AICAR (chemical name: 5-Aminoimidazole-4-carboxamide ribonucleotide) is a peptide, which is an intermediate within the generation of inosine monophosphate and directly related to metabolic regulation. The most important mechanism that AICAR is known for is its ability to block enzymes both in intracellular and extracellular levels, which, in turn, allows for an accelerated stimulation of glucose uptake and increase protein kinases in skeletal muscle tissue. These two functions allow for more energy conversion, which helps burn fat and also sustain output in activity. This is what scientists and athletes/bodybuilders are interested in, but there are some amazing side effects.
Interestingly, AICAR has been shown to protect against ischemic injury. This type of injury is directly related to the restriction of blood to tissues, which can cause insufficient amounts of oxygen and glucose needed to keep the tissue alive. This can lead to thrombosis, embolisms, and vasoconstriction. AICAR can be used as a stabilizing peptide for ischemic episodes, and it can allow for proper blood flow to the myocardium (heart). This function is very interesting, as AICAR could be fundamentally used to treat the heart muscle in the aftermath of a heart attack. This might reduce the possibility for ischemic injuries. Abnormal growths of heart tissues and heart valve function have also been altered in animal studies that used the peptide AICAR, which is a downside.
Fig 1. AICAR chemical structure
Table of Contents
AICAR uses metabolic pathways to block certain enzymes, which allows for AMP-activated protein kinase. This can be explained to the layperson like this: once you take a substantial amount of AICAR, it tricks your body at a cellular level in to thinking that exercise has just been preformed. Since the body thinks it has just done a considerable amount of exercise, the energy cycle at the cellular level starts converting fuel sources, like fatty acids, to output the energy that was thought to have been spent during exercise. This can have a direct effect on the level of endurance activity and the sustainability of that activity. Insulin sensitivity is also noted to be one action that AICAR produces, as the body will think it just went through a series of exercises. Interestingly, in animal studies with obese mice, AICAR showed all of the peptides benefits for obese diet induced mice, yet the healthy lean mice did not reap any of the benefits of insulin sensitivity or increase in glucose uptake. That being said, the application in bodybuilding does not seem very suitable, as these mechanisms are targeted for the out-of-shape and over-weight, so if you are not a top level endurance athlete I just do not see the reason for using AICAR. A much better option would be Cardarine (GW-50156), as this compound is readily activated by exercise, so the need to work out or cardio would be an incentive.
Dosage and Usage
Here is where AICAR becomes a pipe dream for anyone who is not a top level endurance athlete or bodybuilder. The dosages recommended to achieve the benefits from this peptide are insanely high. AICAR must be dosed at around 500mgs per kilogram (kg) of body weight. A gram of real pure AICAR can cost $100 USD or more, so single dosages for humans could be well in to the several hundreds of dollars! Some say that this can be circumvented by stacking it with Cardarine (GW), but you still need to spend a lot of money for perhaps little to no result if you are not dosing high enough dosages.
Yes, the peptide AICAR has amazing properties, some which even show the slowing of growth in cancer cells, but for the average athlete this has no basis in a day to day regiment. On the other hand, Cardarine (GW) has been shown to provide users with more than enough results as an Activated Receptor d agonists (PPARd) and it's cost-effective for everyone.
The most concerning side effects from AICAR are the direct effects it has on your heart. It can cause enlarged growth in cardiac tissue, and it can effect blood flow. In turn, this could affect the flow of blood to a person’s brain. In addition, it has been noted that defects of heart valves may also be caused by the peptide AICAR. The heart is the most important muscle in the entire body, and the last thing anyone wants to do is treat it badly. Anecdotally, some logs indicated extreme loose bowls, dry mouth, and lack of hunger.
Summary of AICAR side effects
- Possible enlarged growth of heart
- Possible defects to the heart valve
- Problems with blood flow
- Problems with blood and nutrient transfer to the brain
- Problems with bowls
For the cost and the potential side effects, the peptide AICAR has no real use in the sports or bodybuilding world. It is touted as exercise in a bottle, but most athletes don’t want to sit around and do nothing, they actually enjoy being active and staying fit. This is why Cardarine is by far the more superior PPARd, as it is activated by exercise and has many of the same benefits that AICAR does without the extremely nasty side effects. Unless you are a professional endurance athlete with extra money to spend and need the very small edge over competition, there is very little reason to use AICAR.
Obesity in mice - http://www.ncbi.nlm.nih.gov/pubmed/20844264
Regarding ischemia - http://www.ncbi.nlm.nih.gov/pubmed/22324445
Cancer cell growth inhibited by AICAR - http://www.sciencedirect.com/science/article/pii/S0005272810007899