SARMs vs Prohormones

SARMs and prohormones are often part of the same conversations. And for good reason. According to research, both chemical substances can have a similar sort of effect on muscle mass and strength. However, while some people say that the difference between them is merely linguistics, there are some notable ways that SARMs and prohormones are distinct from one another. But which is best? Below, we’re setting out to answer the SARMs vs prohormones debate with science. 

SARMs: What are SARMs?

Firstly, it’s important to understand what SARMs and prohormones actually are. SARMs, as you may already know, are Selective Androgen Receptor Modulators. They have a similar effect to anabolic steroids, but with one big difference. As SARMs are selective, they only bind to specific androgen receptors, thereby reducing the androgen effects (such as reduced testicle size and acne) without compromising on the desired anabolic effects (such as increased muscle mass and strength). 

SARMs are completely synthetic, engineered as a potential treatment for muscle weakness and muscle wasting caused by conditions such as sarcopenia, cancer, osteoporosis, and muscular dystrophy. SARMs have been associated with results such as improved bone density, increased strength, muscle growth, and higher cognition. Unlike injectable steroids, SARMS are typically available as tablets, or as capsules. 

Prohormones: What are Prohormones?

Prohormones are natural substances that are produced by the body. They are precursors of regular hormones, and are considered to be an inactive form of that hormone. The body is able to activate these prohormones on demand, turning them into full hormones as and when the body requires an increase in that particular hormone. It’s a way for the body to regulate hormone expression for optimal results. 

However, in the SARMs vs prohormones debate, the type of prohormones we’re referring to are not natural prohormones, but synthetic alternatives. Drug manufacturers have mimicked natural prohormones with engineered versions that essentially do the same thing: they convert to active hormones in the body to increase the amount of that hormone available. For example, a prohormone can be manufactured to be a precursor to testosterone. In the body, an enzymatic process converts it to an active hormone, giving the body a testosterone boost. 

As low levels of testosterone in males has been associated with undesirable changes in body composition, enhancing testosterone availability in the body through prohormones could result in greater satisfaction with one’s fitness and appearance. Prohormones of different types are usually available in a capsule form. 

Which is More Effective?

While much more research needs to be done on both SARMs and prohormones, there is evidence to support the effectiveness of both types of chemical substance.

Studies have found that SARMs are capable of stimulating muscle growth in much the same way as anabolic steroids, but with a lower risk of unwanted side effects and less impact on sex hormones. At the same time, prohormones such as norandrostenedione have been shown to enhance growth in the skeletal muscle selectively, without sparking the same undesirable androgenic effects of steroids. 

Ultimately, in terms of overall effectiveness, SARMs and prohormones are very similar. Experts have even concluded that ‘the prohormone 19-norandrostenedione displays selective androgen receptor modulator (SARM) like properties’. 

Which is Safer?

Once again, much more research is needed to fully determine the safety profiles of both SARMs and prohormones, and conclude which is the safest chemical to use. 

SARMs are generally considered to be safe, and it is widely accepted that SARMs are, at the very least, safer than anabolic steroids. However, that doesn’t make them magical solutions. Studies have found that more than 50% of male participants have experienced some form of undesirable side effect from using SARMs, with the most notable side effects being mood swings, acne, and reduced testicle size.  

It’s possible that the side effects when taking prohormones could be even more pronounced. One study found that prohormones could result in an increase in ‘bad’ cholesterol (low-density lipoprotein, or LDL), and a reduction in ‘good’ cholesterol (high-density lipoprotein, or HDL). This same study also warned of the potential for prohormones to impair kidney and liver function, and increase risk of renal failure. 

Therefore, while it is irresponsible to say that SARMs are 100% safe, the research available to date does suggest SARMs are perhaps slightly safer than prohormones. 

Are SARMs and Prohormones Legal?

Yes. Both SARMs and prohormones are legal to purchase in the UK. 

SARMs are currently classified as research chemicals, which means that they can be purchased legally by adults. However, they currently are not approved by either the European Medicines Agency (EMA) or the Food and Drink Administration (FDA). SARMs cannot be legally used for competitive sport, with all types of SARMs falling under the ‘other anabolic agents’ category in the WADA official prohibited list

Unlike SARMs, prohormones are approved by the FDA, and are classified as dietary supplements. This is because they contain compounds that occur naturally in the human body. For this reason, prohormones are slightly less regulated than SARMs. However, just like SARMs, they are still banned by many sporting bodies. The International Olympic Committee, for example, has banned all prohormones. 

SARMs vs Prohormones: A Summary

To summarise the similarities – and differences – between SARMs and prohormones…


  • Chemically engineered
  • Developed to treat muscle wasting symptoms
  • Triggers changes directly in a person’s DNA
  • Scientific evidence for muscle growth
  • Can cause side effects, mostly minor
  • Available in tablet or capsule form
  • Legal as a research chemical
  • Banned by major sporting bodies
  • Available to purchase online


  • Chemically engineered
  • Developed to mimic natural compounds in the body
  • Works by supercharging natural hormone levels
  • Scientific evidence for muscle growth
  • Can cause side effects, possibly significant
  • Available in capsule form
  • Legal as a dietary supplement
  • Banned by major sporting bodies
  • Available to purchase online

The truth is that both SARMs and prohormones are very similar, both having the same sort of effect on muscle mass, cell growth, and strength. However, they work in different ways, are classified differently, and spark different reactions in users.