IGF-1 LR3 UK orders: reading the certificate of analysis first

This IGF-1 LR3 UK guide explains what to check on a batch Certificate of Analysis before ordering: the seven lines to read, the red flags, and how to request the COA for your batch. It also covers where the compound stands in law and how ordering from Free Muscle works. It draws on regulators' own pages, primary legislation and the published research. It is general information, not legal advice and not medical advice. Listings (laboratory research only, 18+): IGF-1 LR3 capsules.

Key takeaways

• IGF-1 LR3 (also written Long R3 IGF-1, for long arginine-3 insulin-like growth factor-1) is a laboratory analogue of IGF-1, a natural growth factor. It is not the prescription medicine mecasermin (Increlex).
• The World Anti-Doping Agency (WADA) 2026 Prohibited List names IGF-1 "and its analogues" under section S2, prohibited at all times. LR3 is an analogue, so it is understood to fall under that entry.
• Regulation 46 of the Human Medicines Regulations 2012 says a person may not sell or supply an unauthorised medicinal product. According to the MHRA guidance linked here, whether a product is a medicine depends on how it is presented and what it does, and a label alone is understood not to settle that. This is general information, not legal advice.
• None of the studies included in this guide's records tested IGF-1 LR3 in people. The published work is in cells, embryos and animals, and the species disagree with each other.
• A batch-specific Certificate of Analysis (COA) from a named independent laboratory is the document that reports testing for a given batch. Free Muscle sends the COA for a batch on request.
• 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.

Is IGF-1 LR3 legal in the UK?

There is no single sentence that answers this fairly, because the answer depends on how a product is presented and what it does. What can be stated reliably comes from the legislation and the regulators' own pages. This is general information, not legal advice.

The Human Medicines Regulations 2012

Regulation 46 says that a person may not sell or supply, or offer to sell or supply, an unauthorised medicinal product (legislation.gov.uk, regulation 46). Regulation 220 adds that a medicinal product that is not subject to general sale may not be sold or supplied except by a retail pharmacy business at a registered pharmacy under pharmacist supervision (legislation.gov.uk, regulation 220).

These rules apply to medicinal products. So the working question is what counts as one.

What the MHRA says counts as a medicine

According to the Medicines and Healthcare products Regulatory Agency (MHRA) guidance on borderline products, a medicinal product is any substance presented as having properties of preventing or treating disease in human beings, or one that may be used by or administered to humans to restore, correct or modify a physiological function through a pharmacological, immunological or metabolic action, or may be used for making a medical diagnosis. The guidance describes the MHRA deciding on presentation and function.

The MHRA page linked here does not mention the phrase "research use only". It follows that a label alone is understood not to settle whether something is a medicine. That is our reading of the guidance, and it is why this article does not tell you that any product is or is not lawful to buy.

What the MHRA has said about enforcement

In a May 2021 press release, the MHRA stated that medicines without a marketing authorisation cannot be guaranteed to meet the quality and safety standards required in the UK, and called selling unlicensed or prescription medicines a serious criminal offence. The case concerned a personal trainer sentenced to 31 months for selling steroids and other medicines online. It did not concern IGF-1 LR3 or any research compound; it is cited only for the MHRA's stated position on unlicensed medicines.

The prescription-only relative

The European Medicines Agency (EMA) describes Increlex (mecasermin, recombinant human IGF-1) as an injection for long-term treatment of patients aged 2 to 18 years with severe primary IGF-1 deficiency, designated an orphan medicine in 2006 and obtainable only with a prescription. IGF-1 LR3 is a different molecule and is not Increlex.

Anti-doping status

The WADA 2026 Prohibited List, in effect from 1 January 2026, lists "Insulin-like growth factor 1 (IGF-1, mecasermin) and its analogues" in section S2, which is prohibited at all times, in and out of competition, and all substances in that class are non-Specified Substances (WADA 2026 Prohibited List). The list does not name LR3 specifically. Its inclusion rests on the words "and its analogues".

UK Anti-Doping explains that WADA manages the list, updates it every year and brings it into force on 1 January. It also notes that if a substance prohibited in-competition is found in your system you may face a ban regardless of when it was taken. The UKAD page does not itself name IGF-1. Anyone subject to anti-doping rules should check with UK Anti-Doping directly.

