People searching "LGD 4033", "ligandrol side effects" or "does ligandrol work" are usually trying to separate a small body of genuine clinical research from a much larger volume of forum anecdote. LGD-4033 is unusual among compounds sold as SARMs in that it has a proper placebo-controlled trial in healthy young men, published in a peer-reviewed journal, with hormone, lipid and body composition data. That trial is short, small and low-dose, and it is the whole of the healthy-volunteer literature. This guide explains what it found, what has been reported since, and where LGD-4033 stands under UK law, EU law, US law and the WADA code. It contains no guidance on use. LGD-4033 is sold on this site for laboratory research only.
What is LGD-4033?
LGD-4033 is a non-steroidal, orally active selective androgen receptor modulator discovered by Ligand Pharmaceuticals, from which the "LGD" prefix comes. It was later licensed to Viking Therapeutics under the code VK5211, and the name "ligandrol" is an informal one used by sellers rather than a registered trade name. Chemically it is a pyrrolidine-substituted benzonitrile bearing a trifluoromethyl group; it has no steroid ring system.
It binds the androgen receptor with high affinity and selectivity, and was developed with the aim of producing anabolic effects in muscle and bone while sparing the prostate (Basaria et al., 2013). The licensee announced a phase 2 study in older adults recovering from hip fracture, but its results have not appeared in a peer-reviewed journal that we can cite, no phase 3 programme has followed, no marketing authorisation has been granted anywhere, and LGD-4033 remains an investigational compound with no approved use. Our overview What Are SARMs? covers how it fits into the wider class.
Mechanism of action
LGD-4033 is an androgen receptor agonist. In the receptor-bound state it recruits co-activators and drives the transcription of androgen-responsive genes. The tissue-selective profile claimed for the SARM class comes from differences in how the receptor-ligand complex behaves in different cell types, not from the compound avoiding those tissues altogether. Two consequences follow, both visible in the human data.
- Feedback suppression. Any androgen receptor agonist that reaches the hypothalamus and pituitary reduces the body's own gonadotrophin output. In the 21-day trial, total testosterone, sex hormone-binding globulin, HDL cholesterol and triglycerides all fell in a dose-dependent way, and follicle-stimulating hormone and free testosterone fell at the highest dose (Basaria et al., 2013).
- Long half-life and accumulation. The same study reported a long elimination half-life and dose-proportional accumulation on repeated administration, meaning that blood levels build over days rather than clearing overnight.
What the research reports
The 21-day healthy volunteer trial
Basaria and colleagues randomised 76 healthy men aged 21 to 50 to placebo or one of three low doses of LGD-4033 for 21 days, then followed them for a further five weeks (Basaria et al., 2013). The reported findings were:
- No drug-related serious adverse events, and a similar frequency of adverse events in the active and placebo groups. The authors described the compound as well tolerated over the three weeks.
- No significant change in haemoglobin, prostate-specific antigen, liver transaminases (AST and ALT) or QT interval at any dose.
- Dose-dependent suppression of total testosterone, SHBG, HDL cholesterol and triglycerides. FSH and free testosterone were suppressed at the top dose.
- Lean body mass increased in a dose-dependent manner; fat mass did not change significantly.
- Hormone and lipid values returned to baseline after the compound was stopped.
The limitations are as important as the results. Twenty-one days is far too short to detect slow-developing harms. The doses studied were low. The participants were young, healthy, medically screened men. The reassuring liver and PSA findings apply to that setting only, and the authors themselves called for longer randomised trials in defined patient groups.
Case reports and adverse event analyses
Since 2020, the picture from outside clinical trials has been less reassuring. A 32-year-old man developed severe drug-induced liver injury after using ligandrol, confirmed by liver biopsy showing cholestatic hepatitis with mild fibrosis (Barbara et al., 2020a). The same group reported a 52-year-old who developed liver injury after products containing RAD-140 and a combination of RAD-140 and LGD-4033 (Barbara et al., 2020b); in that case liver enzymes took about three months to return to normal after both products were stopped. A 2024 review of suspected SARM adverse events found 20 published reports since 2020, most involving cholestatic or hepatocellular liver injury and jaundice, and stressed that little is known about the dose and purity of the products involved (Leciejewska et al., 2024). An Australian case series of 23 liver injury patients linked to anabolic steroids, SARMs and bodybuilding supplements reported a median onset of 58 days after starting, hospital admission in most, a median of 175 days for liver tests to normalise, and one liver transplant (Nash et al., 2024).
