Is Cardarine Safe? Does It Really Cause Cancer?

Everyone is getting into fitness. For the last decade or so, this has been an industry that has only been growing exponentially. And with that comes the craze for bodybuilding. If you are anywhere near these conversations, you have probably heard of those who take anabolic steroids.

You might have also heard of athletes using SARMs and peptides lately, with many referring them to “safer” alternatives to anabolic steroids. But how safe are they really?

In this article, we’re taking a look at the safety profile of a single drug: Cardarine. Specifically, we’re going to try to answer the question of whether Cardarine is safe or not. Does it really cause cancer? You’ll want to read this if you plan on using it in your next cycle.

What do studies say about the safety of using Cardarine?

Safety Profile

Cardarine, also known as GW501516 or Endurobol, entered the market in the 1990s and was made to help with improvement in physical performance. Some researchers found that it can cause cancer and the studies were halted. But there are others who state that it needs to be debated because of the way in which the dosage was issued. So we looked at a variety of studies to determine if cardarine really causes cancer.

Cardarine was developed to help treat obesity, diabetes and other heart issues because it had the potential to reverse metabolic abnormalities. The phase I trial of the animal testing began in 2000. 

Several clinical trials were conducted in the early days and here are the results. When tested on mice, some studies showed that cardarine increased the running performance in both trained and untrained mice.

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This improvement in running endurance was seen even in untrained mice after just one week. This was the result of an increase in fatty acid utilization after cardarine was given to them. The blood glucose levels of mice that were treated with GW501516 was also higher after exercise. The improvement was significant in trained mice and unexpectedly higher in untrained mice.

The running performance was measured by wheel running (as opposed to treadmill running) since that was considered more natural and a better way of measuring their abilities. Some studies have also shown a difference in response to training and aerobic capacity in inbred and hybrid rodents.

Studies were also undertaken to see if cardarine had any therapeutic effects in insulin-resistant and chronic high fat feeding rats and mice. The results showed that insulin resistance in the muscles worsened in rats but improved in mice.

So they concluded that even though this might be of some benefit to human beings, the species for a preclinical study must be carefully chosen, especially if it is to be used to treat metabolic conditions. 

Cardarine discontinued over cancer scares: fact or fiction?


While that sounded like good news, it was found that when cardarine was given to rats and mice for two years, they became prone to developing the risk of a range of cancers.

This led to the official testing being abandoned before it even proceeded to human trials. It became something that was procured in the sporting circles for enhanced performance. Various anti-doping agencies took note of that and put it on the prohibited list.

The controversy started with arguments that limited studies on human beings showed that there were no known side effects. Some argue that this is because of the short duration of the studies and the use of small doses. But it still begs the question, will this change if prolonged studies are undertaken.

How to use Cardarine safely without getting side effects?

Safe usage

It has since been established that a lot of the harmful outcomes were because the rodents were given an excessive dosage of cardarine for a really long time. And also that there is a need for further studies to determine if cardarine can be of use to humans even if for a limited period of time and in smaller doses.

Now, this is a drug that while banned and condemned by many, is still available on the black market. It is regularly used (and abused) by gyms and other fitness organizations. So if you happen to get your hands on it, how do you make sure you are safe?

Know that it must be taken in normal quantities, you must not take it for too long (or maintain a regular cycle length) and you must not mix it up with other drugs. This is important to note because those who use cardarine are also known to add other products like ostarine to help them build muscle mass. This should be avoided.

A normal dosage of cardarine is up to 30 mg a day. But, it is most effective when you take 10-20 mg every day. You should take this one or two hours before your workout session and follow this cycle for four to eight weeks at a time. This way, you can avoid the side effects and improve your stamina. If you want to check out the different kinds of SARMs for the same reason, take a look here.

Final verdict: is Cardarine safe to use or not?

Final Verdict

The unregulated use of cardarine has a series of terrible and long-term side effects. This is primarily the reason for anti-doping agencies and the FDA to have declared it illegal. But since it is available as a research substance, cardarine in combination with some other drugs has become a popular choice for those who want to build their body and improve their stamina.

The results of its toxicity are readily available for those who want to learn about it. The World Anti-Doping Agency or WADA has put in some effort to warn users of its health risks.

They don’t say, live life in moderation for nothing. While there seem to be a few benefits of using this, you must be aware of the potential risks when using cardarine. You can reap a few benefits of this product when used in limited doses, for a limited period of time and without mixing it up with other unhealthy products that are often recommended as a gimmick.

And most importantly, educate yourself on why certain products are given clearance for testing on humans and some others aren’t. And check with yourself, and most importantly a qualified doctor, on whether that works for you.

Chris Jackson
Chris Jackson

Chris Jackson, co-founder of, is a renowned fitness blogger, physique model, and evolutionary bioscience researcher specializing in SARMs (Selective Androgen Receptor Modulators). His extensive work, characterized by cutting-edge research and practical training advice, has made a leading source for accurate, credible information on performance enhancers. With a dedication to improving the understanding and application of SARMs in optimizing human performance, his contributions have not only expanded public awareness but also shaped the conversation around these substances. Chris's pursuit of knowledge and commitment to sharing it continue to inspire many in their fitness journeys.

  1. The author needs to read the above comment. This article was a mess, claims made that weren’t even relevant, let alone had no substantiation in the very same article. Unless they were trying to fill this page with keywords the article appears amateurish.

  2. First, the Final Verdict has nothing to do with all of the previous discussion. “A series of terrible and long-term side effects”? Really? Where was that discussed? When you said ONE experiment with uber high dosages on mice for years non-stop resulted in cancer? Then you say to avoid mixing with Ostarine or other drugs… But you have 20 other articles in this same site suggesting to stack it with Ostarine. Are you kidding me?

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