RESEARCH CARDARINE 5MG

Cardarine 5 mg in the UK: buying, legal status and what to check

Three strands of UK law decide how GW-501516 can be sold. It is not a controlled drug under the Misuse of Drugs Act 1971. It has no marketing authorisation, and the MHRA regulates any product presented as treating or preventing disease as a medicine, so it cannot carry medicinal claims. It has no food or novel food authorisation, so it cannot be sold as a supplement. What remains is supply as a research chemical to adults aged 18 or over, without health claims or instructions for human use, which is how FreeMuscle LTD of Scunthorpe sells it.

Searches for "cardarine uk reviews" assume buyers can vouch for contents; they cannot. Of 44 products bought online as SARMs and analysed with anti-doping methods, only 41% contained the labelled amount, 9% contained no active compound, a quarter held unlisted substances, and GW-501516 was among the unapproved drugs found (Van Wagoner 2017). Only a certificate for the batch catches that.

This bottle holds 60 capsules of 5 mg, 300 mg of GW-501516 in total; its label carries a batch number, and the Janoshik Analytical certificate for that batch is available on request. Orders placed before 2pm Monday to Friday are processed the same working day, with free tracked UK delivery in plain packaging and 30-day returns on unopened items (see shipping and our guarantee).

Capsules compared with other forms

A capsule keeps GW-501516 as a solid, and the solid form matters. Recrystallisation from a range of solvents produced a new polymorph of cardarine (a different crystal packing of the same molecule), a cocrystal, and mono-oxidised and di-oxidised versions of the molecule (Turza 2025). A liquid avoids the polymorph question, but its label gives a concentration per millilitre rather than a fixed quantity per unit.

At 5 mg the active compound is a small share of each capsule's contents and is typically blended with an inert filler, so the evenness of that blend decides whether the first and sixtieth capsules match. That is why the figure to look for is content per capsule, not only raw-powder purity. No form of GW-501516 has a completed human efficacy trial, so the choice here is about what can be measured, not about any effect.

Cardarine compared with SLU-PP-332

Both are described in the literature as exercise mimetics acting on nuclear receptors that govern energy metabolism in muscle, but the receptors differ. GW-501516 is a selective agonist of PPAR-delta, a sensor of dietary fatty acids. SLU-PP-332 is a synthetic pan-agonist of the oestrogen-related receptors ERRα, ERRβ and ERRγ, most potent at ERRα; despite the name, these orphan receptors do not respond to oestrogen.

GW-501516 reached small human trials before its programme stopped. SLU-PP-332 has cell and mouse data only: in mice it increased type IIa oxidative muscle fibres and exercise endurance, an effect that depended on ERRα (Billon 2023). We found no published study giving it to people, so its effects and risks in humans are unknown.

In the UK and EU both lack any medicine licence or food authorisation and are sold for research only. WADA names GW-501516 as a metabolic modulator in section S4; SLU-PP-332, never approved for human use, falls under the S0 ban on non-approved substances unless a more specific section covers it. See the SLU-PP-332 range.

Reading the certificate of analysis for this 5 mg batch

Start by confirming the molecule. The name, formula or mass on the certificate should agree with these PubChem identifiers.

A mass-spectrometry identity result should be consistent with 453.5; the recorded ion usually sits one unit either side, depending on instrument mode. The oxidised forms carry one or two extra oxygen atoms (Turza 2025), placing them near 469.5 and 485.5, and would normally elute separately on HPLC, so oxidation lowers the purity figure rather than hiding inside it.

Then read the content result against 5 mg. Small absolute errors weigh more at low strength: half a milligram is 10% of a 5 mg capsule but 5% of a 10 mg one. Finally, match the batch number on the certificate to your label. The certificate is sent by email on request: quote the batch number and product name via our contact page; the process is explained on lab tests.

Detection, sport and testing

GW-501516 is prohibited at all times under WADA section S4, hormone and metabolic modulators. In a 2021 hospital case the compound was measured in blood and hair but the parent drug was absent from urine, so urine testing has to target breakdown products; hair analysis indicated repeated exposure over about the previous two months (Kintz 2021). Anti-doping rules also apply strict liability: presence is the violation and the source affects only the sanction. In one of two findings investigated in 2024, the evidence supported transfer to a female athlete through unprotected intercourse (Breuer 2024).

Mislabelled products can cause the same kind of unwitting positive, since GW-501516 has turned up in products sold under other names (Van Wagoner 2017). None of the papers cited here reports how long it remains detectable after exposure, so no window is given. Athletes in tested sport should regard it as banned in every circumstance.

Storage, stability and handling

The weak point of GW-501516 is its sulfur link. Thioethers oxidise to sulfoxides and then sulfones, and both oxidised forms of cardarine have been isolated (Turza 2025). Oxygen, heat and light generally speed such reactions, so keep the lid closed between uses, store the bottle in a cool, dark, dry cupboard and do not decant capsules into other containers or open dishes. If it is refrigerated, let the closed bottle reach room temperature before opening so condensation does not form. Write the opening date beside the batch number, set aside capsules that turn sticky or discoloured, keep it out of reach of children and follow laboratory practice for handling and disposal.

