Metabolic Support
A UK research grouping of compounds studied in metabolism research: Retatrutide, Cardarine GW-501516, Ipamorelin and YK-11. Research use only, 18+.
Metabolic Support is a research-interest grouping of Free Muscle compounds that feature in the literature on metabolism, energy expenditure and body weight: Retatrutide, Cardarine (GW-501516) in 5 mg and 10 mg strengths, Ipamorelin and YK-11. All are supplied as capsules for laboratory research, every Free Muscle batch is assayed by Janoshik Analytical, and the certificate for your batch is available on request. The heading organises the catalogue. It is not a claim that any compound here affects the weight or metabolism of the person reading this page, and nothing here is a weight-loss product.
What this collection covers
- Retatrutide (LY3437943), a peptide agonist at the GIP, GLP-1 and glucagon receptors, in late-stage clinical trials and not approved in any country.
- Cardarine (GW-501516), a PPAR-delta agonist studied for lipid metabolism whose development ended after rodent tumour findings; 5 mg and 10 mg capsules, 60 per pack.
- Ipamorelin, a pentapeptide growth hormone secretagogue acting on the ghrelin receptor, with limited early clinical data; 60 capsules.
- YK-11, a steroidal compound reported in cell studies as a partial androgen receptor agonist with effects on myostatin-related signalling; 10 mg capsules, 60 per pack.
Other brands' metabolic research compounds, including SLU-PP-332 and 5-Amino-1MQ, are listed through Muscle Market.
What the published research reports
Retatrutide has the most substantial human data in this grouping. In a 48-week phase 2 trial of 338 adults with obesity, mean body weight fell by roughly 8 to 24 per cent across dose groups compared with about 2 per cent on placebo. Gastrointestinal adverse events were the most common finding and were dose-related, and phase 3 trials were still under way at the time of writing. Cardarine's human data is limited to short lipid studies, and its rodent safety programme reported tumours. Ipamorelin and YK-11 have little or no controlled human data. None of this is a claim about the products on this page.
Batch testing and certificates of analysis
A certificate of analysis states what an independent laboratory identified in a specific batch and the purity it measured. Every Free Muscle batch goes to Janoshik Analytical, and the batch number is printed on the pack. Email us the number and we will send the certificate for that batch. A document without a batch number is not a batch certificate. See how we test.
Legal status in the UK
None of these compounds is a licensed medicine (MHRA) or an authorised food supplement, and none may be sold for human consumption. They are supplied to adults for laboratory research. Retatrutide is an investigational drug with no marketing authorisation anywhere. Under the WADA list, GW-501516 is a prohibited metabolic modulator, ipamorelin a prohibited growth hormone secretagogue, YK-11 a prohibited anabolic agent, and retatrutide falls under non-approved substances.
Delivery and returns
Free Muscle is the trading name of FreeMuscle, a business registered in Andorra, with UK operations and dispatch in Scunthorpe. Every order ships free with UK tracking in plain packaging; EU delivery takes 3 to 7 working days. Orders placed before 2pm Monday to Friday are processed the same working day, and unopened items can be returned within 30 days. See shipping and guarantee. Customers must be 18 or over.
Related reading
- Retatrutide in the UK 2026: licensing status and trials
- SARMs vs Peptides: Choosing by Goal
- Price per milligram: how to compare SARMs and peptides
- What Is Janoshik Analytical? Third-Party Testing Explained
- Related collections: Cut, Peptides, SARMs
Research compounds sold by Free Muscle are supplied for laboratory research use only and are not for human consumption. They are not authorised as medicines by the MHRA, EMA or FDA, are not food supplements, and are sold only to adults aged 18 or over. Nothing on this page is medical or dosing advice.
References
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. PMID: 37366315.
Frequently asked questions
Are these weight-loss products?
No. Metabolic Support is a grouping of research compounds that appear in the literature on metabolism and body weight. None of them is a licensed medicine, a food supplement or a weight-loss product, and we make no claim that any of them affects the weight of a person. They are sold to adults for laboratory research only and are not for human consumption.
Is Retatrutide available on prescription in the UK?
No. Retatrutide (LY3437943) is an investigational drug in phase 3 clinical trials and has no marketing authorisation from the MHRA, EMA or FDA. It is not the same as the licensed GLP-1 medicines prescribed for obesity. Free Muscle lists it for laboratory research only. Anyone seeking treatment for weight should speak to a doctor.
What is the difference between Cardarine 5 mg and 10 mg?
Only the amount of GW-501516 per capsule; both packs hold 60 capsules and both are batch-tested by Janoshik Analytical. We do not advise on which strength to choose because the compound is sold for laboratory research, not for use in people. Compare total milligrams per pack and price per milligram if you are choosing between listings.
How do I check the batch certificate?
Every Free Muscle pack carries a printed batch number. Email it to us and we will send the Janoshik Analytical certificate for that batch, which records the compound identified and the purity measured. Match the batch number on the certificate to your pack. If the numbers do not match, the certificate does not describe your product.
Are these compounds banned in sport?
Yes. GW-501516 is listed by WADA as a metabolic modulator, ipamorelin as a growth hormone secretagogue, YK-11 as an anabolic agent, and retatrutide falls under non-approved substances. All are prohibited at all times. Accredited laboratories test for each of them, so athletes subject to testing should treat the whole collection as prohibited.