The position for the other compounds we stock, side by side: Are SARMs legal in the UK? 2026 guide

What "research use only" means, and what it does not

At Free Muscle, "research use only" means that research compounds are sold for laboratory research use only, to customers aged 18 or over, and are not medicines or food supplements and not for human consumption.

It is worth being plain about the limits of the label:

• It is not the MHRA's test. According to the MHRA guidance linked above, the question of whether a product is a medicine turns on presentation and function. The page does not mention the phrase "research use only", so a label alone is understood not to settle it. This is general information, not legal advice.
• It is not a quality statement. Identity and purity are matters for analytical testing, which is the subject of the COA sections below.
• It does not make anti-doping rules irrelevant. The WADA entry is prohibited at all times, in and out of competition; a label does not change what the Prohibited List names.

What researchers and regulators say

This section is the "what others say" part of the guide. It reports only published research and official bodies. Anecdotal reports from online forums are not evidence and are not used here. Every finding below describes what happened to the named cells, animals or patients in that study. None of it can be assumed to apply to people, or to an oral capsule.

The human evidence is thin

A 2026 narrative review in Frontiers in Endocrinology of GH-IGF-1 axis research-compound peptides, which includes IGF-1 LR3 among the agents covered, ranked peptides into evidence tiers from regulatory-grade randomised trial data to a complete absence of human studies (Dominikowski et al., 2026). Across the whole group of peptides reviewed (not LR3 alone), the authors described reported adverse effects across endocrine and metabolic disturbances (including prolactin and cortisol elevations, appetite changes and dysglycaemia), fluid retention, muscle and joint pain and injection-site reactions. They also flagged biologically plausible but unproven mitogenic concerns, meaning concerns about stimulating cell growth, and noted there is no regulatory approval for physique or performance purposes.

None of the studies included in this guide's records tested IGF-1 LR3 in people. The clinical studies cited here concern recombinant human IGF-1 products such as mecasermin (described by Rosenbloom as injectable) or mecasermin rinfabate (given intravenously in the Cochrane review), and are not evidence about LR3. The pooled epidemiological analysis cited below measured natural blood levels of IGF-1.

Animal studies point in different directions

The studies below differ in species, route and design, and they did not all agree.

• In a 1993 study of 160 g rats made diabetic with streptozotocin, with peptides given by mini-osmotic pump, IGF-1 and two variants (one of them LR3) restored growth in those rats, the variants being 2.5 to 3 times more potent than IGF-1 at doing so, and all three peptides raised muscle protein-synthesis rates and RNA levels by up to 50 per cent. In the same rats the peptides did not reduce glucose in the urine the way insulin did, and the authors concluded that other insulin-dependent metabolic processes were not restored (Tomas et al., 1993).
• In female guinea pigs of 350 g infused with the peptide, LR3 increased the relative weight of the adrenals, gut, kidneys and spleen, yet overall growth was not stimulated, and plasma IGF-1, IGF-2 and binding-protein concentrations fell (Conlon et al., 1995).
• In finishing pigs given an infusion, LR3 lowered weight gain, food intake and plasma insulin, IGF-1 and IGFBP-3, and mean plasma growth hormone fell by 23 per cent and the area under the growth hormone peaks by 60 per cent in those pigs. The authors noted that analogues which stimulate growth in the rat inhibit it in the pig (Dunaiski et al., 1997).
• In beef heifers on restricted feeding, an intravenous infusion tended to conserve whole-body and muscle protein, but plasma amino acids and glucose fell markedly and the animals' own plasma IGF-1 dropped sharply (Hill et al., 1999).

In cell and embryo work, LR3 was added to bovine embryo cultures (Prelle et al., 2001), where its affinity for IGF-binding proteins was at least three orders of magnitude lower than that of IGF-1, and a chicken LR3 analogue was tested on turkey muscle cells, where it was less active than chicken IGF-1 (Pesall et al., 2001). These were in vitro systems and say nothing directly about whole animals or people.

Adverse findings reported in the literature

In rats carrying a mammary tumour, infused IGFs increased tumour growth, "especially by LR3-IGF-I", although the peptides had not promoted that tumour in cell culture. The peptides also lowered food intake, insulin and glucose, and LR3 had no positive effect on carcass protein (Tomas et al., 1994).

