LGD-4033

Selective androgen receptor modulator. Demonstrates high affinity and selectivity for the androgen receptor. In Phase I trials, demonstrated dose-dependent increases in lean body mass, decreases in body fat, and increases in stair-climbing power. Phase I also demonstrated dose-dependent suppression of testosterone, FSH, and LH.

Non-steroidal oral compound. No ester. Once-daily oral dosing due to 24-36 hour half-life.

LGD-4033 is the SARM most commonly used for lean mass building in performance settings. Phase I clinical data showing dose-dependent lean mass increases gave it credibility that most other SARMs lack, which is why it is frequently cited as the most studied and most reliably effective SARM for muscle gain. Athletes and bodybuilders use it in bulking and recomposition phases, particularly those who want meaningful size increases without injectable administration. Its longer half-life allows once-daily oral dosing and its relatively fast onset compared to longer anabolic cycles makes it appealing for people who want to assess results within a standard eight to twelve week window.

LGD-4033 is sometimes combined with MK-677 in a stack that targets both androgen receptor-mediated muscle growth and growth hormone axis stimulation. This combination is frequently discussed in SARM communities as a way to maximize lean mass gains without injectables. It is also occasionally run alongside Cardarine, though Cardarine's abandoned development history makes that combination a particularly high unknown-risk pairing. LGD-4033 is rarely combined with traditional anabolics by users who have specifically chosen SARMs as an alternative to injectable steroid use.

• Phase II trials for hip fracture recovery (VK5211)
• Investigated for muscle wasting and osteoporosis
• Published Phase I data available — small sample sizes

• Testosterone suppression — documented in Phase I at all doses tested
• HDL cholesterol reduction
• Liver enzyme elevation — documented cases
• Headaches reported in trials
• Fatigue and lethargy during use and recovery
• Unknown long-term effects — no Phase III completion

LGD-4033 produces the most pronounced testosterone suppression of the commonly used SARMs. Phase I data documented dose-dependent suppression of testosterone, LH, and FSH at every dose tested. Recovery without intervention takes weeks to months and some users report prolonged suppression that requires medical management. HDL cholesterol reduction is documented. Multiple athlete disqualifications have involved LGD-4033, including high-profile cases where athletes claimed contamination, illustrating both the effectiveness of current WADA testing and the risks in the unregulated supplement supply chain where contamination is a genuine possibility.

Approximately 3 weeks via targeted WADA testing. Several athlete disqualifications have involved LGD-4033.