Ligandrol (LGD-4033)
VK5211, Nonsteroidal SARM (Ligand / Viking Therapeutics)
Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- Not FDA approved; investigational
- WADA
- Prohibited at all times (S1.2 Other Anabolic Agents)
Reference only. Not medical advice.
What can go wrong
Dose-dependent suppression of testosterone, LH and FSH; reductions in HDL cholesterol and SHBG; reports of SARM-associated liver injury. Widely implicated in athlete adverse analytical findings, WADA reported dozens of LGD-4033 findings in a single year, with some cases traced to spiked or contaminated supplements not disclosed on the label.
This is something to take to a clinician. The Atlas can tell you what is known about ligandrol (lgd-4033) in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
LGD-4033 (ligandrol) is a nonsteroidal SARM discovered by Ligand Pharmaceuticals and later licensed to Viking Therapeutics (as VK5211) for post-hip-fracture recovery. A 21-day Phase I study in healthy young men (Basaria et al., 2013) showed dose-dependent lean-mass gain but also dose-dependent suppression of testosterone, SHBG, HDL and triglycerides. It is one of the most frequently detected SARMs in anti-doping cases, including several traced to contaminated dietary supplements.
The SARM behind a wave of athlete positives, including from spiked supplements.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
How it is supposed to work
Ligandrol is a high-affinity nonsteroidal AR agonist with tissue selectivity toward muscle and bone. Even at low milligram doses it suppresses the HPT axis, lowering LH, FSH and total/free testosterone in a dose-dependent way.
What the Phase I data actually showed
In Basaria et al. (2013), just 1 mg/day for 21 days in healthy men produced roughly a 50% drop in total testosterone and marked reductions in SHBG and HDL cholesterol, from a dose far below what bodybuilders use. Suppression reportedly recovered within weeks after stopping in that short trial, but this is a potent hormonal drug, not a benign supplement.
Safety in detail
LGD-4033 is an unapproved drug that measurably suppresses testosterone at sub-milligram doses. It is not a dietary supplement. Self-administration without medical oversight carries documented endocrine and hepatic risks, and it is a frequent source of anti-doping violations.
Replacement is not the same as a cycle
Trial doses were 0.1-1.0 mg/day. Bodybuilding regimens often use 5-10 mg/day or more, well above the doses that already halved testosterone in the Phase I study, amplifying HPTA suppression and lipid harm.
What it does to fertility
Suppresses LH/FSH and endogenous testosterone, which can impair sperm production. Short-trial suppression reversed after cessation, but no data exist at chronic consumer doses.
What has to be monitored
The bloodwork this needs, and the reason it belongs with a clinician rather than a website.
- Total/free testosterone, LH, FSH
- Lipid panel (HDL)
- Liver function tests
- Hematocrit
What people get wrong
Often saidLigandrol is basically approved because Viking studied it
ActuallyVK5211 was investigational for hip-fracture recovery; it has no FDA approval and is not a supplement.
Often saidA positive doping test means the athlete cheated
ActuallyMultiple LGD-4033 positives have been traced to contaminated or spiked supplements the athlete did not knowingly take.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
How we got here
LGD-4033 was discovered by Ligand Pharmaceuticals and entered clinical testing around 2009. In 2014 Viking Therapeutics licensed it as VK5211 and pursued recovery after hip-fracture surgery, reporting lean-mass gains in a Phase II study. Parallel to legitimate development, ligandrol became a fixture of the gray-market SARM trade and anti-doping caseload throughout the late 2010s.
- 2009Ligand begins clinical testing of LGD-4033
- 2013Basaria Phase I in healthy men published
- 2014Viking Therapeutics licenses it as VK5211
- 2016-2019Multiple high-profile athlete positives, some from contaminated supplements
At a glance
- Discoverer
- Ligand Pharmaceuticals
- Licensee
- Viking Therapeutics (VK5211)
- Phase I
- 76 healthy men, 21 days, 0.1-1.0 mg/day
- FDA approvals
- None
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Ligandrol (LGD-4033). A short entry is not a safe entry.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Basaria et al., Phase I in healthy young men (J Gerontol A Biol Sci Med Sci)2013
Dose-dependent lean-mass increase; dose-dependent suppression of testosterone, SHBG, HDL and triglycerides; well tolerated over 21 days
Detection of LGD-4033 and metabolites in athlete urine (Thevis et al.)2016
Established doping-control detection; long metabolite window
AIU (World Athletics) case, sprinter Carina Horn (contaminated supplement)2019
LGD-4033 detected in sealed and unsealed 'Mutant Madness' supplement; illustrates spiking/contamination