Last Updated: August 21, 2025
Cardarine, also known by its chemical name GW-501516 or the brand name Endurobol, has become a topic of intense interest in the fitness and athletic communities. This compound, originally developed for its potential therapeutic benefits, has found a new life among bodybuilders and athletes seeking to enhance their performance and achieve their fitness goals more efficiently.
The allure of Cardarine lies in its unique mechanism of action, which promises to deliver significant improvements in endurance and fat loss without the traditional side effects associated with anabolic steroids. However, like any substance that manipulates the body’s natural processes, Cardarine comes with its own set of risks and potential side effects.
What is Cardarine?
Cardarine is a research chemical that was developed for its potential to increase metabolism and fat loss, and promote muscle growth. Also known as GW501516 and Endurobol, this compound may boost exercise performance and workout capacity, according to research.
Cardarine is popular in the bodybuilding community due to its performance-enhancing abilities. It has also been used by elite athletes to enable them to elevate their performance levels. As a result, Cardarine has been banned by most sports-governing bodies.
Cardarine is a peroxisome proliferator-activated receptor (PPAR) agonist. PPARs are a group of nuclear receptors that play a crucial role in regulating various biological processes, including lipid metabolism, glucose homeostasis, and cell proliferation. [1]
By activating PPARδ, Cardarine influences how the body uses fat for energy, leading to enhanced endurance and fat loss. [2][4]
Cardarine was initially developed by GlaxoSmithKline and Ligand Pharmaceuticals in the early 1990s as a potential therapeutic agent for treating metabolic disorders and cardiovascular diseases. The compound showed promising results in early clinical trials, particularly in improving lipid profiles and reducing inflammation. However, its development was halted due to concerns over potential carcinogenic effects observed in animal studies. [3][4]
Despite its intended therapeutic use, Cardarine has found a new life in the fitness and athletic communities. Bodybuilders and athletes use it to enhance endurance, increase fat loss, and improve overall performance. Its popularity stems from its ability to mimic the effects of exercise by forcing skeletal muscle to use fat as an energy source, thereby increasing endurance and reducing body fat.
Is Cardarine SARM or a Steroid?
Cardarine does not function as a steroid or a SARM (selective androgen receptor modulator). It is technically a PPAR antagonist.
SARMs stimulate the androgen receptors in muscle and bone tissues, which causes an increase in muscle mass.[5] Conversely, Cardarine is a PPAR-delta activator and doesn’t directly interact with androgen receptors.
How Does Cardarine Work?
Cardarine works by binding to PPAR-delta receptors in the body, which are found in muscle and fat tissues. PPAR-delta is thought to be linked with muscle growth, improving cardiovascular health, increasing metabolism, and decreasing inflammation.[1][4]
This activation leads to an increase in the expression of genes involved in fatty acid oxidation and energy expenditure. As a result, the body shifts towards using fat as a primary energy source, reducing reliance on carbohydrates and enhancing endurance.
Additionally, Cardarine has been shown to increase the production of certain enzymes that help in the breakdown of fatty acids, further contributing to its fat-loss effects.
Benefits of Cardarine
Cardarine, a PPARδ agonist, offers a range of benefits that make it appealing to athletes and individuals seeking to enhance their physical performance and body composition. These benefits are rooted in its ability to manipulate metabolic pathways, leading to improved endurance, fat loss, and muscle growth.
Weight Loss and Fat Loss
Cardarine is known to accelerate fat loss by increasing fatty acid oxidation and enhancing glucose uptake in skeletal muscle tissue[6][9]. This results in the body using fat as a primary energy source, leading to rapid fat loss and a leaner appearance. Studies have shown that Cardarine can significantly reduce body fat by promoting lipolysis and increasing the metabolism of fatty acids[3][10].
Improved Endurance
One of the most notable benefits of Cardarine is its ability to enhance endurance. By activating PPARδ receptors, Cardarine increases the expression of genes involved in fatty acid oxidation and energy expenditure, allowing for longer and more intense training sessions[6][9]. This effect is particularly beneficial for athletes who require sustained energy levels during prolonged periods of exercise.
Muscle Growth and Recovery
Cardarine also aids in muscle building by facilitating the development of existing muscle cells and the formation of new ones[6][7]. This is achieved through the upregulation of PPAR genes in slow-twitch muscle fibers, which enhances oxygen utilization and allows for quicker recuperation and the ability to exercise more frequently.
Blood Lipid Levels
Cardarine has been shown to improve blood lipid levels by increasing HDL cholesterol and reducing triglycerides[4]. This effect is beneficial for cardiovascular health and can help in managing conditions such as hyperlipidemia and type 2 diabetes mellitus.
Other Potential Benefits
Additional benefits of Cardarine include its potential anti-diabetic properties, protection against kidney and liver diseases, and neuroprotective effects[7][8]. These benefits are attributed to its ability to regulate metabolism, reduce inflammation, and improve insulin sensitivity.