For human epidemiology, a pooled analysis of 17 prospective and two cross-sectional studies, with up to 10,554 prostate cancer cases and 13,618 controls, found an odds ratio of 1.29 (95% CI 1.16 to 1.43) for the highest versus lowest fifth of circulating IGF-1 in the prospective studies (Travis et al., 2016). That measured natural circulating levels of IGF-1 in men, not LR3. A review of IGF-1 and the gut separately described evidence suggestive of a role for IGF-I in certain cancers, while noting that causality remains unproven (Howarth, 2003).

For mecasermin, a 2009 review of mecasermin named hypoglycaemia as the most frequent side effect, along with lymphoid tissue overgrowth, body-fat accumulation and coarsening of facial features, and noted that the anti-apoptotic properties of IGF-I are implicated in cancer pathogenesis, a concern for long-term therapy (Rosenbloom, 2009). A registry of 306 children and adolescents treated with mecasermin recorded at least one hypoglycaemia adverse event in 80 of them (Bang et al., 2023).

Separately, a 2026 Cochrane review of intravenous IGF-1 (as mecasermin rinfabate) in preterm infants, covering two trials and 140 infants, rated all evidence as very low certainty; a post hoc analysis of the larger trial (121 infants) found more serious adverse events with IGF-1 than with controls; the pooled analysis of both trials was very uncertain (RR 1.18, 95% CI 0.94 to 1.47) and the authors said they could not draw conclusions about serious adverse events (Trzaski et al., 2026). That product is not LR3 and the review is not evidence about it.

Oral route: what the evidence shows

Most evidence on LR3 concerns cell culture, animal infusion or injection. In neonatal calves, LR3 given orally had no effects on plasma glucose or insulin, while subcutaneous LR3 lowered both (Hammon and Blum, 1998). Laboratory digestion with pepsin showed LR3 is cleaved at several sites, and researchers engineered pepsin-resistant variants for that reason (Bryant et al., 1996). In newborn rat pups fed LR3 (Staley et al., 1998), villus height and cell counts were increased compared with pups fed rat milk replacer. Results from one route and species cannot be assumed to carry across to an oral capsule. For a broader look at that question, see our overview of oral peptides and the evidence.

Anti-doping science

Two reviews by Guha and colleagues explain why the anti-doping position matters. The 2013 review stated that no test was yet in place for detecting IGF-1 misuse and that IGF-1 compounds were advertised online and available on the black market, while a marker-based test was under development (Guha et al., 2013). The 2009 review stated that the long-term effects of IGF-1 administration were unknown and that detection was a challenge (Guha et al., 2009). We did not verify the current state of testing, so do not read these older reviews as a statement about detection today.

How to judge quality: the Certificate of Analysis explained

A Certificate of Analysis is the report an analytical laboratory issues after testing a specific batch. For a plain-English explanation of how to read the report, read how to read a Certificate of Analysis.

For an IGF-1 LR3 UK order, no single line proves quality on its own. Check them together, and match the batch number on the document to the batch number on the label in front of you. A COA for a different batch tells you nothing about yours.

How batch testing works at Free Muscle

Every Free Muscle batch of research compounds is assayed for identity and purity by Janoshik Analytical, an independent laboratory. You can read more in our explainer on what Janoshik Analytical is. For the product itself, see the IGF-1 LR3, 60 capsules product page.

The Certificate of Analysis for a batch is sent on request. Email the batch number printed on the label together with the product name. The full process is described on the lab tests page.

How to order from Free Muscle, step by step

1. Choose the listing. The IGF-1 LR3, 60 capsules product page is the listing for this compound. Other compounds sit in the peptides collection.
2. Add to basket and check out. Add the item to your basket, review it and continue to checkout as with any online order.
3. Age. Research compounds are sold only to customers aged 18 or over.
4. Delivery. UK delivery is free and tracked, in plain packaging. Standard UK delivery takes 2 to 5 working days, and orders placed before 2pm UK time Monday to Friday are processed the same working day. The shipping page has the details.
5. Check the label. When the parcel arrives, find the batch number printed on the label and keep it.
6. Request the COA. Email the batch number and the product name, and the Certificate of Analysis for that batch is sent to you.
7. Returns. Unopened items in their original packaging can be returned within 30 days under the guarantee. Apparel returns follow the refund policy.

That is the whole process: one listing, a batch number on the label and a COA on request. Free Muscle also sells gym apparel, in the merchandise collection, which is separate from the research compounds.

