Disclaimer: This article is for educational purposes only. RAD-140 (Testolone) is sold strictly for research purposes only and is not approved for human consumption.
Introduction
RAD-140, also known as Testolone, has quickly become one of the most widely studied selective androgen receptor modulators (SARMs). Its high anabolic potential and strong binding affinity to androgen receptors have made it an exciting compound for researchers looking into muscle growth, strength, and performance.
But alongside its benefits, there is an equally important question: what are the side effects of RAD-140? While RAD-140 was designed to minimise unwanted androgenic activity compared to anabolic steroids, it is not free from risks. This article explores the side effects that have been observed in research settings, how they may vary by dosage, and why understanding them is essential for safe and responsible studies.
Hormonal Suppression
One of the most consistent findings in RAD-140 research is its potential to suppress natural testosterone production.
Mechanism: RAD-140 strongly binds to androgen receptors, signalling the body that it has sufficient androgenic activity. As a result, the hypothalamic-pituitary-gonadal axis (HPGA) reduces its production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
Outcome in research: Lower natural testosterone levels, which may lead to reduced energy, libido, or muscle retention after discontinuation.
Research implications: Many studies pair RAD-140 cycles with investigations into PCT support, such as Enclomiphene, to better understand recovery outcomes.
Liver and Lipid Profile Changes
While RAD-140 is non-methylated (making it easier on the liver compared to oral steroids), some research and anecdotal reports have suggested mild liver enzyme elevations during studies.
Liver enzymes (ALT, AST): Increases may indicate added stress on the liver.
Cholesterol shifts: Some studies note lowered HDL (good cholesterol) and elevated LDL (bad cholesterol), particularly at higher doses.
These changes highlight the need for ongoing monitoring in controlled research environments.
Mood, Energy, and Sleep Disturbances
Another category of side effects noted in research and anecdotal studies includes:
Irritability or aggression – likely tied to androgen receptor activity.
Fatigue or “crashes” – particularly towards the end of a research protocol.
Sleep disruption – some researchers report difficulty falling or staying asleep.
Interestingly, other compounds such as MK-677 have been studied for their positive effects on sleep, suggesting potential for complementary research.
Other Potential Risks
Because RAD-140 is relatively new, long-term side effect data is still lacking. Current gaps in knowledge include:
Cardiovascular health – limited data exists on its impact over long durations.
Prostate health – while RAD-140 was designed to reduce androgenic activity in the prostate, long-term studies are incomplete.
Neuroprotection – some research has suggested RAD-140 could protect brain cells, but its long-term neurological impact is still being studied.
Side Effects by Dosage
Research suggests that the likelihood and severity of side effects may correlate with dosage:
Low-range dosing (5–10 mg/day): Milder suppression, fewer reported issues.
Moderate dosing (10–15 mg/day): More noticeable suppression, potential for lipid changes.
High-range dosing (15–20+ mg/day): Higher risk of testosterone shutdown and adverse lipid/liver markers.
This is why dosage exploration remains one of the most studied aspects of RAD-140.
Read Next: RAD-140 Dosage in Research: What Studies Are Exploring
Why Understanding Side Effects Matters
RAD-140 continues to attract attention in 2025 because of its potential for lean muscle growth and strength support. But without understanding the risks and side effects, research into its applications would be incomplete.
Future studies are especially needed in areas like:
Long-term safety monitoring
Hormonal recovery strategies post-use
Comparisons with other SARMs (e.g., LGD-4033, Ostarine)
Where to Source Research-Grade RAD-140
For those conducting legitimate SARMs research, sourcing from a trusted, lab-tested supplier is essential. At Affordable Nutrition, we provide RAD-140 capsules with verified purity, shipped quickly within the UK.
All products are intended strictly for research purposes only.
Conclusion
RAD-140 offers exciting anabolic potential, but like any research compound, it is not without side effects. Hormonal suppression, changes in liver and lipid markers, and mood disturbances are among the most reported issues in studies so far.
By continuing to study RAD-140 in controlled environments — and pairing research with recovery compounds like Enclomiphene — scientists can better understand both its benefits and risks.
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