Overall, Cardarine offers a comprehensive set of benefits that can enhance physical performance, improve body composition, and support overall health. However, it is crucial to consider the potential risks and side effects associated with its use, particularly the risk of cancer from long-term use[6][9].
Risks and Side Effects
Cardarine, despite its potential benefits, comes with significant risks and side effects that cannot be overlooked. The most concerning aspect of Cardarine use is its potential to cause cancer, as indicated by animal studies.
Cancer Risks
GW501516 was found to accelerate the development of cancerous tumors in rats, according to a 2007 study by GSK (GlaxoSmithKline). For this reason, further development and research into the drug was halted [11][12].
This risk is particularly alarming because it suggests that long-term use of Cardarine could lead to an increased risk of developing cancer in humans, although this has not been directly proven due to the lack of extensive human trials. However, there is a great deal of controversy surrounding this research because the study used large doses of Cardarine for extremely long cycles.
In this animal study, the doses of 3-40 mg were administered to rats . However, even just 3 mg given to a rodent is the human equivalent of over 40 mg per day for an individual weighing 190lbs – 2-4 times larger than the typical dose.
But perhaps even more significant is the fact that the rats were given Cardarine for a whopping 104 weeks – more than two years! This is 13 times greater than a typical 8-week cycle. From this data, we can reasonably conclude that Cardarine may cause cancer if taken in large doses of over 40 mg per day, and over a very long period of time (2 years+).
However, many people maintain that Cardarine appears to be safe when used correctly, following a normal dosage and cycle length. Of date, GW501516 has not been connected to any known instances of cancer in humans. This is probably due to the fact that Cardarine is not typically taken in large doses over 104-week cycles .
In fact, there have been studies since that contradict the research showing cancer development, and one study has actually shown that GW-50156 has anti-cancer properties if used correctly.[13]
Basically, this study showed that Cardarine doesn’t lead to the development of cancerous tumors, even at extreme doses over short periods of time. Additionally, the compound actually demonstrated some anti-cancer properties during the trial.
The doses given were equivalent to 154mg per day for an individual weighing 200 lbs. Even at these mega-dosages there were no signs of cancer development when used in short 7-day cycles
Liver Damage
Cardarine has been shown to cause liver damage in some studies. It may lead to liver cell death and fibrosis, especially in individuals with pre-existing liver conditions[11]. Symptoms such as jaundice, dark urine, abdominal pain, or unexplained fatigue should be monitored closely.
Neurotoxicity
Research suggests that Cardarine may cause damage to brain cells and impair cognitive function. Long-term use of Cardarine has been linked to neurotoxicity in mice, highlighting the potential for similar effects in humans[10][11].
Cardiovascular System Problems
Cardarine use has been associated with cardiovascular system problems, including increased risk of heart disease and cardiovascular events[11].
Muscle Cramps and Joint Pain
Muscle cramps and joint pain are also possible side effects of Cardarine use, although these are less severe compared to the other risks mentioned[10].
Other Side Effects
Other potential side effects of Cardarine include impaired bone formation, leading to decreased bone mineral density and deterioration of bone properties[10].
Given the significant risks and side effects associated with Cardarine, its use is not recommended. The lack of extensive human trials and the potential for severe health consequences make it a dangerous compound to use for performance enhancement or any other purpose.
Usage and Dosage
Despite the risks and side effects associated with Cardarine, some individuals may still choose to use it. It is crucial to understand the proper usage and dosage guidelines to minimize potential harm.
Recommended Dosage
Based on anecdotal user reports, a typical Cardarine dose is 10-20 mg per day. New users should probably start with a 10 mg daily dose or lower to assess its effects and gradually increase as needed, while closely monitoring for side effects.
Most users do not consume more than a 25 mg daily dose, as it is believed that this dose is more than sufficient to achieve excellent results. Anything higher will be counterproductive.
Cardarine has a half-life of 12-24 hours. This means that it can be taken either as a full dose once daily, or a half-dose twice daily, to maintain consistent results.
It is often taken once in the morning, and once before exercise. It takes about 20-30 minutes for the body to feel the effects of this supplement.
Cycle Guidelines
Cardarine cycles typically last 6 to 12 weeks, depending on fitness goals. It is recommended to start with a short cycle and assess tolerance and effectiveness before extending the cycle duration. Post-cycle therapy (PCT) is not necessary for Cardarine, as it does not suppress natural hormone production.
Stacking
Cardarine is often stacked with other with other SARMs, including Ostarine and RAD140. However, stacking increases the risk of side effects and interactions between compounds. It is essential to research and understand the potential risks and interactions before combining Cardarine with other substances.
Does Cardarine Require PCT?
A common question often asked about Cardarine is if post-cycle therapy is required when using it (PCT). Caradine is non-hormonal in its action and won’t cause a suppression of natural testosterone production.
