RAD-140.

Quick Overview.

RAD-140, commonly known as Testolone, is a highly potent Selective Androgen Receptor Modulator (SARM) originally developed by Radius Health Inc. It was designed as a potential treatment for muscle wasting and, notably, as a targeted therapy for certain types of breast cancer. In the bodybuilding and fitness communities, it is widely considered the strongest SARM available for building "dry" muscle mass and increasing sheer strength.[1][2]

If LGD-4033 is the "wet mass" builder, RAD-140 is the "dry strength" builder. It binds to the androgen receptor with an affinity that rivals or exceeds that of testosterone itself. Because of its extreme potency, it produces rapid increases in strength and muscle density, but it also comes with severe testosterone suppression, increased aggression, and significant liver stress.[3]

• Primary Use Case: Rapid strength gains, dry muscle mass accumulation, and body recomposition.
• Mechanism: Highly selective, high-affinity agonism of the androgen receptor in skeletal muscle and bone.[4]
• Who it is for: Advanced users looking for steroid-like strength gains without the water retention of LGD-4033.
• Who it is NOT for: Beginners, women (due to high virilization risk), or anyone prone to hair loss or anger issues.

The Protocol & Usage Guide.

confidence_tier: well-established

RAD-140 is orally bioavailable. While its half-life was originally thought to be 24 hours, more recent pharmacokinetic data suggests it may have a half-life closer to 60 hours. Despite this, it is still typically dosed once per day.[5]

Standard Dosing Schedule

Cycle Length & Discontinuation Protocol

• Cycle Length: 6 to 8 weeks. Do not exceed 8 weeks. The side effects (suppression, liver stress, hair shedding) compound rapidly after week 6.
• Discontinuation (PCT): RAD-140 is severely suppressive. A full Post Cycle Therapy (PCT) using Enclomiphene (12.5mg daily for 4 weeks) or Nolvadex (20mg daily for 4 weeks) is absolutely mandatory to restore natural testosterone production.[6]

Nutritional Support & Recommended Supplements.

confidence_tier: well-established

Safety, Interactions & Side Effect Management.

confidence_tier: well-established

Side Effect Profile

Contraindications

• Absolute: Individuals with pre-existing liver disease or severe cardiovascular issues.
• Absolute: Teenagers whose endocrine systems are still developing.
• Relative: Individuals prone to male pattern baldness or anger management issues.

Drug Interactions

• Alcohol: Severe. Combining RAD-140 with alcohol places immense stress on the liver and significantly increases the risk of drug-induced liver injury (DILI).
• Accutane / Hepatotoxic Drugs: Severe. Do not stack with other liver-toxic medications.

Common Stacks & Combinations.

confidence_tier: community

Body Composition & Training Guide.

confidence_tier: community

• The Strength King: RAD-140 is famous for producing rapid, almost steroid-like increases in strength. Users frequently report adding 20-40 lbs to their compound lifts within a 6-week cycle.
• The "Dry" Look: Unlike LGD-4033, which causes water retention, RAD-140 pulls water out of the subcutaneous layer, giving the muscles a hard, dense, and vascular appearance.
• CNS Fatigue: Because RAD-140 allows users to lift significantly heavier weights very quickly, the central nervous system (CNS) and tendons often struggle to keep up. Users must be careful not to tear a muscle or tendon due to rapid strength increases.

Storage, Handling & Accessibility.

confidence_tier: well-established

• Storage: Store liquid solutions or capsules at room temperature in a cool, dark place.
• WADA Status: Banned in competitive sports under section S1.2 (Other Anabolic Agents). It has a long detection window.
• Cost & Accessibility: Widely available from research chemical vendors. Typically costs $50-$80 for a 30mL bottle (usually dosed at 10mg/mL).

