LGD-4033 vs Testosterone
Moderate Research vs FDA Approved
monitor Researched · 90% LGD-4033 causes dose-dependent suppression of endogenous testosterone through HPG axis negative feedback. Some users run a low-dose testosterone base (e.g., 100-150 mg/week TRT) alongside LGD-4033 to prevent suppression-related side effects such as low libido, lethargy, fatigue, and mood disturbance. If combining, monitor total testosterone, free testosterone, estradiol, and SHBG levels. Adding exogenous testosterone converts this from a SARM-only cycle to a testosterone cycle with regulatory and health implications.
Molecular Data
LGD-4033 Testosterone
Weight 338.25 Da 288.42 Da (base)
Half-life ~24-36 hours ~8 days (cypionate)
Type Nonsteroidal selective androgen receptor modulator (C14H12F6N2O) Steroid hormone (C19H28O2)
Key Benefits
LGD-4033
01 Strongest SARM for lean muscle mass accrual, with clinical trial data supporting dose-dependent increases in lean body mass
02 Tissue-selective action with minimal stimulation of the prostate and other androgen-sensitive tissues
03 Clinical evidence of improved physical function (leg press strength, stair-climbing speed) in hip fracture patients
04 No aromatization to estrogen (no estrogen-related water retention or gynecomastia at the receptor level)
05 No conversion to DHT (reduced risk of androgenic hair loss and prostate stimulation compared to testosterone)
06 Convenient once-daily oral dosing due to 24-36 hour half-life
07 Phase 2 clinical data available, providing a stronger evidence base than most other SARMs
Testosterone
01 Restoration of normal testosterone levels in hypogonadal men
02 Increased lean muscle mass and strength
03 Improved bone mineral density and reduced fracture risk
04 Enhanced libido, sexual function, and erectile quality
05 Improved mood, energy, motivation, and cognitive clarity
06 Reduction in body fat percentage, particularly visceral fat
07 Increased red blood cell production and oxygen-carrying capacity
08 Improved insulin sensitivity and metabolic health markers
Dosing Protocols
LGD-4033
5-10 mg/day / Once daily (oral)
Testosterone
100-200 mg/week (TRT) / 1-2x per week (injectable)
TRT - Standard Replacement 100-200 mg/week 1-2x per week
TRT - Conservative Start 80-100 mg/week 2x per week (40-50 mg per injection)
TRT - Propionate Protocol 25-50 mg every other day Every other day or 3x per week
Performance Enhancement - Moderate 300-500 mg/week 2x per week
Performance Enhancement - Advanced 500-750 mg/week 2-3x per week
Side Effects
LGD-4033
Testosterone suppression (dose-dependent; more suppressive than Ostarine at equivalent doses, occurs in most users by week 4-6)
Water retention (non-estrogenic mechanism, typically mild to moderate, contributes to scale weight increase)
HDL cholesterol reduction (dose-dependent lipid impact observed in clinical trials)
Headaches (most common in the first 1-2 weeks, usually transient)
Fatigue or lethargy (related to testosterone suppression, typically becomes noticeable mid-cycle)
Reduced libido (related to HPG axis suppression, severity varies by dose and individual)
Testosterone
Acne and oily skin (increased sebum production via DHT)
Water retention and bloating (estrogen-mediated)
Mild mood changes (irritability, increased assertiveness)
Increased hematocrit and hemoglobin (erythrocytosis)
Testicular atrophy (suppression of LH/FSH from exogenous testosterone)
Injection site pain, redness, or irritation
Increased body hair growth
Mild elevation in blood pressure
Contraindications
Pre-existing liver disease or elevated liver enzymes at baseline
Hormone-sensitive cancers (prostate cancer or other androgen-driven malignancies)
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 long-term safety data for this population)
History of significant lipid abnormalities (LGD-4033 suppresses HDL)
Prostate cancer (active or history of hormone-sensitive prostate cancer)
Breast cancer in males
Polycythemia (hematocrit above 54% at baseline)
Uncontrolled severe heart failure
Untreated severe obstructive sleep apnea
Desire for near-term fertility (without concurrent HCG/FSH)
Pregnancy or potential exposure to pregnant women (Category X)
Hypersensitivity to testosterone or any formulation components
Research Evidence
LGD-4033 Testosterone
Status Moderate Research FDA Approved
References 5 studies 5 studies
Latest 2018 June 2023
FDA Approved No Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.