What it is
AICAR — 5-aminoimidazole-4-carboxamide ribonucleoside — is a nucleoside, not a peptide. It is chemically related to the building blocks of DNA and RNA, and the body makes it itself as an intermediate step in the synthesis of purines.
Once inside a cell it is phosphorylated into a molecule called ZMP. ZMP resembles AMP closely enough to activate AMPK, the enzyme that acts as a cell's low-fuel warning light. When AMPK switches on, the cell starts burning fat and pulling in glucose, and switches off the expensive business of building things. It is the same sensor that exercise activates, which is why an AMPK activator gets called an exercise mimetic.
The mechanism is not in dispute. What follows from it is.
The human record is large, and it is all about something else
This is the unusual entry in this library. Most compounds here have a thin human record; AICAR has a substantial one.
PubMed indexed 2,718 records for AICAR on 2026-09-11, of which 1,128 carry a human tag. Under its drug-development name, acadesine, a further 314 records exist, 145 of them human-tagged. ClinicalTrials.gov held six registrations naming AICAR and four naming acadesine on the same date.
Read those ten registrations and the picture is unambiguous:
| Study | Indication | N | Outcome |
|---|---|---|---|
| RED-CABG (NCT00872001, Merck) | Coronary artery bypass surgery | 3,080 | Terminated — futility |
| NCT00559624 (Advancell) | B-cell chronic lymphocytic leukaemia | 40 | Completed |
| NCT01813838 (GFM) | Myelodysplastic syndrome / AML | 5 | Terminated — renal toxicity |
| NCT00004314 (NCRR) | Lesch-Nyhan disease | 2 | Completed |
| NCT06845501 (CHU Saint-Étienne) | AICA-ribosiduria | 10 | Recruiting |
Heart surgery. Blood cancer. Two rare inherited disorders of purine metabolism. Not one study in the registry, and nothing in the published record, tests AICAR for endurance, fat loss, body composition or athletic performance — the only things it is sold for.
What happened when it was tested properly
RED-CABG is the trial that matters, and it is worth stating its result precisely, because it is the most complete answer this library has been able to give about any compound in its collection.
The Reduction in Cardiovascular Events by Acadesine in Patients Undergoing CABG trial was randomised, double-blind and placebo-controlled, run at 300 sites in 7 countries in intermediate- to high-risk patients with a median age of 66, and published in JAMA in July 2012 (2012;308(2):157-64). Participants received acadesine at 0.1 mg/kg per minute for seven hours, beginning just before anaesthesia, with the drug also added to the cardioplegic solution.
It was stopped early. A prespecified futility analysis indicated a very low likelihood of a statistically significant efficacious outcome, and enrolment halted at 3,080 of a projected 7,500 participants.
The primary endpoint — all-cause death, non-fatal stroke, or the need for mechanical support for severe left ventricular dysfunction through post-operative day 28 — occurred in 75 of 1,493 placebo patients (5.0%) and 76 of 1,493 acadesine patients (5.1%). The odds ratio was 1.01, with a 95% confidence interval of 0.73 to 1.41. The authors reported no differences in key secondary endpoints.
That is not an underpowered study or an ambiguous signal. A well-run trial of three thousand people found the drug did exactly nothing, and it had been designed on the back of an earlier meta-analysis that suggested it would work.
The safety item in the registry
One entry carries a recorded reason for stopping. NCT01813838, a phase 1/2 trial of acadesine in high-risk myelodysplastic syndrome and acute myeloid leukaemia run by the Groupe Francophone des Myélodysplasies, was terminated after five patients. The registry gives the reason in two words: renal toxicity.
Five patients is a small number and the population was seriously ill, so this is a signal rather than a finding. But it is the only recorded reason for stopping anywhere in the compound's registered record, and it exists.
Why the paper count is misleading
A reader who checks PubMed and finds 1,128 human-tagged records will reasonably conclude that AICAR is well studied in people. It is, but not in the way the number implies.
A substantial part of that literature concerns the AICAR the body makes itself. AICA-ribosiduria and related inherited enzyme deficiencies are defined by how much of the compound accumulates, and there is an active clinical literature on measuring it in patients — one of the registrations above, recruiting at Saint-Étienne, is a purine-supplementation study in exactly that population. Measuring a molecule in people is not the same as giving it to them.
This library has now documented that pattern three times: in LL-37, where nearly two thousand human papers sit beside no product at all; in the mitochondrial peptide MOTS-c, where the literature almost entirely measures the body's own peptide; and here. It is the single most common way a compound's evidence base gets overstated.
Where it stands
There is no approved medicine. Searches of DailyMed and Drugs@FDA on 2026-09-11 returned nothing under either name — a notable absence for a compound that reached phase 3 under a major pharmaceutical sponsor and has been in development since the late 1980s. What is sold is a research chemical.
For readers comparing it against the other non-peptides sold in this market, see SLU-PP-332, which occupies the opposite position — an almost empty literature and no human data at all — and the NNMT inhibitor sold as 5-amino-1MQ.