MK-677 Ibutamoren

MK-677 Ibutamoren – ghrelin receptor agonist for studies of the GH/IGF-1 axis

MK-677 (Ibutamoren) is a non-peptide agonist of the growth hormone secretion receptor GHS-R1a, acting as a ghrelin mimetic. It is a small organic molecule, which distinguishes it from peptide GH secretagons such as GHRP-6 or Ipamorelin. In studies on animal and cell models, MK-677 activates the GHS-R1a receptor, stimulating the release of growth hormone and modulating the GH/IGF-1 axis. CAS: 159634-47-6. MK-677 is not a medicinal product – it is intended for research use only. Browse the available Ibutamoren variants in the One Peptides offer.

What is MK-677?

MK-677, known as Ibutamoren (Ibutamoren mesylate), is a synthetic small organic molecule belonging to the class of growth hormone secretagogues (GHS). It was developed by Merck & Co. in cooperation with Reverse Pharmacology.

The mechanism of action of MK-677 is based on agonism towards the GHS-R1a receptor (Growth Hormone Secretagogue Receptor type 1a) – the same receptor that is the natural target of ghrelin. When bound to GHS-R1a in somatotropic pituitary cells, MK-677 stimulates the release of growth hormone (GH) in a pulsatile manner, maintaining the physiological secretion pattern. An increase in IGF-1 (insulin-like growth factor 1) levels was also observed in experimental models.

An important feature of MK-677 is its non-peptide nature – unlike GHRP-6, GHRP-2 or Ipamorelin, which are peptides, MK-677 is a small organic molecule. The compound’s CAS number is 159634-47-6. Studies on animal models have shown that MK-677 does not significantly affect the levels of cortisol and prolactin at concentrations that modulate GH secretion, which suggests a relative selectivity of action.

MK-677 variants available

The product is supplied with a Certificate of Analysis (CoA). Detailed specifications, including HPLC and MS results, are available on the product card.

Which MK-677 variant should you choose?

One Peptides offer includes one variant, MK-677 – capsules containing 10 mg of Ibutamoren in a package of 60 pieces. This form is suitable both for preliminary in vitro studies (e.g. GHS-R1a receptor activation tests on cell lines, intracellular signaling assays – Ca2+ pathway, MAPK), as well as for more extensive experimental protocols in animal models involving repeated administration and measurement of GH/IGF-1 levels in serum.

The product has purity confirmed by independent analyses.

How is MK-677 different from similar compounds?

MK-677 vs Ipamorelin
Both compounds are GHS-R1a receptor agonists, but they differ fundamentally in their chemical nature. MK-677 is a small organic molecule (non-peptide), while Ipamorelin is a pentapeptide (5 amino acids). This structural difference translates into different physicochemical properties – MK-677 is stable in an acidic environment, while Ipamorelin, as a peptide, is subject to enzymatic degradation. In studies on animal models, both compounds stimulate GH secretion, but Ipamorelin shows higher selectivity – it does not affect ACTH and cortisol levels. You can find more about Ipamorelinue in the category Ipamorelin.

MK-677 vs GHRP-6
GHRP-6 (Growth Hormone Releasing Peptide-6) is a hexapeptide that also activates the GHS-R1a receptor. Compared to MK-677, GHRP-6 shows stronger appetite stimulation in experimental models (via the same ghrelin receptor) and a greater effect on prolactin and cortisol levels. MK-677, as a non-peptide molecule, does not require parenteral administration in animal models. Category GHRP-6.

MK-677 vs CJC-1295
This comparison concerns two different molecular targets. MK-677 activates the GHS-R1a receptor (ghrelin receptor), while CJC-1295 is an analogue of GHRH (growth hormone releasing hormone) and acts on the GHRH-R receptor. In animal models, both compounds stimulate GH secretion, but through different pathways – GHS-R1a and GHRH-R act synergistically on somatotropic cells. Check the category CJC-1295.

FAQ – Frequently asked questions

1. Is MK-677 a peptide?
NO. MK-677 is a small organic molecule (non-peptide) that mimics the action of ghrelin at the GHS-R1a receptor. This distinguishes it from peptide GH secretagons such as GHRP-6, GHRP-2 or Ipamorelin, which are amino acid chains.

2. Is MK-677 a SARM?
NO. MK-677 is not a selective androgen receptor modulator. It does not bind to the androgen receptor. It is a ghrelin receptor agonist (GHS-R1a) and acts on the growth hormone/IGF-1 axis, not on androgen pathways.

3. Is MK-677 a medicinal product?
NO. MK-677 offered at One Peptides is a compound intended solely for research purposes (Research Use Only). It is not a medicine, dietary supplement or product for use on humans.

4. What is the primary molecular target of MK-677?
The main target of MK-677 is the GHS-R1a receptor (Growth Hormone Secretagogue Receptor type 1a), also known as the ghrelin receptor. Activation of this receptor in somatotropic pituitary cells leads to the release of growth hormone in experimental models.

5. How to store MK-677?
MK-677 should be stored in a dry, dark place at room temperature or lower. The packaging should be tightly closed. Detailed storage conditions are provided on the product data sheet and in the safety data sheet (SDS).

Quality and standards at One Peptides

Each batch of MK-677 undergoes purity analysis by HPLC and molecular weight verification by mass spectrometry (MS). Each order is accompanied by a certificate of analysis (CoA) and a safety data sheet (SDS). Our quality control procedures guarantee compliance of parameters with the declared specifications.