Ipamorelin | Reviews, Clinical Trials, and Safety

Ipamorelin is a pentapeptide that stimulates the body's ghrelin receptors. Potential research applications for Ipamorelin include muscle growth, body composition, and more.

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    Compound Overview

    Class of Compound:


    Mechanism of Action:

    A selective growth hormone secretagogue and ghrelin receptor agonist, ipamorelin triggers and stimulates growth hormone production by mimicking ghrelin. It binds to ghrelin receptors, stimulates the release of somatocrinin, and inhibits somatostatin and suppresses its action.

    Notable Studies:

    Also Known As:

    NNC 26-0161

    Research Applications:

    • Muscle growth
    • Weight management
    • Injury recovery
    • Anti-aging


    • Prohibited by WADA
    • Did not complete clinical trials
    • No FDA review or approval

    Chemical Structure

    Ipamorelin chemical structure

    What is Ipamorelin?

    Ipamorelin is a type of lab-made compound known as a growth hormone releasing peptide. It stimulates the body to release growth hormone, which promotes the systemic growth of muscle, bone, vasculature, and other cells and body tissues.

    Ipamorelin is unique among growth hormone releasing peptides in that, unlike most, it does not activate the body’s natural stress response. This gives ipamorelin an advantage over other compounds in its class.

    However, research on ipamorelin is lacking — and there’s little definitive information available about the potential side effects or most advantageous doses for subjects.

    Read below for more specifics on the pharmacology, benefits, side effects, dosage recommendations, and legality of ipamorelin — along with our recommendation for the best place to buy ipamorelin online.


    What Does Ipamorelin Do?

    Ipamorelin is a growth hormone releasing peptide. It stimulates the pituitary gland to release growth hormone, which encourages cell and tissue proliferation. Ipamorelin acts much like the hormone ghrelin, which also stimulates growth hormone [1].

    Ipamorelin is synthetic, and composed of five amino acids. Its amino acid structure is as follows: H-Aib-His-D-2Nal-D-Phe-Lys-NH2, and its chemical structure is C38H49N9O5 [2].

    As a ghrelin mimetic, ipamorelin binds to ghrelin receptors in the pituitary gland and stimulates the release of an intermediary hormone, growth hormone stimulating hormone. Growth hormone stimulating hormone then signals for growth hormone to be released.

    However, ipamorelin has a distinct advantage over other ghrelin mimetics. While others also activate the body’s stress response, causing a number of other physical and biochemical changes in the body, ipamorelin is extremely targeted. It does not appear to activate the stress response, making it more of a “pure” growth hormone releasing peptide [3].

    Ipamorelin Benefits | Clinical Trials

    There are several potential benefits of ipamorelin, all stemming from its effect on growth hormone. Ipamorelin stimulates the ghrelin receptor, which is a hormone that signals for the pituitary gland to release growth hormone [3].

    There is a lot of interest in ipamorelin because, unlike other growth hormone releasing peptides, it is extremely targeted to growth hormone — with minimal effects on other hormones or biochemical processes [3].

    Promotes bone growth: A few animal studies have noted the bone growth stimulating effects of ipamorelin.

    In one, researchers found that ipamorelin administration could counteract the skeletal muscle catabolism induced by glucocorticoids [4].

    A similar study noted that ipamorelin administration in female rats resulted in increased bone mineral content, which is suggestive of stronger, denser bones [5].

    Additionally, in one of the earliest studies done on ipamorelin (published in 1999), researchers found that ipamorelin administration actually appeared to increase the length of long bones in rats — particularly the tibia, a leg bone [6].

    These findings are promising for future research in the fields of anti-aging, stunted growth, injury recovery, and women’s health — as women are at an increased risk of poor bone density as they age.

    Stimulates muscle growth: One of the most widely reported effects of ipamorelin is that it can stimulate muscle growth. Considering ipamorelin and other growth hormone releasing peptides are banned from use in competitive sports, there may in fact be a connection between muscle growth and ipamorelin.

    However, published scientific research has not yet shown this effect definitively.

    Researchers have found that ipamorelin can stimulate the smooth muscle of the digestive lining to help food move more quickly through the digestive system [7].

    Regardless, this is a far cry from the effects on skeletal muscle that have been reported by some independent researchers.

