Last updated: March 2026
1.21kg of lean mass in just 21 days at 1mg/day — the Phase 1 data that put Ligandrol on the map. Stronger than Ostarine, more suppressive, and still nowhere near FDA approval. Here's the research.
LGD-4033 is a non-steroidal SARM with high affinity and selectivity for the androgen receptor. It demonstrates stronger binding affinity than Ostarine, which translates to more potent anabolic effects at lower doses — but also more pronounced hormonal suppression.
LGD-4033 binds the androgen receptor with a Ki of approximately 1 nM — among the highest affinities of any SARM. This tight binding translates to potent activation of anabolic pathways in muscle and bone at very low doses (effects visible at 0.3mg/day in trials). The selectivity ratio favors muscle over prostate, but less so than Ostarine.
The Basaria Phase 1 trial showed a clear dose-response: 0.1mg (+0.2kg LBM), 0.3mg (+0.6kg LBM), 1.0mg (+1.21kg LBM) over just 21 days. This linear response at low doses suggests even higher gains at research doses (5-10mg), though no controlled data exists at these levels. Mechanism involves enhanced nitrogen retention and mTOR pathway activation.
Viking Therapeutics is developing VK5211 (LGD-4033) specifically for recovery from hip fracture surgery. The rationale: SARMs can preserve and build lean mass during the immobilization period after surgery, potentially reducing recovery time and fall risk. Phase 2 hip fracture trials showed positive results on lean body mass endpoints.
LGD-4033 causes significant dose-dependent suppression of the hypothalamic-pituitary-gonadal axis. At 1mg/day for 21 days, total testosterone dropped ~50%, free testosterone dropped ~40%, and LH and FSH were significantly reduced. This is more suppressive than Ostarine at equivalent timeframes. Recovery occurred within 56 days of cessation in the trial.
LGD-4033 has Phase 1 safety data and Phase 2 data in hip fracture patients (VK5211). The Phase 1 trial by Basaria et al. is the most cited SARM trial in the literature.
Key trial: Basaria et al. (2013) — 76 healthy men, randomized, double-blind, placebo-controlled. Doses: 0.1, 0.3, and 1.0 mg/day for 21 days. This is the gold-standard Phase 1 SARM trial and the basis for most LGD-4033 research dose extrapolations.
LGD-4033 is stronger than Ostarine — which means the side effect profile is also more pronounced, especially at research doses above the clinical 1mg.
Third-party tested compounds from Swiss Chems — one of the most trusted research suppliers.
Affiliate link — supports MeetPeptide at no extra cost. All Swiss Chems products include third-party lab testing certificates.
Support supplements for SARM research protocols — liver protection, PCT support, and general health.
Affiliate links help support MeetPeptide at no extra cost to you.
Dosing schedules, interaction warnings, and cycle protocols for 50+ compounds — all in one place.
This page is for educational and informational purposes only. It is not medical advice. LGD-4033 (Ligandrol/VK5211) is NOT FDA approved for human use. It is a research chemical and is not a dietary supplement. The FDA has issued warning letters to companies marketing SARMs. All SARMs are banned by WADA in competitive sport. Always consult a qualified healthcare provider. MeetPeptide does not sell SARMs or endorse their use outside of legitimate research contexts.