Frequently asked questions

Short answers to the questions most often asked about IGF-1 LR3 UK status, testing and ordering.

What should I check on an IGF-1 LR3 certificate of analysis before ordering?

Check seven lines together: a named independent laboratory, the batch number, the product name, an identity result, a purity figure, the test date and whether the report can be verified with the issuing laboratory. Match the batch number on the document to the label. Free Muscle batches are assayed for identity and purity by Janoshik Analytical, and the COA is sent on request.

Is IGF-1 LR3 legal in the UK?

In the UK, the law turns on how a product is presented and what it does. The Human Medicines Regulations 2012 prohibit selling unauthorised medicinal products, and the MHRA decides what counts as a medicine on presentation and function. This is general information, not legal advice.

Is IGF-1 LR3 banned in sport?

The WADA 2026 Prohibited List names IGF-1 and its analogues under S2, prohibited at all times. LR3 is an analogue, so it is understood to be covered. Check with UK Anti-Doping if you are subject to anti-doping rules.

Is IGF-1 LR3 the same as mecasermin?

No. Mecasermin is recombinant human IGF-1, described by the EMA in its Increlex EPAR as a prescription-only injection for severe primary IGF-1 deficiency. IGF-1 LR3 is a modified analogue with an extension at one end and an arginine substitution, and it is not Increlex.

What does "research use only" mean on a label?

It means the material is supplied for laboratory work and not as a medicine, a food supplement or for human consumption. It does not decide whether a product is a medicine in law, which the MHRA determines.

What is a Certificate of Analysis?

It is a report from an analytical laboratory about one batch. Free Muscle batches are assayed for identity and purity by Janoshik Analytical, and the COA is sent on request.

How do I request the COA for my batch?

Email the batch number printed on the label together with the product name. The process is on the lab tests page.

How long does UK delivery take?

Standard UK delivery takes 2 to 5 working days. It is free, tracked and sent in plain packaging, and orders placed before 2pm UK time Monday to Friday are processed the same working day.

Can I return an order?

Unopened items in their original packaging can be returned within 30 days. See the guarantee page for the conditions.

What age do I need to be to order?

Research compounds are sold only to customers aged 18 or over.

Has IGF-1 LR3 been tested in human trials?

None of the studies included in this guide's records tested IGF-1 LR3 in people. The 2026 narrative review of GH-IGF-1 axis research-compound peptides, which covers IGF-1 LR3, sorted peptides into evidence tiers running from regulatory-grade randomised trial data to a complete absence of human studies (Dominikowski et al., 2026).

Why do animal results differ so much between species?

The same analogue restored growth in diabetic rats (Tomas et al., 1993), did not stimulate overall growth in guinea pigs and reduced growth in pigs, according to the studies above. Conlon et al. (1995) noted that the guinea pig carries substantial IGF-II in its circulation whereas the adult rat has negligible amounts, and Dunaiski et al. (1997) noted that analogues that stimulate growth in the rat inhibit it in the pig. These results describe those animals only and cannot be assumed to apply to people.