Bloodwork Monitoring Guide.

confidence_tier: well-established

Comparison to Similar Compounds.

confidence_tier: well-established

Deep Dive (For Advanced Researchers).

confidence_tier: well-established

Mechanism of Action

RAD-140 is a non-steroidal selective androgen receptor modulator. It binds to the androgen receptor (AR) with an extremely high affinity (Ki = 7 nM), which is roughly equivalent to the binding affinity of dihydrotestosterone (DHT). It acts as a full agonist in skeletal muscle and bone, but acts as a partial agonist (or even an antagonist) in the prostate and seminal vesicles.[7]

Clinical Trial Summary

Unlike Ostarine and LGD-4033, which were primarily studied for muscle wasting, RAD-140's clinical development pivoted heavily toward oncology.

• Breast Cancer Efficacy: In preclinical models and a Phase I human trial, RAD-140 was shown to be highly effective at inhibiting the growth of Androgen Receptor-positive (AR+) / Estrogen Receptor-positive (ER+) breast cancer. It does this by binding to the AR and repressing the ESR1 gene, effectively starving the cancer cells of estrogenic signaling.[8][9]
• Neuroprotection: In rat models, RAD-140 demonstrated significant neuroprotective effects. It was shown to protect hippocampal neurons against apoptosis induced by amyloid-beta (the protein associated with Alzheimer's disease) as effectively as testosterone, but without the peripheral androgenic side effects.[10]

Pharmacokinetics & Half-Life

Early literature cited a 24-hour half-life for RAD-140. However, a 2022 pharmacokinetic study analyzing micro-dosed RAD-140 in humans found that the terminal elimination half-life is actually closer to 60 hours. This means the drug accumulates significantly in the body over a cycle, which explains why side effects often become severe around week 4 or 5.[11]

Hepatotoxicity

RAD-140 is increasingly recognized in medical literature as a significant cause of drug-induced liver injury (DILI). Multiple case reports detail young men presenting with severe jaundice, pruritus (itching), and highly elevated liver enzymes (AST/ALT) after using RAD-140 for 4 to 8 weeks. The liver injury is typically characterized as cholestatic (impaired bile flow) and can take months to fully resolve.[12][13]

Frequently Asked Questions (FAQ).

confidence_tier: community

Q: Will RAD-140 make my hair fall out? A: It is highly possible. RAD-140 is notorious in the community for causing hair shedding. If you are genetically predisposed to male pattern baldness, RAD-140 will likely accelerate it.

Q: Do I really need a PCT for RAD-140? A: Absolutely. RAD-140 is severely suppressive. At bodybuilding doses (10-20mg), your natural testosterone production will be shut down. A SERM PCT is mandatory.

Q: Why am I so angry on RAD-140? A: RAD-140 is known to cause increased aggression, irritability, and insomnia in some users. This is likely due to its extremely high binding affinity to androgen receptors in the brain, mimicking the psychological effects of high-dose androgens.

International Regulatory Status.

confidence_tier: well-established

Decision Tree.

confidence_tier: community

[Goal: Maximum Strength and Dry Muscle Mass?]
  |
  +-- Are you prone to hair loss or anger issues?
        |
        +-- (Yes) -> Avoid RAD-140. Consider Ostarine or LGD-4033.
        |
        +-- (No) -> Are you willing to run a full PCT?
              |
              +-- (Yes) -> Take 10mg daily for 6-8 weeks.
                           Take Liver Support (NAC) daily.
                           Follow with 4 weeks of Enclomiphene (PCT).

Schema.org Data.

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  "@type": "MedicalEntity",
  "name": "RAD-140",
  "alternateName": ["Testolone"],
  "description": "A highly potent, non-steroidal selective androgen receptor modulator (SARM) investigated for breast cancer and muscle wasting, widely used off-label for rapid increases in strength and dry muscle mass.",
  "legalStatus": {
    "@type": "DrugLegalStatus",
    "description": "Investigational new drug. Not FDA approved. Banned by WADA."
  }
}

What we cited.