LGD-4033 vs Rapamycin
Moderate Research vs FDA Approved
monitor Mechanism-based · 47% Both LGD-4033 and Rapamycin negatively affect lipid profiles. Combined use may significantly worsen HDL/LDL ratios. Include lipid support and get bloodwork mid-cycle.
Molecular Data
LGD-4033 Rapamycin
Weight 338.25 Da 914.17 Da
Half-life ~24-36 hours ~62 hours
Type Nonsteroidal selective androgen receptor modulator (C14H12F6N2O) Macrolide lactone (C51H79NO13)
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
Rapamycin
01 Lifespan extension demonstrated in every model organism tested (yeast, worms, flies, mice)
02 Upregulation of autophagy and cellular quality control mechanisms
03 Reduction of senescent cell burden and associated inflammatory secretome
04 Improved immune function at low pulsed doses (paradoxical immune enhancement)
05 Reduced age-related inflammation (inflammaging) via mTORC1 inhibition
06 Enhanced mitochondrial function and biogenesis
07 Potential reduction in age-related cancer risk through growth pathway suppression
08 Improved vaccine response in elderly populations at low intermittent doses
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)
Rapamycin
Mouth sores / aphthous ulcers (most common, usually dose-dependent and self-limiting)
Mild lipid changes (elevated LDL cholesterol and triglycerides)
Temporary glucose elevation or mildly impaired fasting glucose
Mild gastrointestinal discomfort (nausea, loose stools)
Skin changes (mild acne, slower wound healing at injection/cut sites)
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)
Active serious infection or immunocompromised state
Hypersensitivity to rapamycin/sirolimus or any macrolide compound
Severe hepatic impairment (rapamycin is extensively hepatically metabolized)
Planned major surgery within 2-4 weeks (impaired wound healing)
Pregnancy or breastfeeding
Concurrent use of strong CYP3A4 inhibitors without dose adjustment (ketoconazole, itraconazole, clarithromycin, grapefruit juice)
Research Evidence
LGD-4033 Rapamycin
Status Moderate Research FDA Approved
References 5 studies 5 studies
Latest 2018 March 2023
FDA Approved No Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.