AICAR sits in research-vendor catalogues alongside the peptides, but it is not a peptide at all — it is a small-molecule nucleoside, a synthetic analogue of cellular AMP. Its entire research relevance flows from a single target: AMP-activated protein kinase (AMPK), the master energy sensor of the cell. Because switching AMPK on reproduces much of the molecular signature of physical exercise, AICAR has been labelled an "exercise mimetic" in the literature. This monograph covers what AICAR is, the AMPK mechanism that defines it, what the research record actually supports (largely preclinical), and what to demand of a vendor.
Chemical identity and structure.
AICAR (5-aminoimidazole-4-carboxamide ribonucleoside), also known as acadesine, is a nucleoside with the molecular formula C₉H₁₄N₄O₅ and a molecular weight of approximately 258.2 g/mol. It is not a peptide and has no amino-acid sequence. AICAR is a prodrug: once inside the cell it is phosphorylated by adenosine kinase to its monophosphate form, ZMP, which is the actual active species and a structural mimic of 5′-AMP.
Mechanism of action.
ZMP binds the gamma (γ) regulatory subunit of AMPK at the site normally occupied by AMP, producing allosteric activation and promoting phosphorylation of Thr172 on the α-subunit by the upstream kinases LKB1 and CaMKKβ. Activated AMPK acts as a cellular fuel gauge: it switches on catabolic, ATP-generating pathways (glucose uptake via GLUT4 translocation, fatty-acid oxidation, mitochondrial biogenesis through PGC-1α) and switches off anabolic, ATP-consuming ones. This pattern overlaps substantially with the adaptations triggered by endurance exercise, which is the basis of the "exercise mimetic" framing. AICAR is not a receptor agonist; its effects are distributed across cellular metabolism through AMPK.
Research applications and the evidence base.
AICAR is a long-standing laboratory tool for interrogating AMPK signalling. Published work spans cellular metabolism, exercise physiology, mitochondrial function, and disease modelling for type 2 diabetes, obesity, and cardiovascular disease. Oncology studies report that AICAR decreased angiogenesis and induced apoptosis in a retinoblastoma model, and pharmacology work describes Nrf2-mediated antioxidant effects and NLRP3 inflammasome inhibition in acute-pancreatitis liver injury. As acadesine, it has been studied clinically in cardiac-surgery ischaemia and in older haematology trials. Two honest caveats: most of the metabolic and "exercise-in-a-vial" claims rest on cell and animal models rather than human outcome data, and AICAR is prohibited in sport (WADA, metabolic-modulator class). It is not approved for human or veterinary use.
Human clinical trial data
In the RED-CABG randomized, double-blind, placebo-controlled trial by Newman et al. (2012), intermediate- to high-risk patients undergoing nonemergency on-pump coronary artery bypass surgery were randomized 1:1 to receive an acadesine infusion or placebo, beginning just before anesthesia induction (PubMed). The trial was stopped for futility after 3080 participants were randomized; the primary outcome occurred in 5.0% of the placebo group and 5.1% of the acadesine group, and acadesine did not reduce the composite of all-cause mortality, nonfatal stroke, or severe left ventricular dysfunction (PubMed). This perioperative infusion setting does not establish administration parameters for any other use.
Storage and handling.
Store lyophilized AICAR frozen at −20 °C. Avoid repeated freeze–thaw cycles.
Quality and COA considerations.
A meaningful COA should confirm identity by mass spectrometry (expected MW ~258 g/mol), purity by HPLC (≥98% is a reasonable benchmark for a defined small molecule), and — for any in-vivo or tissue-contact model — endotoxin. Because AICAR is a small molecule rather than a peptide, peptide-specific assays (e.g. sequence confirmation) do not apply; identity rests on mass and HPLC.
Research-use note: This monograph is an educational summary of the published research literature for AICAR (acadesine). AICAR is for laboratory and research use only, is not approved for human or veterinary use, is prohibited in sport, and nothing described above is a therapy or a usage recommendation. Nothing here is medical advice.