Ipamorelin
1 product from 1 brand · free UK delivery · EU 3–7 days
Ipamorelin (also written NNC 26-0161) is a synthetic pentapeptide growth hormone secretagogue, a five-amino-acid chain that acts as a selective agonist at the ghrelin receptor, GHS-R1a. It belongs to the growth hormone releasing peptide family alongside GHRP-6 and GHRP-2, and shares its receptor with the non-peptide compound MK-677. This page lists every brand of ipamorelin stocked at Free Muscle, compared on pack size, form and batch testing, and explains what the published research does and does not cover. Research use only, 18+.
What is ipamorelin?
Ipamorelin has the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2. It was identified in the 1990s from a chemistry programme that stripped the central Ala-Trp dipeptide out of the earlier growth hormone releasing peptide GHRP-1, and was first described in full in 1998. Like the other members of its family it binds the growth hormone secretagogue receptor on pituitary somatotrophs and triggers a pulse of growth hormone release. What set it apart in the original animal work was selectivity: unlike GHRP-6 and GHRP-2, it did not raise ACTH or cortisol, and it left FSH, LH, prolactin and TSH unchanged.
Ipamorelin went into human pharmacokinetic studies and later into a phase 2 clinical trial for postoperative ileus, a slowing of the gut after bowel surgery. That trial did not meet its efficacy endpoints and development was discontinued. Ipamorelin has never been approved as a medicine anywhere. In the UK it is not a licensed medicine and not an authorised food supplement. It is also a peptide, which matters for a capsule product: peptides taken by mouth are largely broken down by digestive enzymes, which is why every human study of ipamorelin used intravenous infusion. Our article Do oral peptides actually work? covers that problem honestly.
What the published research reports
Raun and colleagues (1998) characterised ipamorelin in rat pituitary cells, anaesthetised rats and conscious pigs. It released growth hormone with a potency and efficacy similar to GHRP-6, and in pigs it did not raise ACTH or cortisol even at doses more than 200-fold above the level needed for half-maximal growth hormone release. This is the source of the compound's reputation for selectivity, and it is an animal study.
Gobburu and colleagues (1999) gave intravenous infusions of ipamorelin to healthy male volunteers, eight at each of five infusion rates. Pharmacokinetics were dose-proportional, with a terminal half-life of about two hours. Each infusion produced a single episode of growth hormone release, peaking at about 40 minutes and falling back to negligible levels; the variability of the growth hormone response between individuals was larger than the variability in pharmacokinetics.
Beck and colleagues (2014) ran a multicentre, double-blind, placebo-controlled phase 2 trial in 117 adults recovering from bowel resection. Intravenous ipamorelin given for up to seven days after surgery was described as well tolerated, but the median time to tolerating a first solid meal was 25.3 hours against 32.6 hours on placebo, a difference that was not statistically significant, and no secondary endpoint differed from placebo either.
Johansen and colleagues (1999) reported that ipamorelin increased longitudinal bone growth in growing rats, which is again an animal finding. None of these results is a claim about the capsules listed on this page. They describe injected peptide in animals and in supervised human studies, and the compound did not succeed in its one clinical trial.
Brands of ipamorelin we stock
- Free Muscle Ipamorelin, Research Peptide: Free Muscle brand, capsule form, 60 capsules per bottle. Every batch is assayed for identity and purity by Janoshik Analytical, with the certificate sent on request. The listing states the declared peptide quantity per capsule where one is given; where it is not, we do not state a figure here.
This collection currently holds one listing. Any other brand of ipamorelin stocked in future would be listed here with its capsule count, declared quantity and batch-certificate status. Related peptides we stock are listed in the peptides collection.
How to compare them
Multiply the declared quantity per capsule by the number of capsules to get total peptide per bottle, then divide the listed price by that figure. Where a manufacturer does not declare a quantity per capsule, that calculation cannot be done and no honest cost per milligram exists; treat that as information in itself. Peptides also degrade more readily than small molecules, so the date and batch on the certificate matter more than they do for a compound like MK-677. See price per milligram for the method.