Sources

1. Dominikowski A, Rękoś Z, Olejarz M, Szczepanek-Parulska E, Domin R, Ruchała M. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration. Front Endocrinol (Lausanne). 2026;17:1822475. doi:10.3389/fendo.2026.1822475. PMID 42395176
2. Tomas FM, Knowles SE, Owens PC, Chandler CS, Francis GL, Ballard FJ. Insulin-like growth factor-I and more potent variants restore growth of diabetic rats without inducing all characteristic insulin effects. Biochem J. 1993;291(Pt 3):781-6. doi:10.1042/bj2910781. PMID 7683875
3. Conlon MA, Tomas FM, Owens PC, Wallace JC, Howarth GS, Ballard FJ. Long R3 insulin-like growth factor-I (IGF-I) infusion stimulates organ growth but reduces plasma IGF-I, IGF-II and IGF binding protein concentrations in the guinea pig. J Endocrinol. 1995;146(2):247-53. doi:10.1677/joe.0.1460247. PMID 7561636
4. Dunaiski V, Dunshea FR, Walton PE, Goddard C. Long [R3] insulin-like growth factor-I reduces growth, plasma growth hormone, IGF binding protein-3 and endogenous IGF-I concentrations in pigs. J Endocrinol. 1997;155(3):559-65. doi:10.1677/joe.0.1550559. PMID 9488001
5. Tomas FM, Chandler CS, Coyle P, Bourgeois CS, Burgoyne JL, Rofe AM. Effects of insulin and insulin-like growth factors on protein and energy metabolism in tumour-bearing rats. Biochem J. 1994;301(Pt 3):769-75. doi:10.1042/bj3010769. PMID 8053901
6. Hill RA, Hunter RA, Lindsay DB, Owens PC. Action of long(R3)-insulin-like growth factor-1 on protein metabolism in beef heifers. Domest Anim Endocrinol. 1999;16(4):219-29. doi:10.1016/s0739-7240(99)00015-6. PMID 10370861
7. Prelle K, Stojkovic M, Boxhammer K, Motlik J, Ewald D, Arnold GJ, Wolf E. Insulin-like growth factor I (IGF-I) and long R(3)IGF-I differently affect development and messenger ribonucleic acid abundance for IGF-binding proteins and type I IGF receptors in in vitro produced bovine embryos. Endocrinology. 2001;142(3):1309-16. doi:10.1210/endo.142.3.8038. PMID 11181549
8. Pesall JE, McFarland DC, McMurtry JP, Clapper JA, Francis GL, Gilkerson KK. The effect of insulin-like growth factor analogs on turkey satellite cell and embryonic myoblast proliferation. Poult Sci. 2001;80(7):944-8. doi:10.1093/ps/80.7.944. PMID 11469659
9. Hammon H, Blum JW. Endocrine and metabolic changes in neonatal calves in response to growth hormone and long-R3-insulin-like growth factor-I administration. Biol Neonate. 1998;73(2):121-8. doi:10.1159/000013968. PMID 9483305
10. Bryant KJ, Read LC, Forsberg G, Wallace JC. Design and characterisation of long-R3-insulin-like growth factor-I muteins which show resistance to pepsin digestion. Growth Factors. 1996;13(3-4):261-72. doi:10.3109/08977199609003227. PMID 8919033
11. Staley MD, Gibson CA, Herbein JF, Grosvenor CE, Baumrucker CR. Rat milk and dietary long arginine3 insulin-like growth factor I promote intestinal growth of newborn rat pups. Pediatr Res. 1998;44(4):512-8. doi:10.1203/00006450-199810000-00008. PMID 9773839
12. Guha N, Cowan DA, Sönksen PH, Holt RI. Insulin-like growth factor-I (IGF-I) misuse in athletes and potential methods for detection. Anal Bioanal Chem. 2013;405(30):9669-83. doi:10.1007/s00216-013-7229-y. PMID 23934394
13. Guha N, Sönksen PH, Holt RI. IGF-I abuse in sport: current knowledge and future prospects for detection. Growth Horm IGF Res. 2009;19(4):408-11. doi:10.1016/j.ghir.2009.04.017. PMID 19467615
14. Rosenbloom AL. Mecasermin (recombinant human insulin-like growth factor I). Adv Ther. 2009;26(1):40-54. doi:10.1007/s12325-008-0136-5. PMID 19198769
15. Bang P, Polak M, Bossowski A, Maghnie M, Argente J, Ramon-Krauel M, et al. Frequency and predictive factors of hypoglycemia in patients treated with rhIGF-1: data from the Eu-IGFD registry. J Clin Endocrinol Metab. 2023;109(1):46-56. doi:10.1210/clinem/dgad479. PMID 37579214
16. Trzaski JM, Cracknell J, Herbst KW, Iverson MG, Quinn GE, Sink DW, Hagadorn JI. Insulin-like growth factor-1 for the prevention or treatment of retinopathy of prematurity. Cochrane Database Syst Rev. 2026;4(4):CD013216. doi:10.1002/14651858.CD013216.pub2. PMID 41983451
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19. Human Medicines Regulations 2012, regulations 46 and 220. legislation.gov.uk
20. MHRA. Borderline products: how to tell if your product is a medicine. gov.uk
21. MHRA. Personal trainer jailed for sale of steroids and unlicensed medicines online, 28 May 2021. gov.uk
22. European Medicines Agency. Increlex (mecasermin) EPAR. ema.europa.eu
23. World Anti-Doping Agency. Prohibited List 2026. wada-ama.org
24. UK Anti-Doping. What is banned in sport: the Prohibited List. ukad.org.uk