AICAR

A cell-energy-sensor (AMPK) activator with decades of legitimate lab use and a doping history — part of the same 2008-era "exercise mimetic" excitement as Cardarine. ATX-304 (O-304) is a distinct, clinical-stage AMPK activator that circulates under the same umbrella; it is not the same molecule.

A naming point that matters: the compound given in human studies is acadesine (AICA-riboside), which cells take up and phosphorylate into ZMP, the actual AMPK-activating molecule. Products and papers use the names interchangeably and they are not the same chemical species. What ZMP does is activate AMPK, the enzyme that acts as a cell's low-energy alarm — when it fires, cells switch from building to burning, increasing glucose uptake and fat oxidation. Because exercise activates AMPK too, AICAR became the original "exercise mimetic" after mice given it ran substantially further without training. Two facts constrain everything else about it: it is not orally active in any meaningful way, and the effects that made it famous came from injection over weeks.

Real human infusion studies exist (cardiology contexts, decades old) plus the famous mouse endurance work. For fat-loss use: nothing.

• NONE SHOWN for endurance or body composition in healthy people. Its human programme was substantial and cardiac: the RED-CABG trial randomised 3,080 patients undergoing bypass surgery, with death, non-fatal stroke or mechanical circulatory support at day 28 as its primary endpoint. It was stopped for futility at 5.1% versus 5.0%. That is a large, null, phase-3 human dataset — it does not support performance use, but it is not a thin evidence base.
• The famous result is the untrained-mouse endurance study. Attempts to reproduce anything comparable in humans have not established a performance benefit.
• Oral bioavailability was measured under 5% in one human study of a solution formulation. The controlled human evidence used a different route entirely and was null on its endpoint, so no self-administered product is supported by it; low exposure is also not proof of no exposure or no risk, particularly when product contents are unverified.
• It is prohibited in sport and has featured in doping allegations and investigations. Be careful with the cycling story that circulates: a 2025 review reported no positive AICAR test, and the well-documented 2013 cycling positives concerned a different compound entirely.
• Cost is its own quiet fact: producing it at the amounts animal studies used is expensive enough that cheap oral products invite obvious questions about what is actually in them.

Effectively not orally active — human work used intravenous administration, with a short half-life. This single fact separates the evidence from the product: nothing sold as an oral capsule delivers what the studies delivered. Research-chemical supply with unverified identity and purity.

AICAR is a purine pathway intermediate; systemic exposure has documented uric-acid and metabolic effects in the infusion literature. Long-term activation of a master energy switch is uncharacterized in humans. WADA-prohibited (and actually detected in cycling). ATX-304's early-trial data does not transfer to any product sold outside its trials.

• Anyone considering any self-administered product, none of which is supported by the controlled human evidence
• Anyone with gout or chronic kidney disease, both of which the large human trial excluded
• Anyone in tested sport, where it is prohibited
• Anyone pregnant or breastfeeding

• Interactions remain uncharacterised. More informative than mechanistic speculation: the large cardiac surgery trial EXCLUDED people with gout or chronic kidney disease, and restricted caffeine, adenosine, dipyridamole and allopurinol. Exclusions are not contraindications, but they reflect what the developers were actually cautious about.
• Any tested sport, where it is prohibited.

• There is nothing useful to monitor for a compound with no established human performance effect and no oral delivery.
• For anyone who has taken it by any route: AMPK activation affects glucose handling, so blood-sugar effects are mechanistically plausible and unstudied at these exposures.

No withdrawal syndrome has been described. For oral products the measured bioavailability under 5% means exposure was likely minimal, though unverified product contents make that an assumption rather than a reassurance.

US: not FDA-approved for human use; WADA-prohibited.

Papers about this compound, not proof of the claims above. A title says what was studied, which is sometimes a negative result or a different question entirely.

• AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic Review
  Cells, 2021
• Liposome-encapsulated AICAR hydrogel regulates macrophage metabolic reprogramming via SIK1 activation to alleviate osteoarthritis
  J Nanobiotechnology, 2025

• AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic ReviewCells · 2021
• Liposome-encapsulated AICAR hydrogel regulates macrophage metabolic reprogramming via SIK1 activation to alleviate osteoarthritisJ Nanobiotechnology · 2025
• Administration of AICAR, an AMPK Activator, Prevents and Reverses Diabetic Polyneuropathy (DPN) by Regulating MitophagyInt J Mol Sci · 2024
• AICAR confers prophylactic cardioprotection in doxorubicin-induced heart failure in ratsJ Mol Cell Cardiol · 2024
• AICAr Inhibition of cardiomyocyte autophagy promotes p62-dependent NRF2 expression and protection against doxorubicin toxicityCell Mol Life Sci · 2025
• AICAR attenuates postoperative abdominal adhesion formation by inhibiting oxidative stress and promoting mesothelial cell repairPLoS One · 2022
• AICAR stimulates mitochondrial biogenesis and BCAA catabolic enzyme expression in C2C12 myotubesBiochimie · 2022
• Quantification of AICAR and study of metabolic markers after administrationRSC Adv · 2024
• AICAR decreases acute lung injury by phosphorylating AMPK and upregulating heme oxygenase-1Eur Respir J · 2021
• An intrinsic purine metabolite AICAR blocks lung tumour growth by targeting oncoprotein mucin 1Br J Cancer · 2023
• AMPK activation by AICAR reduces diet induced fatty liver in C57BL/6 miceTissue Cell · 2023
• AICAR, an AMPK activator, protects against cisplatin-induced acute kidney injury through the JAK/STAT/SOCS pathwayBiochem Biophys Res Commun · 2019