The gap between the trial and the case reports is explained partly by dose and duration, and partly by product quality. When 44 products sold online as SARMs were analysed, only 52 per cent contained a SARM at all, LGD-4033 being one of the three actually found, and only 41 per cent contained the labelled amount (Van Wagoner et al., 2017). A person harmed by a product labelled "LGD-4033" may have taken a different compound, a much larger dose than they believed, or both.
Survey data
A cross-sectional survey of 343 self-reported SARM users recruited through Reddit forums found that more than 90 per cent bought online without consulting a physician, and more than half reported side effects including mood swings, reduced testicular size and acne (Efimenko et al., 2022). Self-report surveys cannot verify what was taken, but they capture the experience of the population actually using these products.
None of this is a claim about any product sold on this site. Products here are for laboratory research and have not been tested for any effect in people.
Regulatory status
| Jurisdiction or body | Status of LGD-4033 |
|---|---|
| UK (MHRA) | Not a licensed medicine; not an authorised food; not a controlled drug |
| European Union | No marketing authorisation; no novel food authorisation |
| United States (FDA) | Not approved; FDA warnings about SARMs in consumer products |
| WADA | Prohibited at all times, class S1.2 |
United Kingdom
LGD-4033 is not a licensed medicine and has never been assessed by the MHRA. It is not an authorised food supplement or novel food, so it cannot lawfully be sold or marketed for consumption. It is not a controlled drug under the Misuse of Drugs Act 1971. UK suppliers sell it as a research chemical to adults aged 18 or over for laboratory use, and that is the only basis on which Free Muscle offers it. The brands stocked are listed in the LGD-4033 collection.
European Union
There is no EU marketing authorisation and no novel food authorisation, and the EMA has not approved any SARM (Leciejewska et al., 2024). Buyers outside the UK are responsible for the import rules of their own country.
United States
The FDA has approved no SARM and has issued public warnings about SARMs in bodybuilding products, citing liver toxicity and cardiovascular risk. It has also issued warning letters to companies marketing SARMs as dietary supplements.
WADA
LGD-4033 is named on the World Anti-Doping Agency Prohibited List under S1.2, other anabolic agents, and is prohibited at all times. Anti-doping laboratories detect it and its metabolites in urine by mass spectrometry; a 2017 paper from a WADA-accredited laboratory describes the detection of LGD-4033 and its metabolites in athlete urine samples (Cox and Eichner, 2017). Because the compound has a long half-life and accumulates, detection windows are likely to be long, but we have not found a verified published figure and so state: detectable, window not established. Athletes who have returned positive tests for ligandrol have in some cases attributed the finding to a contaminated supplement, which under the strict liability principle does not by itself remove responsibility.
Common questions
Is LGD-4033 legal in the UK?
It is not a controlled drug, so possessing it is not an offence under the Misuse of Drugs Act 1971, and adults may buy it for laboratory research. It is not a licensed medicine or an authorised food, so it cannot lawfully be sold or promoted for human consumption, and it is prohibited in sport at all times.
LGD-4033 vs RAD-140
Both are non-steroidal androgen receptor agonists. LGD-4033 has a placebo-controlled trial in healthy men; RAD-140's published human data come mainly from an early-phase trial in women with advanced breast cancer, in which raised liver enzymes were reported. Both have liver injury case reports. Both are WADA-prohibited and unlicensed. The RAD-140 collection and our RAD-140 research guide cover the other compound.
Ligandrol vs ostarine
Ostarine (enobosarm) has by far the larger clinical programme, including phase 2 trials and phase 3 trials in cancer-related muscle wasting. LGD-4033's human data are a single short trial. Both are prohibited in sport and unlicensed. See the Ostarine collection and our Ostarine research guide.
LGD-4033 dosage, cycle, before and after, results
We do not publish dosing, cycle or outcome guidance for LGD-4033 and we make no claims about what it does in people. The only controlled human data are the 21-day trial summarised above. Products here are sold for research.
How long does ligandrol take to kick in, and does it work?
These are questions about use in people, which we do not advise on. The published trial measured body composition after 21 days at low doses in a controlled setting; that is the extent of the evidence, and it is not a basis for any claim about products.
