LGD-4033 (Ligandrol) UK: What the Research Says in 2026 | SARMs Store

Updated September 2026. LGD-4033 is sold by SARMs Store strictly as a research compound. Nothing on this page is medical advice or an instruction for human use.

LGD-4033, usually called Ligandrol and later coded VK5211 by Viking Therapeutics, is the second most clinically documented selective androgen receptor modulator after Ostarine. It has completed a phase I safety study in healthy men and a phase II trial in patients recovering from hip fracture, which puts it in a small group of SARMs with any human data at all. It is also widely misunderstood, because the potency figures quoted in forum posts rarely match the doses used in the published work. This guide sets out the research record, the reported side effects, the UK legal position in 2026 and how to judge a supplier.

What LGD-4033 is

Ligandrol is a non-steroidal SARM originally developed by Ligand Pharmaceuticals and later licensed to Viking Therapeutics. Like Ostarine it binds the androgen receptor and behaves as a tissue-selective agonist, producing anabolic activity in skeletal muscle and bone while showing much weaker activity in the prostate in preclinical models. It is orally available, and the phase I data put its half-life at roughly 24 to 36 hours, which is why the trials used once-daily administration.

LGD-4033 is not a steroid. It is not aromatised to oestrogen and not converted to dihydrotestosterone, so the oestrogenic and strongly androgenic effects associated with testosterone esters are absent from the published data. It is, however, considerably more potent per milligram than Ostarine, and the clinical doses that produced measurable changes in lean mass were an order of magnitude lower than the amounts commonly sold as research material. That gap is the single most useful thing to understand about the compound.

What the research found

Phase I, healthy young men (Basaria and colleagues, Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 2013). This is the foundational human study. Seventy-six healthy men aged 21 to 50 received placebo or 0.1 mg, 0.3 mg or 1 mg of LGD-4033 daily for 21 days. Lean body mass increased in a dose-dependent way, with the 1 mg group gaining roughly 1.2 kg over three weeks, a notable figure given the very short duration. Fat mass did not change significantly. The compound was described as well tolerated, with no serious adverse events and no clinically meaningful rise in liver enzymes. Total testosterone, free testosterone, sex hormone binding globulin, follicle stimulating hormone and HDL cholesterol all fell in a dose-dependent manner, and all returned towards baseline during follow-up. Exposure was linear and dose-proportional.

Phase II, hip fracture recovery (Viking Therapeutics VK5211, reported 2018). A twelve-week randomised trial in older patients recovering from hip fracture tested three daily doses against placebo. The headline result was an increase in lean body mass of approximately 4.8 per cent at the 2 mg dose relative to placebo. Functional endpoints were less clear cut, which mirrors what happened with Ostarine in phase III: SARMs have repeatedly added mass more reliably than they have improved measured performance.

Beyond those two studies the human record is thin. There is no long-term trial, no study in trained young men pursuing muscle gain, and no data at the higher amounts sold as research chemicals. Anything claiming specific results at 10 mg daily over eight weeks is anecdote, not evidence.

Doses used in the research

For reference only: the published human studies used 0.1 mg to 1 mg daily over 21 days in healthy men, and up to 2 mg daily over twelve weeks in the hip fracture programme. Research material is commonly supplied at 10 mg per capsule, which is five to a hundred times the studied range, and there is no controlled safety data at those levels. These figures describe the literature. They are not a recommendation, and SARMs Store does not sell LGD-4033 for human consumption.

Side effects reported

The phase I trial gives the clearest picture. Suppression of total and free testosterone was dose-dependent and consistent, along with reductions in sex hormone binding globulin and follicle stimulating hormone, and recovery occurred during follow-up. HDL cholesterol fell. Liver enzymes did not rise meaningfully at the trial doses.

Outside the trials the picture is different. Several published case reports and case series describe drug-induced liver injury in people who had taken bodybuilding products sold as LGD-4033, typically a cholestatic or mixed pattern of jaundice weeks into use. In a number of these the product was taken at doses far above anything studied, and in some cases analysis found undeclared or substituted ingredients. That combination, unstudied doses plus unverified material, is the recurring theme in SARM-related harm, and the strongest practical argument for buying only batch-tested product.

LGD-4033 compared with other compounds

Against Ostarine, LGD-4033 is markedly more potent per milligram and produced greater hormonal suppression at its studied doses, while Ostarine holds the larger human safety record and the only phase III data. RAD-140 is more potent again in animal models and carries a liver signal in its limited human exposure. YK-11 and S-23 have no human data, so no meaningful safety comparison is possible. Cardarine and Stenabolic are not SARMs and belong in a separate category despite being sold alongside.

Legal status in the UK, 2026

LGD-4033 is not a controlled substance under the Misuse of Drugs Act 1971 and is not scheduled as a Class C anabolic steroid. Under the Human Medicines Regulations 2012 it is treated as an unlicensed medicinal product if it is sold, advertised or supplied for human use, and the MHRA has enforced against UK sellers who cross that line. That is why legitimate UK suppliers list it strictly as a research compound and carry a research-only notice. In sport it is prohibited at all times by WADA as an “other anabolic agent” under section S1.2, and it has appeared in a number of anti-doping cases, including several attributed to contaminated supplements. UK Anti-Doping applies the same list.

How to check a supplier

Ask for the certificate of analysis for the specific batch on the bottle, not a generic example document. It should identify the compound by HPLC or LC-MS, state a purity percentage, and carry a batch number you can match to the label. The label itself should show compound name, milligrams per capsule, capsule count, batch number and a research-only notice. UK manufacturing shortens the supply chain and makes the testing claim verifiable. Dexterz Labs Ligandrol LGD-4033 is made in the UK at 10 mg per capsule, 90 capsules per bottle, and batch certificates of analysis are being published on the product page as testing is completed.

Frequently asked questions

Is LGD-4033 stronger than Ostarine? In animal models and on a per-milligram basis, yes, and the phase I data show greater hormonal suppression than Ostarine produced at its trial doses.

Does LGD-4033 suppress testosterone? Yes. The phase I study recorded dose-dependent falls in total testosterone, free testosterone, sex hormone binding globulin and follicle stimulating hormone, reversing after dosing stopped.

Is LGD-4033 liver toxic? The 21-day phase I trial found no meaningful rise in liver enzymes at up to 1 mg daily. Published case reports of liver injury involve products sold for bodybuilding use at far higher amounts, sometimes containing undeclared compounds.

What is VK5211? It is the development code Viking Therapeutics used for LGD-4033 in the hip fracture programme. Same molecule.

How long does LGD-4033 stay detectable? It and its metabolites are detectable in urine well beyond the dosing period, and it is routinely screened for in anti-doping testing.

Is LGD-4033 legal in the UK in 2026? It is legal to buy and possess as a research compound. Selling or advertising it for human consumption is not lawful, and it is banned in sport.