Therefore, no post-cycle therapy is required for Cardarine. You definitely need a PCT with steroids, and even some SARMs, but not with Cardarine.
However, if you stack it with other compounds that suppress testosterone (Ostarine is commonly stacked with Cardarine, for example), you will need to follow-up with post-cycle therapy.
Precautions
When using Cardarine, it is crucial to take precautions to minimize potential harm. This includes:
- Monitoring for Side Effects: Regularly check for signs of liver damage, cardiovascular problems, and other side effects.
- Liver Support: Consider using liver support supplements to help mitigate potential liver damage.
- Regular Blood Work: Regular blood tests can help identify any adverse effects on liver function, lipid profiles, or other health markers.
- Avoiding Long-Term Use: Limit Cardarine use to short cycles to reduce the risk of long-term side effects, including cancer.
Legal Status and Ethical Considerations
Cardarine, also known as GW-501516, has a complex legal status and raises significant ethical considerations due to its potential health risks and abuse in sports.
WADA Prohibition
Cardarine is listed on the World Anti-Doping Agency (WADA) Prohibited List under the category S4, “Hormone and Metabolic Modulators,” due to its ability to influence performance by altering gene expression[14][15]. This classification makes it illegal for athletes to use Cardarine in competition, as it is considered a form of doping.
Regulatory Status
In Australia, Cardarine is not listed in the Therapeutic Goods (Permissible Ingredients) Determination No. 4 of 2017, and it is not an excipient or active in any medicines on the Australian Register of Therapeutic Goods (ARTG)[14]. This means that Cardarine is not approved for therapeutic use and is considered a substance of abuse with potential carcinogenic effects.
Health Risks and Ethical Concerns
The use of Cardarine poses significant health risks, including potential carcinogenic effects, liver damage, and cardiovascular problems. These risks are compounded by the lack of systematic investigation into its effects on humans and the unregulated supply of the substance on the black market[14][15].
WADA Warning
In 2013, WADA issued a rare warning to athletes about the health risks associated with Cardarine, emphasizing the potential for serious toxicities and the lack of reliable data on its safety in humans[15]. This warning underscores the ethical concerns surrounding the use of Cardarine and the need for athletes to prioritize their health and safety.
Ethical Considerations
The use of Cardarine raises ethical questions about the pursuit of performance enhancement at the expense of health and safety. Athletes who use Cardarine are not only risking their own health but also undermining the integrity of sports by engaging in doping practices.
Cardarine Alternatives
Because there is currently such limited data available concerning this research drug, we cannot recommend using Cardarine. It could potentially lead to serious side effects.
Cardarine is popular because of its benefits to fat loss, endurance and energy. However, because it has not been proven safe, you should look at other options.
We recommend the CrazyBulk Cardarine alternative called C-DINE 501516. This natural SARM alternative contains potent all-natural thermogenic fat-burning ingredients that are combined to mimic the effects of Cardarine.
It safely boosts energy, metabolism, and fat loss, and suppresses the appetite. C-DINE 501516 is a natural and safe option for taking performance to the next level.
Also check out our full reviews for CrazyBulk’s SARM Products.
Where to Buy
Cardarine is a highly sought-after product that should be purchased only from a trusted vendor. It is important to search for a reliable website that can guarantee a high-quality product using third-party lab testing.
Based on our research, we found SwissChems to be a highly reputable vendor from which to purchase Cardarine.
They offer GW501516 in bottles of 60 10 mg capsules. Click here for the official SwissChems product page.
This company is the best choice because of their superior quality control standards.
Many online vendors you find don’t have their products tested by a third party, so you can’t be sure of what you’re getting. If you are determined to buy Caradine, make sure you get a product that’s been thoroughly vetted for purity and effectiveness.
Conclusion
Although Cardarine’s potential is promising, the available research is still limited. Even so, this hasn’t prevented a number of people from researching it to improve their performance.
Although GW501516 is still available from some vendors, we cannot recommend that you buy it. That said, if you are set on obtaining it for yourself, you can still get it from the SwissChems website.
They are the best source for these types of compounds and they thoroughly test all of their products.
We believe there are better options available that don’t pose any potential health risk and are perfectly legal to buy and use. The CrazyBulk’s C-DINE 501516 can help you increase your performance, energy, and fat loss. It will also suppress your appetite.
It’s important to remember that your safety is paramount. While we’re all focused on improving performance, it must be done in a responsible manner.
Jim is the founder of Andro HQ and a self-taught supplement reviewer with over 12 years of personal testing experience. He has evaluated more than 150 bodybuilding products and specializes in identifying effective, science-backed alternatives to banned substances. His insights are grounded in real-world use, documented trials, and continuous experimentation in the gym. While not a licensed health professional, Jim aims to help readers navigate the often-confusing supplement market through honest, evidence-informed reviews. More about this author…