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January 26, 2026

What Is RAD-140?

What Is RAD-140?

In the world of performance research, few compounds have generated as much scientific interest as Selective Androgen Receptor Modulators. And among SARMs, RAD-140 (Testolone) stands out as one of the most potent and well-studied.

But what exactly is RAD-140? What does the research show? And why has it become such a focus of scientific investigation?

What Is RAD-140?
RAD-140, also known as Testolone, is a Selective Androgen Receptor Modulator developed by Radius Health Inc. Unlike traditional androgens, SARMs are designed to selectively target androgen receptors in specific tissues—primarily muscle and bone—while minimising activity in other androgen-sensitive tissues.

The Science of Selective Targeting

90:1
Anabolic Ratio
SARM
Classification
Oral
Bioavailability

The key innovation of SARMs lies in their tissue selectivity. Traditional androgens like testosterone affect every tissue with androgen receptors. SARMs, by contrast, are designed to preferentially activate receptors in muscle and bone while having reduced activity elsewhere.

Research indicates RAD-140 demonstrates one of the highest selectivity ratios among studied SARMs—meaning its anabolic-to-androgenic ratio in experimental models is particularly favourable.


What Research Shows

🎯
Selective Receptor Binding

Studies demonstrate that RAD-140 binds to androgen receptors with high affinity. Research published in peer-reviewed journals shows it activates receptors in muscle tissue while showing reduced activity in prostate tissue—the hallmark of SARM selectivity.

High-affinity, tissue-selective binding documented

💪
Anabolic Activity

Preclinical research has examined RAD-140's effects on lean mass in animal models. Studies show significant anabolic activity—increases in lean body mass comparable to testosterone but with a more favourable selectivity profile.

Anabolic effects documented in research models

🧠
Neuroprotective Research

Emerging studies have investigated RAD-140's potential neuroprotective properties. Research suggests it may have protective effects in neuronal cell models—an area of significant scientific interest given the role of androgens in brain health.

Neuroprotection pathway research ongoing

🦴
Bone Tissue Studies

Research has examined RAD-140's effects on bone tissue. Studies indicate anabolic activity in bone—potentially relevant for research into conditions involving bone loss.

Bone anabolic activity observed in studies

Key Research Finding
In preclinical studies, RAD-140 demonstrated anabolic activity in muscle and bone tissue while showing significantly reduced activity in prostate tissue compared to testosterone. This tissue-selective profile is what distinguishes SARMs from traditional androgens in research.

RAD-140 vs. Traditional Androgens

Factor RAD-140 Testosterone
Administration Oral Injection/Topical
Tissue Selectivity High (muscle/bone preferential) Non-selective
Prostate Activity Reduced in studies Full androgenic effect
Aromatisation Does not aromatise Converts to estrogen
Research Stage Investigational Established

How RAD-140 Works

  1. Binds to Androgen Receptors - Selectively attaches to AR in target tissues
  2. Tissue-Selective Activation - Preferentially activates receptors in muscle and bone
  3. Reduced Off-Target Activity - Shows lower activity in prostate and other tissues
  4. No Aromatisation - Does not convert to estrogen like testosterone
  5. Oral Bioavailability - Active when taken orally, unlike many androgens

Areas of Scientific Interest

Researchers continue to investigate RAD-140 across multiple domains:

  • Muscle wasting conditions - Original development focus
  • Sarcopenia research - Age-related muscle loss
  • Bone density studies - Potential bone-protective effects
  • Neuroprotection - Brain health and androgen receptor activity
  • Breast cancer research - Radius Health's clinical focus
⚠️ Research Compound Notice
RAD-140 is sold for research purposes only. It is not approved for human consumption and is not a dietary supplement. This article summarises published scientific research for educational purposes. All research should be conducted by qualified personnel in appropriate laboratory settings.

Why RAD-140 Interests Researchers

The scientific interest in RAD-140 comes down to its unique profile:

  • High selectivity ratio - Among the most selective SARMs studied
  • Oral bioavailability - Convenient for research protocols
  • Well-characterised - Extensive preclinical data available
  • Multiple research applications - Muscle, bone, and neuro studies
  • Favourable pharmacokinetics - Suitable half-life for research

For researchers investigating androgen receptor biology, tissue-selective compounds, or anabolic mechanisms, RAD-140 represents one of the most studied tools available.

Research-Grade RAD-140
UK made. Lab tested. 99%+ purity verified by HPLC. Certificate of Analysis available.
View RAD-140 →
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