Naltrexone vs RAD-140
FDA Approved vs Emerging
avoid Mechanism-based · 53% Both Naltrexone and RAD-140 carry hepatotoxic risk. Combining hepatotoxic compounds significantly increases liver damage potential. If unavoidable, include liver support (TUDCA/NAC) and monitor ALT/AST frequently.
Molecular Data
Naltrexone RAD-140
Weight 341.40 Da 393.83 Da
Half-life ~4 hours ~60 hours
Type Opioid antagonist (C20H23NO4) Nonsteroidal selective androgen receptor modulator (C20H16ClN5O2)
Key Benefits
Naltrexone
01 Broad anti-inflammatory and immunomodulatory effects via OGF-OGFr axis upregulation
02 Reduction in pro-inflammatory cytokines (TNF-alpha, IL-6, IL-12) through TLR4 antagonism
03 Compensatory upregulation of endogenous endorphins and enkephalins (200-300% increase)
04 Improved immune regulation and rebalancing of Th1/Th2/Th17 responses
05 Reduction in chronic pain through central and peripheral opioid system modulation
06 Potential improvement in mood, anhedonia, and overall well-being via endorphin enhancement
07 Extremely well-tolerated with minimal side effects at low doses
08 Low cost, especially as compounded LDN formulation
RAD-140
01 Potent anabolic activity in muscle tissue with high oral bioavailability
02 Tissue-selective action sparing the prostate and other androgen-sensitive organs
03 No aromatization to estrogen (no estrogen-related side effects such as water retention or gynecomastia)
04 No conversion to DHT (reduced risk of hair loss and prostate stimulation compared to testosterone)
05 Long half-life (~60 hours) permitting convenient once-daily oral dosing
06 Neuroprotective properties observed in preclinical models
07 Increased lean body mass and reduced fat mass in preclinical studies
Side Effects
Naltrexone
Vivid dreams or unusually intense dreaming - the most frequently reported side effect, typically diminishes over 1-2 weeks
Initial sleep disruption or insomnia during the first week of treatment
Mild nausea, particularly during the first few days
Transient headache during dose initiation or titration
RAD-140
Testosterone suppression (dose-dependent, occurs in virtually all users by week 4-6)
Liver enzyme elevation (ALT, AST increases reported in clinical and anecdotal data)
Hair shedding (temporary, typically resolves after discontinuation)
Headaches (most common in the first 1-2 weeks, often transient)
Nausea (mild, usually with initial doses or on an empty stomach)
Lipid disruption (HDL suppression, LDL elevation)
Mild insomnia or sleep disturbance
Reduced libido and mood changes related to testosterone suppression
Contraindications
Current use of opioid medications or active opioid dependence (must be opioid-free 7-10 days minimum)
Acute hepatitis or severe hepatic impairment (primarily relevant at full dose)
Known hypersensitivity to naltrexone
Anticipated need for opioid pain medication (e.g., upcoming surgery - discontinue LDN 3-7 days prior)
Pre-existing liver disease or elevated liver enzymes at baseline
Hormone-sensitive cancers (prostate cancer, certain breast cancers not being treated under clinical supervision)
Pregnancy or potential pregnancy (teratogenic risk from androgen receptor agonism)
Breastfeeding
Age under 25 (incomplete endocrine system maturation and higher risk of HPG axis disruption)
Concurrent use of hepatotoxic medications without medical supervision
Known cardiovascular disease (insufficient safety data for this population)
Research Evidence
Naltrexone RAD-140
Status FDA Approved Emerging
References 5 studies 5 studies
Latest 2023 July 2020
FDA Approved Yes No
This comparison is for educational and research purposes only. Consult a healthcare professional before use.