A four-carbon intermediate of the citric acid cycle, stabilised in an anhydrous enol form with vitamin C so it survives long enough to be swallowed. Ordinary oxaloacetate decomposes rapidly in solution.
Oxaloacetate is sold on the basis that it shifts the cellular NAD+ to NADH ratio in a way that mimics calorie restriction, an idea supported by studies in nematodes and mice. The human evidence is small and preliminary: pilot trials in chronic fatigue syndrome and long COVID reported improvements in fatigue scores, mostly open-label or with small control groups, and there are early studies in Alzheimer's disease measuring brain metabolism rather than cognition. Nothing has been replicated at scale, doses in trials are high, and the compound is expensive. It also has essentially no long-term human safety data, which matters for something being taken daily on a longevity rationale.
Sold as
Capsule (anhydrous enol form with vitamin C), Powder
Standardised to
Milligrams of anhydrous enol-oxaloacetate; stabilisation is what distinguishes the supplement from the unstable metabolite — a product without this marker may not resemble what was studied.
Also known as
Anhydrous enol-oxaloacetate, benaGene, OAA
Regulation: Sold as a dietary supplement in the US with no pre-market efficacy review, while being investigated in registered trials for fatigue conditions. No regulator has approved it for anything.
What the research used
The amounts, forms and durations published trials of Oxaloacetate actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Chronic fatigue and long COVID pilot studies
500–2000 mg
Not enough
Capsule, divided doses · 6 weeks
Doses in small pilot studies, several open-label or with historical comparison groups, and conducted with involvement from the supplement manufacturer.
Studied for Alzheimer's disease metabolic studies
100 mg
Not enough
Twice daily · 1 month
A very small study measuring brain glucose metabolism and blood flow rather than cognitive outcomes. Fewer than twenty participants.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
When it was taken
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
🔀Split through the day
Not enough
Divided across the day in trials because the compound is cleared quickly. No timing comparison has been tested.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
The evidence in depth
Best supported: Not enough
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
A very small study measured brain glucose metabolism in people with Alzheimer's disease. It did not measure cognition meaningfully and is far too small to support anything.
Not enough evidence. Not enough human research to say anything useful yet.
Lifespan extension in nematodes and metabolic effects in mice underpin the calorie-restriction-mimetic framing. No human ageing outcome has been measured.
Not enough evidence. Not enough human research to say anything useful yet.
No source is attached to this association yet, so it is rated not enough evidenceby default. It is listed because people commonly ask about it — not because there is evidence for it.
Pilot studies in chronic fatigue syndrome and post-viral fatigue report improved fatigue scores. They are small, largely open-label, involve the manufacturer, and use an outcome that responds strongly to expectation.
What may be going on: Oxaloacetate is proposed to shift the cytosolic NAD+ to NADH ratio, activating AMPK and mimicking aspects of calorie restriction. This has been shown in model organisms rather than in people.
Not enough evidence. Not enough human research to say anything useful yet.
Clinical trial · Alzheimer's & dementia : the journal of the Alzheimer's Association · 2021 · PMID 32715609
Deep research mode adds each paper’s own conclusion and stated limitations.
Things to know
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Worth knowing
Preliminary studies with manufacturer involvement
The fatigue findings come from small pilot studies, several without proper blinding or control, conducted with the involvement of the company selling the compound. Fatigue is among the most placebo-responsive outcomes in medicine, which makes uncontrolled designs particularly unreliable here.
Worth knowing
No long-term safety data
Published human exposure runs to weeks. Daily long-term use on a longevity rationale extends far beyond anything that has been studied, in a compound that intervenes directly in central energy metabolism.
Interaction
Possible effects on blood glucose
Interacts withInsulin, sulfonylureas, metformin
A compound acting on gluconeogenesis and the citric acid cycle could plausibly affect blood glucose. This has not been characterised in people on diabetes medication, which is a gap rather than a reassurance.
Avoid
No data in pregnancy or childhood
There is no safety data in pregnancy, breastfeeding or children, and no reason to consider it in those groups.