Why would some bodybuilders take a muscle building supplement that might shrink their testicles and cause ruptures to their Achilles tendons when there are safer alternatives out there? We take a look at research into the safety of selective androgen receptor modulators (SARMs), a controversial group of anabolic agents that has recently gained popularity among people who want to build muscle mass and grow stronger.
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What makes SARMs so special among anabolic agents?
The world “selective” in its name refers to the fact that SARMs target only your muscles and bones, whereas most other anabolic agents affect other areas of the body as well, and not always in a good way.
SARMs activate the androgen receptors in your muscles and bones. This increases the testosterone uptake there, which in turn increases muscle size and bone density.
This class of drugs was developed in the late 1990s in an attempt to replace anabolic androgenic steroids, which have various medical uses but also a wide variety of negative side effects.
SARMs are sold – mostly online – under names such as enobosarm (aka ostarine), ligandrol, vosilasarm (aka RAD-140), and S-23.
Well, this all sounds pretty positive so far! So, what’s the problem?
SARMs: The good, the bad, and the ugly
The good
The vast majority of SARMs users are young men who want to grow bigger muscles.
However, they are also popular as a muscle building supplement for women because, unlike some other anabolic agents, they do not cause a deeper voice and male-pattern hair growth.
Some competitive athletes use SARMs in the hope that it will make them stronger.
A 2022 survey among people on the social media platform Reddit who use SARMs found that more than 90% of the male respondents were satisfied with their SARMs usage and reported increased muscle mass.
The bad and the ugly
However, that same survey found that more than 50% of SARMs users reported significant side effects, including mood swings, shrinking testicles, and acne.
In 2023, a team of scientists in the USA published the results of their systematic review of the research into the safety of SARMs for recreational users. They looked at 15 case studies as well as 18 clinical trials involving more than 2,000 people.
Among the more serious negative side effects of SARMs that these studies found were:
liver damage
rhabdomyolysis (when high concentrations of toxins released from your muscles enter your blood stream, which can damage your kidneys)
a reduction in HDL cholesterol (i.e. “good” cholesterol), which can increase the risk of heart disease.
Some of the less serious side effects of SARMs were found to be:
smaller testicles
mood swings
acne
headaches
dry mouth
upper respiratory infections
constipation
indigestion
nausea.
The legal situation with SARMs
Recreational and medical use
SARMs are illegal in the USA and many other countries. This is not because the government doesn’t want you to be ripped – it’s because of the serious health risks!
The USA’s Food and Drug Administration (FDA) said in 2023 that SARMs cannot be legally marketed in that country as a dietary supplement or as a drug. So, it’s not even legal for your doctor to prescribe you a SARM.
The FDA warns that SARMs “are often sold with no warnings on the labels, potentially leading consumers to believe the products are safe”.
A 2023 study of how SARMs are being marketed on the social media platform TikTok found that:
Sellers of SARMs try to circumvent the law by claiming it is being sold as “research chemicals” and that it is “not for human consumption”, while featuring pictures of ripped people and hashtags that refer to bodybuilding. (Nudge-nudge, wink-wink!)
In the USA alone, content on TikTok with hashtags referring to SARMs had 40 million views over the course of three years, with 33 million of those views coming from 18- to 24-year-olds.
Sports performance
SARMs are banned in sport for two reasons:
It might enhance performance (although this has not been proven scientifically).
And obviously, due to the dangerous negative side effects.
The World Anti-Doping Agency has banned the use of SARMs since 2008 for all levels of sport – from professional to recreational.
The US Anti-Doping Agency reported in 2020 that more than 50 USA athletes have been sanctioned for the use of SARMs since 2010, and that there have been more than 230 positive tests worldwide since 2012.
Our recommendation
It’s obvious from the above: Don’t use it. There are safer supplements, such as creatine, which have proven benefits and don’t pose serious health risks.
If you are already using it, we suggest that you stop, and seek medical help if necessary.
How we can help
Need more help with an injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.
We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine or at least 10 years' experience in the field. But at Sports Injury Physio we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.
About the Author
Maryke Louw is a chartered physiotherapist with more than 20 years' experience and a Master’s Degree in Sports Injury Management. Follow her on LinkedIn and ResearchGate.