Important scope note: LGD-4033 is an investigational research compound, not an approved medicine, dietary supplement, or established treatment for muscle loss, osteoporosis, hypogonadism, or athletic performance. The dosing, cycling, post-cycle therapy, and stacking information below describes practices discussed in research and online drug-use communities for educational purposes; it is not a recommendation or a substitute for medical supervision. Human clinical evidence is limited, and the risks of unsupervised use include endocrine suppression, adverse lipid changes, liver injury, cardiovascular complications, psychiatric effects, infertility, and exposure to inaccurately labeled products.
What Is LGD-4033?
LGD-4033 is a synthetic, nonsteroidal selective androgen receptor modulator, or SARM. It was developed by Ligand Pharmaceuticals as an orally active androgen-receptor ligand intended to produce anabolic effects in skeletal muscle and bone with less stimulation of androgen-sensitive tissues than conventional anabolic-androgenic steroids. The compound was subsequently advanced by Viking Therapeutics under the development code VK5211, particularly for clinical investigation in people recovering from hip fracture. Unlike testosterone or many anabolic steroids, LGD-4033 was designed to exploit tissue-selective androgen-receptor pharmacology rather than to provide systemic androgen replacement.
LGD-4033 is frequently described as one of the most clinically studied SARMs, although its human evidence base remains small compared with approved medicines. A short randomized trial in healthy men demonstrated measurable increases in lean body mass at doses substantially below those commonly promoted online, together with suppression of serum testosterone and changes in high-density lipoprotein cholesterol. Viking Therapeutics also studied VK5211 in a Phase 2 hip-fracture recovery program. Preclinical work suggested strong anabolic activity in muscle and bone, while oral administration and relatively high oral bioavailability made the compound attractive for development. These favorable pharmacologic properties do not establish safety or efficacy for bodybuilding, sports performance, or self-treatment.
The name Ligandrol is commonly used in supplement, bodybuilding, and research-chemical markets, but commercial identity does not guarantee chemical identity. Products labeled LGD-4033 may contain a different SARM, another active drug, an incorrect concentration, or no meaningful amount of the stated compound. "Research use only" labeling does not make human consumption lawful or safe. In sport, LGD-4033 is prohibited by the World Anti-Doping Agency at all times.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral selective androgen receptor modulator, in healthy young men.
Basaria, S., Collins, L., Dillon, E. L., et al., 2013, The Journals of Gerontology Series A - Selective androgen receptor modulators: clinical applications and emerging therapeutic potential.
Narayanan, R., Coss, C. C., Yepuru, M., et al., 2018, Endocrine Reviews - Selective androgen receptor modulators: current status and future perspectives.
Mohan, S., and Narayanan, R., 2018, Steroids - Chemical analyses of commonly available selective androgen receptor modulators.
Van Wagoner, R. M., Eichner, A., and Bhasin, S., 2017, JAMA - Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement.
Pope, H. G., Wood, R. I., Rogol, A., et al., 2014, The Lancet