    However, the same study mentioned above that noted ipamorelin could neutralize the negative effect of glucocorticoids on bone found similar results for skeletal muscle. Researchers found that muscle strength was significantly higher in rats who were injected with both ipamorelin and glucocorticoid in comparison to rats who were only injected with glucocorticoids [4].

    Improves vasculature: Ipamorelin has a similar effect as ghrelin, a naturally occurring hormone in the body.

    Ghrelin may stimulate angiogenesis, or the growth of new blood vessel networks. Researchers noted this when they found that ghrelin deficient mice had fewer blood vessels in their white fat tissue than other mice [8].

    Because ipamorelin is a ghrelin mimetic, it may also have this effect — which would be of great interest to heart health and physical performance researchers. However, this effect has not been specifically noted as a result of ipamorelin administration to date.

    Increases collagen synthesis. Some research suggests that ghrelin may help promote growth, regrowth, or repair of the cartilage, joints, and skin thanks to its potential effects on collagen, the springy protein matrix that forms the bulk of these tissues.

    One study noted that ghrelin may upregulate cartilage-specific genes, and another noted that ghrelin may help mesenchymal stem cells (“universal” stem cells that can differentiate based on need) to target cartilage repair [9, 10].

    Once again, however, this effect has been noted from ghrelin, but not from ipamorelin specifically.

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    Ipamorelin Side Effects

    Side effects of ipamorelin appear to be minimal. The small handful of human studies that made note of side effects found either no reported side effects or a couple of minor side effects.

    In one study, researchers found that subjects experienced mild flushing in the face after growth hormone releasing peptide administration [11]. Another study in children had no reported side effects [12].

    Ipamorelin and other growth hormone releasing peptides may also increase hunger, as its function mimics the function of ghrelin, the “hunger hormone” that increases appetite [13].

    Regardless, human research is extremely lacking, so it’s important to recognize that there may be side effects of ipamorelin that are not known at this time. Utmost caution should be exercised in all research involving ipamorelin.

    Is Ipamorelin Safe?

    The peptide ipamorelin has not been approved for use in humans by the United States Food and Drug Administration (FDA), nor by any of its international regulatory counterparts. Accordingly, be wary of any claims or statements that ipamorelin is 100% safe.

    Nonetheless, in published research to date, ipamorelin administration has produced minimal side effects in animal and human studies alike [11, 12]. It is worth noting that this research is longstanding, with some of the earliest studies dating back to 1998. In fact, growth hormone releasing peptides were discovered several years prior, starting with GHRP-6 and GHRP-2, as scientists were particularly interested in their benefits for heart health [14].

    Researchers should note that despite ipamorelin’s favorable safety profile, peptide administration in general is associated with injection site pain, lightheadedness, nausea, and even flu-like symptoms in subjects. There have been very limited reports of ipamorelin causing even such minor side effects. On the contrary, it appears that ipamorelin is very well tolerated among a range of subjects.

    As with any research involving peptides, due caution is required when administering ipamorelin, which should be handled only by qualified researchers or laboratory professionals.

    Ipamorelin Dosage Calculator

    Due to the overall lack of published research involving ipamorelin, there are no firm dosing guidelines or recommendations for ipamorelin. In clinical practice, patients will receive a prescription for ipamorelin with dosage guidelines, which likely vary from clinic to clinic and physician to physician.

    For research purposes, a typical ipamorelin dose can range from 200 mcg to 300 mcg per day. For testing on a first-time ipamorelin subject, it is important to begin with the lowest dose and titrate up as needed.

    Additionally, ipamorelin is commonly injected daily in cycles of 8-12 weeks, followed by 4 weeks off. Ipamorelin is not something that should be administered indefinitely or continuously — regardless of the research application. Also, daily doses of 200mcg or more may be split up into 2 or 3 injections per day.

    The best maintenance dose of ipamorelin depends heavily on research objectives. For anti-aging and/or weight loss, doses on the lower end of the spectrum appear to be better. However, to promote significant muscle or bone growth, a higher dose may be warranted.


    Where to Buy Ipamorelin Online? | 2024 Edition

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    Bacteriostatic Water and Ipamorelin

    Experienced researchers agree that no lab is complete without the correct tools. This is especially true when handling Ipamorelin and all other research peptides.

