Hexarelin 5mg Nasal Spray

Description

This hexarelin nasal spray supplies hexarelin, a synthetic hexapeptide with the sequence His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂, molecular weight approximately 887.04 Da, CAS 140703-51-1. It belongs to the growth hormone-releasing peptide family, and on most product pages that is where the description stops. It should not, because hexarelin has a second receptor, and the second receptor is where the more interesting research sits. Supplied for laboratory research use only.

CD36 is the reason this compound is not interchangeable

Hexarelin engages two distinct receptor populations. The first is GHS-R1a, the ghrelin receptor, which mediates GH release from the pituitary and which it shares with the rest of the family. The second is CD36, a multifunctional scavenger receptor glycoprotein expressed on cardiomyocytes and microvascular endothelial cells.

CD36 was identified as a hexarelin binding partner using a radioactive photoactivatable derivative of the peptide, which pulled down an 84 kDa binding protein. Bodart and colleagues, publishing in Circulation Research in 2002, reported that CD36 mediates the cardiovascular action of growth hormone-releasing peptides in the heart. Activating CD36 in perfused hearts with hexarelin raised coronary perfusion pressure in a dose-dependent way.

The finding that matters most is the dissociation. Hexarelin protected hearts against ischemia-reperfusion damage in GH-deficient rats, and the effect was independent of any stimulation of the somatotropic axis. In other words the cardiac action does not run through growth hormone, which means an experiment measuring GH output is not measuring this half of the compound at all.

For anyone designing work with hexarelin, that dual pharmacology is the central design constraint. A GHS-R1a-only assay system misses the CD36 arm entirely, and a cardiac preparation expressing CD36 will respond in ways a pituitary preparation never shows you. Confirming which receptor your model expresses is the step that decides what your result can mean.

The 2-methyl-tryptophan is a stability modification

Position 2 carries D-2-methyl-tryptophan, and that residue was chosen deliberately. Adding the methyl group to the tryptophan indole makes the peptide more resistant to proteolytic degradation than the unmethylated version, so hexarelin persists longer in a biological matrix than the parent hexapeptide it was derived from.

The trade-off is worth stating. Hexarelin is also the member of this family most associated with desensitization on repeated exposure, and a longer-lived agonist at a receptor with high constitutive activity is exactly the combination that produces tachyphylaxis. If your protocol involves repeated dosing of a culture, expect a declining response and design a washout rather than treating the decline as a result.

The constitutive activity problem applies here too

GHS-R1a has the highest known constitutive activity of any G protein-coupled receptor, signalling at roughly half its maximal capacity with no agonist present, as reviewed in work on GHS-R1a constitutive activity. Your unstimulated baseline sits near the middle of the receptor’s range rather than at the bottom of it, which compresses the window an agonist has to work in.

With hexarelin the practical fix is to run two controls rather than one. Vehicle establishes where the constitutive floor is. An inverse agonist establishes how much of the observed signal is receptor-dependent at all. Structural work on the receptor, including cryo-EM structures deposited as PDB 7W2Z, has begun to explain where that basal activity comes from.

Hexarelin nasal spray specifications

Core identity data for this hexarelin nasal spray. Quote the sequence and CAS number in your methods section, and state which receptor your model expresses.

In-vitro models for a two-receptor compound

The model has to match the receptor arm you are asking about, and this is where intranasal hexarelin research and cell work most often go wrong.

For the GHS-R1a arm, recombinant lines expressing human GHS-R1a give inositol phosphate and calcium readouts, and primary pituitary or somatotroph-derived cultures give GH secretion by immunoassay. For the CD36 arm, cardiomyocyte preparations, microvascular endothelial cells and isolated perfused heart models are the relevant systems, with contractile function, perfusion pressure and injury markers under ischemia-reperfusion as the endpoints.

The control that makes a CD36 claim defensible is receptor-specific: either a CD36-null or CD36-knockdown comparison, or a GHS-R1a-selective agonist such as ipamorelin run in parallel. If a selective GHS-R1a agonist reproduces your effect, the effect is not CD36-mediated. That single comparison separates the two arms cleanly, and its absence is the most common weakness in hexarelin cardiac work.

Hexarelin nasal spray storage and handling

The methylated tryptophan improves enzymatic stability but does nothing for photostability, and this peptide contains two tryptophan residues. Tryptophan is among the most light-sensitive and oxidation-prone amino acids, so light protection is the specific requirement here, not generic advice. Amber containers or foil, short bench time, and discarding discoloured solution are all justified.

Otherwise sensible hexarelin nasal spray storage is routine: cold, sealed, single-use aliquots rather than repeated freeze-thaw, and low-binding plasticware at low working concentrations.

How research grade hexarelin spray is characterized

Two verification points are specific to this molecule. The 2-methyl-tryptophan at position 2 is a non-standard residue and it is what distinguishes hexarelin from the unmethylated parent compound, so confirming its presence matters. And the peptide contains two D-configured residues whose stereochemistry mass spectrometry cannot resolve, since D and L forms are isobaric, so chiral analysis or a validated synthetic route is the relevant assurance.

A research grade hexarelin spray is characterized by reversed-phase HPLC for purity and mass spectrometry for identity near 887.04 Da. This material is supplied under the same verification PrymaLab applies across its research peptides, HPLC and MS confirmation plus independent third-party testing. No specific lot figures are asserted here; request the certificate of analysis for the lot you receive.

For the GH-axis signalling behind this compound class, see CJC-1295 and Hexarelin GH Signaling in the PrymaLab Research Library.

Frequently asked questions

What is hexarelin?

Hexarelin is a synthetic hexapeptide, His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2, about 887.04 Da, CAS 140703-51-1. It acts at both GHS-R1a and CD36. Material supplied here is a research chemical for in-vitro laboratory use only.

What is CD36 and why does it matter for hexarelin?

CD36 is an 84 kDa scavenger receptor expressed on cardiomyocytes and microvascular endothelial cells. It was identified as a hexarelin binding partner and mediates the cardiovascular actions of growth hormone-releasing peptides, which are reported to be largely independent of GH release.

Are hexarelin’s cardiac effects caused by growth hormone?

Reportedly not. Hexarelin protected hearts from ischemia-reperfusion damage in GH-deficient rats independently of somatotropic axis stimulation. The cleanest control is a GHS-R1a-selective agonist run in parallel: if it reproduces the effect, the effect is not CD36-mediated.

Why is hexarelin prone to desensitization?

Because the 2-methyl-tryptophan modification makes it longer-lived, and a persistent agonist at a receptor with very high constitutive activity is the combination that produces tachyphylaxis. Repeated dosing without washout usually produces a declining response rather than a stable one.

Is hexarelin nasal spray approved for human use?

No. This material is a research chemical for in-vitro laboratory use only and is not intended for human or veterinary use. It is not an approved drug for any indication. Nothing here is medical advice.

Ordering and compliance

Every PrymaLab research compound ships from the United States and is sold research-use-only. This hexarelin nasal spray is supplied for in-vitro laboratory research, is not intended for human or veterinary use, is not a drug, supplement or sports product, and has not been evaluated by the FDA for the research-chemical context. Verify the legal status of any research compound in your jurisdiction before ordering. Certificates of analysis are available on request for the lot you receive. [CONFIRM: shipping timeframe and returns policy wording.]