Batch testing and certificates of analysis
A Certificate of Analysis for a peptide batch should report identity, normally by HPLC and mass spectrometry confirming the expected molecular mass, and purity as a percentage, together with the batch number, test date and the laboratory that performed the work. Every Free Muscle batch is assayed by Janoshik Analytical, an independent laboratory; email us the batch number from your label with the product name and we send the certificate for that batch. For other brands we show a certificate only where the manufacturer supplies one for the batch we hold. A generic PDF without a batch number is not a batch certificate. Our lab tests page and the article How to read a COA explain the detail.
Legal status in the UK
Ipamorelin is not a licensed medicine in the UK, holds no MHRA marketing authorisation and is not an authorised food supplement or novel food. It cannot be sold for human consumption, and Free Muscle supplies it for laboratory research only, to adults aged 18 or over. Under section S2 of the WADA Prohibited List, growth hormone secretagogues and growth hormone releasing peptides are prohibited at all times, so ipamorelin is incompatible with tested sport. For a wider look at how peptides differ from SARMs in UK law and in research, see SARMs vs Peptides.
Storage and handling
Peptides are less stable than small-molecule compounds. Keep the sealed bottle in a cool, dry place away from light and heat, and follow any storage instruction on the label. Reseal promptly after opening and do not transfer capsules to unlabelled containers. Record the batch number and date of receipt. Keep out of reach of children and pets and apply normal laboratory good practice.
Delivery and returns
Free Muscle is a UK company, FreeMuscle LTD of Scunthorpe. Orders ship with free tracked UK delivery in plain packaging, and orders placed before 2pm Monday to Friday are processed the same working day. EU delivery takes 3 to 7 working days. Unopened items can be returned within 30 days. See delivery and our 30-day guarantee.
Related reading
- Do Oral Peptides Actually Work? The Honest Answer
- SARMs vs Peptides: Choosing by Goal
- How to Read a Certificate of Analysis (COA)
- What Is Janoshik Analytical? Third-Party Testing Explained
Ipamorelin 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. Customers must be 18 or over. Nothing on this page is medical advice or dosing guidance, and the published findings summarised above describe animals and supervised study participants, not the products listed.
Frequently asked questions
Is ipamorelin legal in the UK?
Ipamorelin is not a controlled drug in the UK, but it is not a licensed medicine and not an authorised food supplement, so it cannot be sold for human consumption. Free Muscle supplies it for laboratory research to adults aged 18 or over. It is prohibited in sport under the WADA list as a growth hormone releasing peptide.
Is ipamorelin a peptide or a SARM?
A peptide. Ipamorelin is a chain of five amino acids that acts at the ghrelin receptor to stimulate growth hormone release. SARMs are small molecules acting at the androgen receptor and have nothing in common with it pharmacologically. It is often sold beside SARMs, but it belongs to the growth hormone secretagogue class.
What is the difference between ipamorelin and MK-677?
Both act at the same receptor, GHS-R1a, but ipamorelin is a peptide with a half-life of about two hours in the human infusion study, while MK-677 is a non-peptide small molecule that is orally active and was studied in trials lasting up to two years. MK-677 has a much larger human literature. Ipamorelin's selectivity for growth hormone over cortisol comes from animal work.
Does ipamorelin work in capsule form?
We do not make that claim. Every published human study of ipamorelin used intravenous infusion, and peptides taken by mouth are largely broken down by digestive enzymes before they can be absorbed. Our capsules are supplied for laboratory research. Our article on oral peptides sets out the evidence on absorption without spin.
How do I verify the batch of ipamorelin I have?
Find the batch number on the label. For Free Muscle brand, email it to us with the product name and we send the Janoshik Analytical certificate for that batch, which reports identity and purity. Check that the batch number on the certificate matches your bottle. For other brands, a certificate is shown only where the manufacturer has supplied one for the batch we hold.
Is ipamorelin detectable in anti-doping tests?
Ipamorelin is prohibited at all times under the WADA list, and accredited laboratories have published detection methods for growth hormone releasing peptides and their metabolites in urine. Anyone subject to anti-doping rules should treat it as a banned substance. Its short half-life does not make it undetectable.
How is ipamorelin shipped and can I return it?
Every order ships with free tracked UK delivery in plain packaging, with no reference to the contents on the outside. Orders placed before 2pm Monday to Friday are processed the same working day, and EU delivery takes 3 to 7 working days. Unopened items in original packaging can be returned within 30 days. Customers must be 18 or over.