What the published research reports

GW-501516 came out of a GlaxoSmithKline programme as a potent, subtype-selective PPAR-delta agonist. In obese, insulin-resistant rhesus monkeys it raised HDL cholesterol and lowered small dense LDL, fasting triglycerides and fasting insulin (Oliver 2001). In a randomised, double-blind crossover trial in 13 men with central obesity and abnormal blood lipids, with six-week periods on GW-501516 and on placebo, triglycerides and apolipoprotein B fell and HDL cholesterol rose; the authors attributed the fall in VLDL mainly to faster removal of VLDL particles by the liver (Ooi 2011). The trial was small and short and measured lipoprotein turnover, not clinical outcomes.

The adverse findings are serious. Clinical development was halted after long-term carcinogenicity studies in rodents found tumours, and the compound has never been approved as a medicine anywhere. In ApcMin mice, which are prone to intestinal polyps, GW-501516 increased polyp number and size, with a fivefold rise in polyps larger than 2 mm (Gupta 2004). A 2021 case report described a man hospitalised with severe liver-cell injury and massive rhabdomyolysis after reportedly taking GW-501516 with ostarine for several days; he had fully recovered six weeks after admission, and one case involving two compounds cannot assign cause (Kintz 2021). These are findings in study animals and volunteers, not claims about the capsules sold here.

Related compounds and reading

• Free Muscle Cardarine 10 mg, the same molecule at twice the fill, and every cardarine listing we stock.
• SLU-PP-332 and 5-Amino-1MQ, covered in SLU-PP-332 and 5-Amino-1MQ: what the mouse data show.
• SR9009 (Stenabolic) and the wider Metabolic Support range.
• Cardarine (GW-501516): why development stopped
• Choosing a SARMs or peptide supplier in the UK and What is Janoshik Analytical?

Glossary

• Nuclear receptor: a protein that, once activated, binds DNA and changes which genes are read.
• ERR: oestrogen-related receptor, the orphan receptor family targeted by SLU-PP-332.
• Exercise mimetic: a research label for compounds that switch on parts of the training gene programme; not evidence of effects in people.
• Thioether: a sulfur atom bonded between two carbons, which oxidises to a sulfoxide and then a sulfone.
• Polymorph: one of several crystal packings of the same molecule.
• Content uniformity: how closely the amount of active compound matches from capsule to capsule.
• InChIKey: a fixed-length structure code used to match a compound across databases.
• Rhabdomyolysis: breakdown of skeletal muscle that releases enzymes such as creatine kinase into the blood.
• Strict liability: the anti-doping rule that presence of a prohibited substance is itself a violation.

Cardarine (GW-501516) 5 mg is supplied by FreeMuscle LTD for laboratory research use only, to adults aged 18 and over. It is not a medicine, has not been evaluated by the MHRA, EMA or FDA, is not a food supplement and is not for human consumption. WADA prohibits it in sport. This page contains no medical advice and no guidance on human use.

References

• Oliver WR Jr, et al. A selective peroxisome proliferator-activated receptor delta agonist promotes reverse cholesterol transport. Proc Natl Acad Sci U S A. 2001;98(9):5306-5311. PMID: 11309497.
• Ooi EM, et al. Mechanism of action of a peroxisome proliferator-activated receptor (PPAR)-delta agonist on lipoprotein metabolism in dyslipidemic subjects with central obesity. J Clin Endocrinol Metab. 2011;96(10):E1568-E1576. PMID: 21816786.
• Gupta RA, et al. Activation of nuclear hormone receptor peroxisome proliferator-activated receptor-delta accelerates intestinal adenoma growth. Nat Med. 2004;10(3):245-247. PMID: 14758356.
• Kintz P, et al. Peroxisome Proliferator-Activated Receptor Delta Agonist (PPAR-δ) and Selective Androgen Receptor Modulator (SARM) Abuse: Clinical, Analytical and Biological Data in a Case Involving a Poisonous Combination of GW1516 (Cardarine) and MK2866 (Ostarine). Toxics. 2021;9(10):251. PMID: 34678947.
• 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.
• Breuer J, et al. Complementary information concerning the suspected interindividual transmission of GW1516, a substance prohibited in sport, through intimate contact: a case report. Forensic Toxicol. 2024;42(2):248-254. PMID: 38704758.
• Turza A, et al. Novel Solid Forms of Cardarine/GW501516 and Their Characterization by X-Ray Diffraction, Thermal, Computational, FTIR, and UV Analysis. Pharmaceutics. 2025;17(2):152. PMID: 40006519.
• Billon C, et al. Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity. ACS Chem Biol. 2023;18(4):756-771. PMID: 36988910.