LGD-4033 (Ligandrol) — Research Literature Summary
Class: SARM • Page type: research-literature reference • Updated 2026-04-23
Regulatory notice — research reference only
LGD-4033 is an investigational SARM that has not been approved for human use by any regulatory authority. The U.S. FDA and DOJ have explicitly enforced against sale of SARMs for human consumption. This page summarizes published preclinical and Phase I research literature only.
Published research summary
- LGD-4033 (ligandrol, VK5211) is an orally bioavailable, nonsteroidal selective androgen receptor modulator developed by Ligand Pharmaceuticals and later investigated by Viking Therapeutics.
- In the published Phase I study (Basaria et al., J Gerontol A Biol Sci Med Sci 2013), 21 days of oral LGD-4033 at 0.1, 0.3, or 1.0 mg/day produced dose-dependent increases in lean body mass (~1 kg at 1.0 mg) without significant change in fat mass in 76 healthy young men.
- A subsequent Phase II study in postmenopausal women (Papanicolaou 2013) evaluated 0.1-1.0 mg/day for 12 weeks; results were mixed and development for that indication did not advance.
- Suppression of testosterone, LH, FSH, HDL, and SHBG was dose-dependent in both trials. The long-term safety profile at doses above 1 mg/day in humans has not been established in peer-reviewed literature.
- LGD-4033 is prohibited at all times (in- and out-of-competition) on the WADA Prohibited List (Section S1.2 - Other Anabolic Agents).
Why this page does not publish a consumer “cycle” schedule
Consumer 'cycle' or 'PCT' protocols are not a research-literature construct. Published clinical trials studied fixed 21-day or 12-week dosing at defined single doses under physician supervision. Any guidance beyond this - stacking, post-cycle therapy with Nolvadex/Enclomiphene, recommended bulk/cut cycles - is not reflected in the peer-reviewed record.
Peer-reviewed citations
Consulting a healthcare provider: This page is a reference for published research. If you are considering any health decision, consult a licensed healthcare provider. Path to Peptides does not provide medical advice.
Clinical trials showed 2-3 lbs of lean mass gain over 21 days at 1mg/day. At research doses of 5-10mg, users typically report 4-8 lbs of lean mass over an 8-12 week cycle, though some is water retention that subsides post-cycle.
Frequently Asked Questions
The standard research dose is 5-10mg taken orally once daily. Beginners typically start at 5mg for 8 weeks. Due to its long half-life of 24-36 hours, once-daily dosing maintains stable blood levels.
Yes. LGD-4033 suppresses natural testosterone production in a dose-dependent manner. A PCT protocol using Enclomiphene (12.5-25mg/day) or Nolvadex (20mg/day for 4 weeks) is recommended after cycles of 8 weeks or longer.
Clinical trials showed 2-3 lbs of lean mass gain over 21 days at 1mg/day. At research doses of 5-10mg, users typically report 4-8 lbs of lean mass over an 8-12 week cycle, though some is water retention that subsides post-cycle.