RESEARCH AND EDUCATION DISCLAIMER
This article summarizes published scientific research for educational purposes only. Level Up Peptides products are intended exclusively for laboratory research by qualified researchers and are not for human or veterinary use. Discussion of published animal or human studies does not recommend those uses or establish the safety or effectiveness of any product sold on this website. This article does not provide medical advice, dosing guidance, or administration instructions.
SUMMARY
AICAR, also called acadesine, is a small molecule used to investigate cellular metabolism. Much of its research concerns AMP-activated protein kinase, or AMPK, an enzyme involved in how cells respond to energy availability. Published studies include cell experiments, animal research, and human trials, with different findings across these settings. AICAR also produces effects outside AMPK signaling, so an experimental response cannot automatically be attributed to this single pathway. [1–5]
WHAT IS AICAR?
In this article, AICAR refers to AICA riboside, also known as acadesine. It is a nucleoside analogue rather than a peptide. Inside cells, it can be converted into a phosphorylated molecule called ZMP. Distinguishing the supplied compound from this intracellular derivative helps explain how researchers interpret its effects. [1,3]
WHY DO RESEARCHERS STUDY AMPK?
AMPK helps cells adjust their activity when energy availability changes. Researchers study this pathway to understand how cells regulate energy-consuming processes and fuel metabolism.
A foundational 1995 study examined AICAR in isolated rat liver cells. The investigators observed intracellular ZMP accumulation, AMPK activation, and reduced fatty-acid and sterol synthesis. ZMP could imitate aspects of the signal normally supplied by AMP, a molecule associated with cellular energy status. These experiments helped establish AICAR as a tool for investigating metabolic regulation. [1]
WHAT DID THE MOUSE ENDURANCE STUDY FIND?
A 2008 study by Narkar and colleagues investigated metabolic signaling and treadmill performance in mice. After four weeks of AICAR exposure, previously sedentary mice showed changes in metabolic gene expression and greater running endurance than controls. [2]
The paper used the term “exercise mimetics” to describe compounds that reproduce selected exercise-associated responses. That term should be interpreted narrowly. The experiment did not demonstrate that AICAR reproduces every adaptation to exercise or provides equivalent benefits in people. A treadmill result in mice cannot establish a human training, weight-management, or performance outcome.
DO ALL AICAR EFFECTS DEPEND ON AMPK?
No. A 2018 study examined cells genetically lacking both AMPK catalytic alpha subunits. AICAR still changed signaling involving LATS1 and LATS2, proteins associated with the Hippo pathway, which helps regulate cell growth. [3]
This finding matters when designing and interpreting experiments. Observing a response after adding AICAR does not, by itself, prove that AMPK caused it. Stronger mechanistic evidence requires additional controls, such as comparing cells with and without the relevant pathway or using another method to investigate the same target.
WHAT HAVE HUMAN METABOLIC STUDIES SHOWN?
A 2007 study involving 29 healthy men examined short-term muscle glucose handling. The researchers reported increased uptake of a glucose tracer in muscle after AICAR exposure, with a comparatively small change in whole-body glucose disposal. They did not detect increased muscle AMPK activity at the measured time points. [4]
These results describe an acute physiological experiment. They do not establish sustained improvements in metabolic health, weight loss, or exercise performance. They also illustrate why findings from rodent models cannot simply be assumed to occur through the same mechanism in humans.
WHAT DID THE LARGE CARDIAC-SURGERY TRIAL FIND?
The RED-CABG trial evaluated acadesine in patients undergoing coronary artery bypass surgery. This randomized, double-blind trial was stopped after 3,080 participants had been randomized because an interim analysis indicated a low likelihood of demonstrating the intended benefit. [5]
Acadesine did not reduce the combined primary outcome of death, nonfatal stroke, or severe left-ventricular dysfunction requiring mechanical support. The outcome occurred in approximately 5% of participants in both groups. [5]
That result applies to the population and surgical setting studied. It does not resolve every question about AICAR biology, but it is an important counterpoint to claims based only on favorable laboratory findings.
WHAT REMAINS UNCERTAIN?
The studies reviewed here answer different questions: how cells respond, how mice perform in a defined test, how human muscle handles glucose over a short period, and whether a clinical intervention improves surgical outcomes. These findings should not be combined into a general claim that AICAR improves health or substitutes for exercise.
For laboratory research, careful identification of the material, appropriate experimental controls, and measurement of more than one outcome are important. Published findings also do not establish the identity, purity, stability, or performance of a separately supplied product. Those properties require documentation and testing specific to the material being used.
REFERENCES
[1] Corton JM, Gillespie JG, Hawley SA, Hardie DG. 5-aminoimidazole-4-carboxamide ribonucleoside. A specific method for activating AMP-activated protein kinase in intact cells? European Journal of Biochemistry. 1995;229(2):558–565.
https://pubmed.ncbi.nlm.nih.gov/7744080/
[2] Narkar VA, Downes M, Yu RT, et al. AMPK and PPARdelta agonists are exercise mimetics. Cell. 2008;134(3):405–415.
https://doi.org/10.1016/j.cell.2008.06.051
[3] Philippe C, Pinson B, Dompierre J, et al. AICAR Antiproliferative Properties Involve the AMPK-Independent Activation of the Tumor Suppressors LATS 1 and 2. Neoplasia. 2018;20(6):555–562.
https://doi.org/10.1016/j.neo.2018.03.006
[4] Cuthbertson DJ, Babraj JA, Mustard KJW, et al. 5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside acutely stimulates skeletal muscle 2-deoxyglucose uptake in healthy men. Diabetes. 2007;56(8):2078–2084.
https://doi.org/10.2337/db06-1716
[5] Newman MF, Ferguson TB, White JA, et al. Effect of adenosine-regulating agent acadesine on morbidity and mortality associated with coronary artery bypass grafting: the RED-CABG randomized controlled trial. JAMA. 2012;308(2):157–164.