Prohormones vs SARMs: How They Differ and Why Both Carry Risk
Both were sold as legal or safer alternatives to steroids. Many prohormones turned out to be oral steroids by another name, and SARMs carry their own uncertainties.
SteroidsCanada.org editorial teamUpdated · 2 min read
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In the late 1990s and 2000s, “prohormones” filled supplement shelves as a legal path to steroid-like results. Regulators caught up, and many disappeared or were reformulated. SARMs took their place in the marketing. The two groups are often lumped together, but they work differently, and both carry risks that are easy to underestimate.
What prohormones are
A true prohormone is a precursor that the body converts into an active hormone. Androstenedione and DHEA are examples: enzymes turn them partly into testosterone, and also into estrogen. Studies of androstenedione in men found small or no increases in testosterone with substantial increases in estrogen, the opposite of what buyers wanted.
Later “designer” prohormones were different. Products such as methyldrostanolone (sold as Superdrol) and methasterone analogues were active anabolic steroids, often 17-alpha-alkylated, sold under supplement labels.
Side by side
| Prohormones / designer steroids | SARMs | |
|---|---|---|
| Structure | Steroidal | Mostly non-steroidal |
| How they act | Converted to, or act as, anabolic steroids | Bind the androgen receptor directly, selectively |
| Estrogen/DHT conversion | Often yes, depending on compound | No |
| Liver | Many are 17-alpha-alkylated: high risk | Lower on average, but injury reported |
| HDL cholesterol | Large drops | Moderate drops |
| Suppression | Yes | Yes |
| Canadian status | Often Schedule IV anabolic steroids | Unapproved; Health Canada warnings |
The liver problem with designer prohormones
Case series from the 2000s and 2010s described severe cholestatic liver injury and kidney injury in young men taking supplements containing designer steroids, sometimes requiring hospital care. Because labels were vague or wrong, many did not realise they were taking oral steroids at all.
Product quality
Both categories suffer from labelling problems. Laboratory testing has found SARM products with the wrong compound or dose, and supplements containing undeclared steroids. A product with no named manufacturer, batch number or Health Canada NPN deserves extra caution.
Legal status in Canada
Many prohormone compounds fall under Schedule IV of the Controlled Drugs and Substances Act as anabolic steroids. SARMs are not approved for human use. Both are prohibited in sport, and contaminated supplements have caused positive tests for athletes who did not knowingly take them.
A short history
Androstenedione became famous in the late 1990s when a home run record-chaser was seen with it. The United States reclassified it and many related compounds as controlled anabolic steroids in 2004, and manufacturers responded with new designer molecules that were not yet named in the law. Regulators added those in turn. In Canada, broad wording in Schedule IV captures many of these compounds as anabolic steroids.
Practical takeaway
Neither group is a safe or natural shortcut. If you are comparing options, understand what each compound actually is, check liver enzymes and lipids, and be wary of anything sold as a legal steroid. See also SARMs versus steroids and oral steroids explained.
Products in this guide
Each product page carries the chemistry, label strength, risks and references.
Questions
What is a test booster?
Most over-the-counter test boosters contain herbs, zinc or vitamin D and have little effect on testosterone in healthy men. Some products have been found to contain undeclared steroids.
Can I pass a drug test after taking prohormones?
Many prohormones and designer steroids are detectable for weeks or longer, and athletes have tested positive from contaminated supplements.
Is Superdrol a prohormone?
Methyldrostanolone was marketed as a prohormone in the 2000s but is an active, 17-alpha-alkylated anabolic steroid. It is linked to significant liver injury.
Are prohormones legal in Canada?
Many prohormone compounds are listed or captured as anabolic steroids under Schedule IV of the Controlled Drugs and Substances Act.
Do prohormones convert to estrogen?
Some do, depending on the parent compound. Androstenedione, for example, can raise estrogen considerably.
Are SARMs better than prohormones?
They are less toxic to the liver on average, but not free of liver injury, and they still suppress natural testosterone.
Sources
General information, not medical advice. Written for adults in Canada. Anabolic steroids are Schedule IV under the Controlled Drugs and Substances Act. Talk to a licensed healthcare provider and get bloodwork before using any compound.
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