmrw Daily.
• Eternal Elixir product pages and labels: NMN 500mg and Ca-AKG 500mg.