Is ligandrol a SARM or a peptide?
It is a SARM. It is a small synthetic molecule, not a chain of amino acids. It is unrelated to peptides such as BPC-157 or ipamorelin. Our article SARMs vs Peptides explains the distinction.
LGD-4033 half-life
The trial authors reported a long elimination half-life with dose-proportional accumulation on repeated administration, without giving a single headline figure in the abstract. Specific numbers circulate online, but we have not verified one against a peer-reviewed source, so we do not quote one here.
What do Reddit and forum reports say about ligandrol?
Forum posts are anecdotes about products of unknown content. The closest thing to systematic data is the Reddit-based survey by Efimenko and colleagues described above, in which more than half of respondents reported side effects. Given that under half of the online SARM products tested by Van Wagoner and colleagues matched their labels, forum reports cannot tell you what compound, or how much of it, was involved.
LGD-4033 for sale in the UK: what to compare
We do not quote prices in guides because they change. When comparing listings for research, compare the stated strength per capsule, the number of capsules, the total milligrams per pack and whether a certificate of analysis for that specific batch is available. The LGD-4033 collection lists each brand stocked, and our price per milligram guide explains the arithmetic.
How to verify a batch
Given the mislabelling documented by Van Wagoner and colleagues, a certificate of analysis for the exact batch is the minimum standard. Look for:
- Identity: an HPLC or LC-MS result confirming the compound is LGD-4033 against a reference standard.
- Purity: a percentage figure. Purity without identity is meaningless, because a pure sample of the wrong compound still passes.
- Assay against label: the measured content per capsule compared with the stated strength.
- Batch number and test date that match the pack in your hand, and the name of an independent laboratory.
Every Free Muscle-brand batch is assayed by Janoshik Analytical, and the certificate for your batch is sent on request by email. For other brands sold on Muscle Market, a certificate is shown only where the manufacturer has supplied one for the batch held. A brand-wide PDF with no batch number is marketing, not evidence. See How to Read a Certificate of Analysis, What Is Janoshik Analytical? and the lab tests page.
Related reading
- LGD-4033 (Ligandrol) collection: every brand stocked, compared on strength per capsule and batch testing.
- SARMs collection
- RAD-140 (Testolone) and Ostarine (MK-2866) collections.
- RAD-140 (Testolone): what the research says and Ostarine (MK-2866) research guide.
- Price per milligram: the honest way to compare listings.
- SARMs Explained
LGD-4033 is sold for laboratory research use only. It is not a licensed medicine, has not been evaluated by the MHRA, EMA or FDA, is not a food supplement and is not for human consumption. Products are supplied to adults aged 18 and over. Nothing on this page is medical advice or dosing, cycle or usage guidance. Summaries of published studies describe what researchers reported in their study populations and are not claims about any product.
References
- Basaria S, et al. The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral, selective androgen receptor modulator, in healthy young men. J Gerontol A Biol Sci Med Sci. 2013;68(1):87-95. PMID: 22459616.
- Barbara M, et al. Ligandrol (LGD-4033)-Induced Liver Injury. ACG Case Rep J. 2020;7(6):e00370. PMID: 32637435.
- Barbara M, et al. Drug-Induced Liver Injury Associated With Alpha Bolic (RAD-140) and Alpha Elite (RAD-140 and LGD-4033). ACG Case Rep J. 2020;7(6):e00409. PMID: 33062783.
- Leciejewska N, et al. Selective androgen receptor modulator use and related adverse events including drug-induced liver injury: Analysis of suspected cases. Eur J Clin Pharmacol. 2024;80(2):185-202. PMID: 38059982.
- Nash E, et al. Drug-induced liver injury from selective androgen receptor modulators, anabolic-androgenic steroids and bodybuilding supplements in Australia. Aliment Pharmacol Ther. 2024;59(8):953-961. PMID: 38372012.
- Van Wagoner RM, et al. Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet. JAMA. 2017;318(20):2004-2010. PMID: 29183075.
- Efimenko IV, et al. Adverse effects and potential benefits among selective androgen receptor modulators users: a cross-sectional survey. Int J Impot Res. 2022;34(8):757-761. PMID: 34471228.
- Cox HD, Eichner D. Detection of LGD-4033 and its metabolites in athlete urine samples. Drug Test Anal. 2017;9(1):127-134. PMID: 27168428.