    To adhere to the standard measures of peptide storage and handling, researchers must have materials like bacteriostatic water and sterile vials at your disposal.


    Ipamorelin | Reviews

    Ipamorelin is a growth hormone stimulating peptide composed of five amino acids. It promotes the release of growth hormone, which provides many positive effects on body composition, collagen synthesis, muscle and bone growth, heart health, aging, and more.

    There also appear to be few side effects of ipamorelin, and the ones that have been identified are mild and transient.

    Most research subjects are given an ipamorelin dose of 200-300 mcg per day, for 8-12 weeks, followed by a 4 week washout period.

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    1. N Mohammadi E, Louwies T, Pietra C, Northrup SR, Greenwood-Van Meerveld B. Attenuation of Visceral and Somatic Nociception by Ghrelin Mimetics. J Exp Pharmacol. 2020;12:267-274. Published 2020 Aug 5. doi:10.2147/JEP.S249747
    2. National Center for Biotechnology Information. PubChem Compound Summary for CID 9831659, Ipamorelin. https://pubchem.ncbi.nlm.nih.gov/compound/Ipamorelin. Accessed Oct. 12, 2021.
    3. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. doi:10.1530/eje.0.1390552
    4. Andersen NB, Malmlöf K, Johansen PB, Andreassen TT, Ørtoft G, Oxlund H. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats. Growth Horm IGF Res. 2001;11(5):266-272. doi:10.1054/ghir.2001.0239
    5. Svensson J, Lall S, Dickson SL, et al. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats. J Endocrinol. 2000;165(3):569-577. doi:10.1677/joe.0.1650569
    6. Johansen PB, Nowak J, Skjaerbaek C, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106-113. doi:10.1054/ghir.1999.9998
    7. Greenwood-Van Meerveld B, Tyler K, Mohammadi E, Pietra C. Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus. J Exp Pharmacol. 2012;4:149-155. Published 2012 Oct 19. doi:10.2147/JEP.S35396
    8. Wang J, He L, Huwatibieke B, et al. Ghrelin Stimulates Endothelial Cells Angiogenesis through Extracellular Regulated Protein Kinases (ERK) Signaling Pathway. Int J Mol Sci. 2018;19(9):2530. Published 2018 Aug 26. doi:10.3390/ijms19092530
    9. Liang ZT, Li J, Rong R, et al. Ghrelin up-regulates cartilage-specific genes via the ERK/STAT3 pathway in chondrocytes of patients with adolescent idiopathic scoliosis. Biochem Biophys Res Commun. 2019;518(2):259-265. doi:10.1016/j.bbrc.2019.08.044
    10. Fan L, Chen J, Tao Y, et al. Enhancement of the chondrogenic differentiation of mesenchymal stem cells and cartilage repair by ghrelin. J Orthop Res. 2019;37(6):1387-1397. doi:10.1002/jor.24224
    11. Mericq V, Cassorla F, Salazar T, et al. Effects of eight months treatment with graded doses of a growth hormone (GH)-releasing peptide in GH-deficient children. J Clin Endocrinol Metab. 1998;83(7):2355-2360. doi:10.1210/jcem.83.7.4969
    12. Bowers CY, Reynolds GA, Durham D, Barrera CM, Pezzoli SS, Thorner MO. Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone. J Clin Endocrinol Metab. 1990;70(4):975-982. doi:10.1210/jcem-70-4-975
    13. Laferrère B, Abraham C, Russell CD, Bowers CY. Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men. J Clin Endocrinol Metab. 2005;90(2):611-614. doi:10.1210/jc.2004-1719
    14. Berlanga-Acosta J, Abreu-Cruz A, Herrera DGB, et al. Synthetic Growth Hormone-Releasing Peptides (GHRPs): A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects. Clin Med Insights Cardiol. 2017;11:1179546817694558. Published 2017 Mar 2. doi:10.1177/1179546817694558
    15. World Anti-Doping Agency. World Anti-Doping Code International Standard Prohibited List 2022. WADA website. January 1, 2022. Accessed Mar 2022. https://www.wada-ama.org/sites/default/files/resources/files/2022list_final_en.pdf