AICAR Peptide: What the “Exercise Pill” Actually Does in Humans

AICAR made sedentary mice run 44% farther. In healthy men, it didn’t measurably switch on the muscle enzyme it’s famous for.

This page covers the mouse study, the human studies of AICAR and of the same molecule as the drug acadesine, and why Cardarine isn’t the alternative.

Quick takeaways

Question	What the evidence shows
Is AICAR a peptide?	No. It’s a nucleoside, and the same molecule is the drug acadesine (2).
What did the mouse study show?	Four weeks of daily AICAR injections raised running distance 44%, and running time about 23%, in sedentary mice (1).
Has it been tested in people for exercise?	No. Human studies used IV or intra-arterial infusions to study metabolism, blood flow and heart surgery (3, 6, 7, 8).
Did it switch on muscle AMPK in people?	Not measurably in healthy men at 20 minutes or 3 hours (3).
Did acadesine work in a large human trial?	No. RED-CABG (3,080 patients) found 5.0% vs 5.1% events and was stopped for futility (6).
Is it banned in sport?	Yes. WADA lists AICAR under S4 as an AMPK activator (13).
Where are the doses?	No human dose for exercise exists, so this page lists none.

What AICAR is

AICAR isn’t a peptide. It’s a nucleoside, and the body makes it naturally. As a drug it’s called acadesine (2). In lab experiments, red blood cells took it up through a nucleoside transporter and converted it to AICA-ribotide (8).

It’s best known as an activator of AMPK, an enzyme that helps cells manage energy (1, 4).

The mouse study

In 2008, Narkar and colleagues at the Salk Institute tested drugs on mouse endurance. A PPARδ agonist combined with exercise training raised running endurance and oxidative muscle fibers. Then they tried AICAR alone. In sedentary mice, four weeks of treatment switched on metabolic genes and raised running distance 44% and running time about 23% (1). The paper calls AICAR an orally active AMPK agonist, but the mice in the endurance test were injected with it daily (1).

Later work is more mixed. In aged mice, AICAR partly mimicked exercise’s effects on memory. But exercise improved mitochondrial respiratory function in the hippocampus, and AICAR didn’t (5). A 2021 systematic review found that many effects long attributed to AICAR’s AMPK activation are AMPK-independent (4).

What happened in people

Nobody has tested AICAR for endurance in people. The human studies used infusions to study metabolism.

In 29 healthy men, IV AICAR raised muscle glucose uptake 2.1-fold over 3 hours, and exercise raised it 4.7-fold. Muscle AMPK activity and phosphorylation didn’t change with AICAR, but phosphorylation rose with exercise. Whole-body glucose disposal rose 7% (3).

In 10 men with type 2 diabetes, IV AICAR lowered liver glucose output and blood fatty acids (7). In 24 healthy people, AICAR infused into a forearm artery widened blood vessels through nitric oxide, with no change in forearm glucose uptake (8).

Acadesine in large trials

The same molecule, as the drug acadesine, was tested in 3,080 heart-surgery patients in the RED-CABG trial. An earlier meta-analysis had linked acadesine to fewer early cardiac events. RED-CABG found no benefit. The primary outcome occurred in 5.0% on placebo and 5.1% on acadesine, and the trial was stopped for futility (6).

At high IV doses in 24 patients with chronic lymphocytic leukemia, acadesine commonly raised uric acid. It also caused transient anemia or low platelets, renal impairment and infusion-related low blood pressure (9).

Those were hospital infusions in sick patients. They don’t tell you what AICAR does in a healthy athlete, and no study has measured that.

Why Cardarine isn’t the alternative

Some AICAR guides recommend Cardarine (GW501516) instead. Don’t. GlaxoSmithKline stopped developing it in 2006 after a variety of cancers turned up in routine long-term animal studies. A 2013 notice from GSK and Health Canada advised Canadians not to use it under any circumstances, and says its long-term effects in humans are unknown (12). WADA lists GW1516 under S4 (13).

Legal and anti-doping status

AICAR isn’t an FDA-approved drug. WADA lists it under S4 as an AMPK activator (13).

The body makes AICAR, so labs use carbon-isotope-ratio testing to tell it from a dose. In one study, a single oral dose was detectable for more than 40 hours (10). A 2024 study of two men given a low dose found an exogenous signature within 16 hours, which suggests the window grows with the dose (11).

If you’re still comparing options

AICAR is sold alongside peptides, but it’s a nucleoside. A certificate of analysis shows what one lot contained. See how to verify a peptide COA, and compare sellers in the best peptide vendors guide. For a mitochondrial peptide with its own mouse data, see our peptides for energy guide.

Frequently Asked Questions

Is AICAR a peptide?

No. It’s a nucleoside. Vendors sell it alongside peptides, and as a drug it’s called acadesine (2).

Does AICAR work as an exercise pill in humans?

That hasn’t been shown. In sedentary mice, four weeks raised running distance 44% (1). In healthy men, IV AICAR raised muscle glucose uptake but didn’t measurably activate muscle AMPK (3). No study has tested it for endurance in people.

Has AICAR been tested in people?

Yes, as IV or intra-arterial infusions for metabolism and blood flow (3, 7, 8), and as acadesine in heart surgery and leukemia (6, 9).

What are the side effects?

No trial has studied AICAR for exercise. At high IV doses in leukemia patients, acadesine commonly raised uric acid and caused transient anemia or low platelets, renal impairment and infusion-related low blood pressure (9).

Is AICAR safe?

Nobody knows. The human data are short infusions in hospital settings, and the large trial of acadesine found no benefit (6).

Is AICAR banned in sport?

Yes. WADA lists it under S4 as an AMPK activator (13). A single oral dose was detectable for more than 40 hours in one study (10).

Is AICAR better than Cardarine?

Neither is proven. Cardarine’s development was stopped in 2006 after cancers in animal studies, and Health Canada advises against using it (12).

Can AICAR replace exercise?

No study shows that. In aged mice, exercise improved mitochondrial respiratory function in the hippocampus and AICAR didn’t (5).