Aicar

Product Description

AICAR (also known as Acadesine or 5-aminoimidazole-4-carboxamide ribonucleotide) is an experimental synthetic nucleotide analog. It is most commonly sold as a research chemical and is widely used in scientific studies investigating cellular energy metabolism. It is not a steroid, not a hormone, and not an approved drug for human use.

Chemical identity and structure

• IUPAC name: 5-amino-1-β-D-ribofuranosylimidazole-4-carboxamide
• Molecular formula: C₉H₁₄N₄O₅
• It is structurally an intermediate in purine biosynthesis. In its phosphorylated form, AICAR monophosphate (ZMP), it mimics the effects of AMP (adenosine monophosphate).

Primary mechanism of action

AICAR’s biological activity comes primarily from its conversion inside cells to ZMP. ZMP is a potent activator of AMP-activated protein kinase (AMPK) — an enzyme that acts as a central cellular energy sensor.

When AMPK is activated, it shifts cells toward catabolic (energy-producing) processes and away from anabolic (energy-consuming) processes. Specifically, AMPK activation by AICAR leads to:

• Increased glucose uptake – through enhanced GLUT4 translocation to cell membranes.
• Increased fatty acid oxidation – by phosphorylating and inactivating acetyl-CoA carboxylase (ACC).
• Mitochondrial biogenesis – through upregulation of PGC-1α, promoting the creation of new mitochondria.
• Inhibition of protein synthesis – via suppression of the mTOR pathway (at high doses).
• Improved insulin sensitivity – in insulin-resistant tissues.

Because of this, AICAR has been described as an “exercise mimetic” — it triggers metabolic adaptations in resting muscle that partially resemble the effects of prolonged endurance exercise.

Historical and research background

• AICAR was originally developed decades ago as an anti-ischemic agent (used experimentally to protect heart tissue during coronary artery bypass surgery). It underwent clinical trials for this purpose but was not approved due to lack of clear efficacy and safety concerns (e.g., potential cardiac rhythm effects).
• Since the 2000s, it has become one of the most important research tools in metabolic and exercise physiology. It has been used extensively in rodent studies to explore the role of AMPK in muscle metabolism, obesity, and type 2 diabetes.
• It is also used in cell culture studies to induce AMPK activation and study downstream signaling pathways.

Study findings (preclinical)

In animal models, AICAR administration (typically intraperitoneal or subcutaneous injections, often 0.5–2 mg/g body weight per day, though protocols vary widely) has been shown to:

• Increase running endurance in sedentary mice by roughly 40% after 4 weeks of treatment.
• Improve glucose tolerance and reduce fat accumulation in diet-induced obese mice.
• Increase mitochondrial density in skeletal muscle.

However, these effects were observed in sedentary animals under tightly controlled laboratory conditions. Translating these findings to humans is not straightforward, and human studies have shown inconsistent effects on performance and metabolism.

Athletic use and “ethical” controversy

AICAR gained notoriety in 2013 when a professional cyclist (and later others) were linked to its use as a performance-enhancing drug. It is believed that some athletes use AICAR to:

• Improve endurance capacity.
• Enhance fat utilization during exercise.
• Mimic some of the benefits of training without actual training.

Important points regarding athletic use:

• The World Anti-Doping Agency (WADA) has banned AICAR (and its analogs) as a metabolic modulator (Class S4.5). It is prohibited at all times, both in and out of competition.
• There is no reliable evidence that AICAR enhances human athletic performance to a meaningful degree, and it carries significant health risks.
• Reported non-medical use usually involves injectable formulations (subcutaneous or intramuscular) of the raw peptide/nucleoside powder, often purchased from unregulated black-market suppliers.

Side effects and safety risks

AICAR is not a benign supplement. Documented and theoretical adverse effects include:

• Cardiovascular effects: In clinical cardiac trials, acadesine was associated with a small but concerning increase in incidence of cardiac arrhythmia (atrial fibrillation) in some patient groups. This is a significant concern for healthy athletes using the drug.
• Hypotension: It can cause a drop in blood pressure.
• Lactic acidosis: Because it promotes glycolysis and fat oxidation, high doses may push metabolism towards lactic acid production.
• Hepatotoxicity: Elevations in liver enzymes have been observed in animal studies.
• Gastrointestinal distress: Nausea, diarrhea, and cramping at higher doses.
• Unknown long-term consequences: Chronic AMPK activation is implicated in cell growth regulation and apoptosis (programmed cell death). Excessive or prolonged AMPK stimulation could theoretically influence tumor suppression or, conversely, promote metabolic dysfunction (e.g., “AMPK paradox”).

Legal and regulatory status

• Not a controlled substance (as of current schedules) in most countries. It is not listed alongside anabolic steroids.
• However, AICAR is not an approved drug in any country for human use. In the United States, it is not FDA-approved for any indication. Selling it for human consumption is illegal under food and drug laws, even if not scheduled as a narcotic.
• It is sold legally in many jurisdictions as a research chemical for laboratory use only. Reputable suppliers restrict sales to accredited institutions, but underground sources often circumvent this.
• In sport, it is a prohibited substance under the WADA code. Athletes testing positive face sanctions.

Summary / Important caveats

• AICAR is a potent experimental AMPK activator used primarily in scientific research.
• It has shown promise as a metabolic modulator in animal models but has never been proven safe or effective for human use.
• Its use as a purported performance enhancer is unproven and potentially dangerous, particularly due to cardiac risks.
• It is not an anabolic steroid, not a hormone, and not a “natural” supplement. It is a synthetic chemical compound with serious pharmacological activity.
• Any purported “performance-enhancing” or “health-promoting” use outside of a properly regulated clinical trial is both unsafe and often illegal.