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
One of the most frequently discussed topics in research surrounding Selective Androgen Receptor Modulators (SARMs) such as RAD-140 (Testolone) is whether they convert to other hormones — particularly oestrogen (estrogen) or dihydrotestosterone (DHT).
Understanding this question is important for researchers, as conversion into these hormones can influence outcomes related to muscle growth, recovery, and potential side effects.
So, does RAD-140 convert to oestrogen or DHT in the body? Let’s look at what the science actually shows.
How Hormonal Conversion Works
In the human body, natural testosterone can be converted into other hormones through two main enzymatic pathways:
Aromatisation (Aromatase enzyme): Converts testosterone into oestrogen.
5-Alpha-Reduction (5-alpha reductase enzyme): Converts testosterone into DHT, a more potent androgen.
Both processes occur naturally, and while oestrogen plays key roles in bone and cardiovascular health, excessive conversion can lead to unwanted effects such as water retention, mood fluctuations, or gynecomastia. Similarly, elevated DHT may contribute to hair thinning or prostate issues.
The key difference between SARMs and testosterone is how they interact — or don’t — with these conversion enzymes.
RAD-140 and Aromatisation: Does It Convert to Oestrogen?
Unlike testosterone or anabolic steroids, RAD-140 does not undergo aromatisation.
That means it does not convert to oestrogen via the aromatase enzyme pathway. This property is one of the main reasons RAD-140 is so attractive in research — it can activate androgen receptors in muscle and bone tissue without stimulating oestrogenic activity elsewhere.
Research evidence:
Preclinical studies show that RAD-140 binds selectively to androgen receptors in muscle and bone, without activating estrogen or progesterone receptors.
In trials involving non-human primates, RAD-140 increased lean mass and bone strength but showed no evidence of oestrogenic activity.
Takeaway: From a biochemical standpoint, RAD-140 is non-aromatising — meaning it does not directly increase oestrogen levels.
RAD-140 and DHT Conversion
Similarly, RAD-140 is not a substrate for the 5-alpha reductase enzyme, which means it does not convert to dihydrotestosterone (DHT).
DHT is responsible for many of the androgenic side effects associated with steroids, such as scalp hair loss, acne, and prostate enlargement. Because RAD-140 doesn’t undergo 5-alpha reduction, it avoids these conversion-related pathways.
Takeaway: In research settings, RAD-140 does not chemically convert to DHT, making it distinct from traditional androgens in its selectivity and tissue-specific effects.
If RAD-140 Doesn’t Convert, Why Do Some Studies Report Hormonal Changes?
While RAD-140 itself doesn’t convert to oestrogen or DHT, some studies have reported secondary hormonal effects — primarily a suppression of natural testosterone production after extended exposure.
Here’s why this can happen:
When RAD-140 binds strongly to androgen receptors, the body’s feedback loop perceives elevated androgenic activity.
This triggers a negative feedback response, reducing luteinising hormone (LH) and follicle-stimulating hormone (FSH) production.
Over time, this may cause lower endogenous testosterone and, consequently, downstream reductions in oestrogen (since less testosterone is available to aromatise).
In other words, RAD-140 does not convert into these hormones — it can simply influence hormonal balance indirectly through feedback mechanisms.
Read Next: The Benefits of Researching MK-677 and RAD-140 Together
Comparison With Other Compounds
To put things into perspective, let’s look at how RAD-140 behaves compared with other hormones and compounds studied in similar contexts:
Natural testosterone easily converts into both oestrogen and DHT through normal enzymatic processes. Most anabolic steroids follow a similar pattern — some converting more strongly to DHT, others more to oestrogen, depending on their structure.
By contrast, RAD-140’s molecular design prevents these conversions entirely. It doesn’t aromatise into oestrogen, and it’s not processed by the 5-alpha reductase enzyme to form DHT. This is a key distinction that helps explain its selective activity in muscle and bone tissue.
For additional context, MK-677 (Ibutamoren) — often researched alongside RAD-140 — takes an entirely different pathway, stimulating growth hormone and IGF-1 rather than interacting with androgen receptors at all.
This makes RAD-140 unique in its ability to promote anabolic-like activity without converting to oestrogen or DHT, a feature that sets it apart from many hormone-based compounds.
What the Research Says
Several published studies and reviews support RAD-140’s non-conversion profile:
Jayaraman et al., 2014 (Endocrinology): Found that RAD-140 acted selectively in muscle and bone tissue and was neuroprotective in rat models, with no measurable oestrogenic or DHT-related activity.
PubMed
Dalton et al., 2009 (Endocrine Reviews): Reviewed SARMs including RAD-140 and confirmed that these molecules are non-steroidal and do not undergo enzymatic conversion to DHT or oestrogen.
PubMed
Research Implications
Because RAD-140 does not convert to oestrogen or DHT, researchers see it as a promising model for:
Muscle preservation and lean mass studies without hormonal side effects.
Bone density research, particularly where oestrogen stimulation is undesirable.
Neuroprotective exploration, where androgenic side effects could otherwise confound results.
However, it’s important to note that temporary testosterone suppression has been observed in some research, underscoring the importance of post-study hormonal evaluation and monitoring.
Summary of Hormonal Conversion
To summarise:
Oestrogen: RAD-140 does not aromatise — meaning it doesn’t convert to oestrogen.
DHT: RAD-140 is not processed by 5-alpha reductase, so no conversion to DHT occurs.
Testosterone: Natural testosterone levels may decrease due to hormonal feedback suppression, but this is an indirect effect, not a conversion.
These distinctions make RAD-140 fundamentally different from traditional androgens or anabolic steroids that undergo these conversions.
Conclusion
From a biochemical and research perspective, RAD-140 (Testolone) does not convert to oestrogen, DHT, or any other unwanted hormones.
Its structure is specifically designed to bypass aromatisation and 5-alpha-reduction, offering targeted androgen receptor activity in muscle and bone tissue.
While RAD-140 can influence hormone levels indirectly through feedback suppression, there’s no evidence it chemically transforms into other hormones. This selectivity continues to make it a valuable compound for studying muscle, bone, and neuroprotective effects in controlled research environments.
Interested in the potential results of researching with RAD-140? Find out What to Expect from a Research Perspective