Alarelin

Also known as GnRH-A, LHRH-A

A potent, synthetic GnRH agonist used in research to investigate pituitary-gonadal axis function and the effects of sustained GnRHR activation.

Length: 9 amino acids
Half-life: More stable than native GnRH; specific in vitro value not well characterised
Mechanism: Alarelin is a synthetic agonist of the gonadotropin-releasing hormone receptor (GnRHR) with enhanced potency and stability compared to native GnRH.
Studied in: It is used in reproductive biology and endocrinology research to study the regulation of pituitary gonadotropin (LH and FSH) secretion and the effects of continuous GnRHR stimulation.

About Alarelin

Alarelin is a synthetic nonapeptide analogue of gonadotropin-releasing hormone (GnRH). It features two key amino acid substitutions: D-Alanine replaces Glycine at position 6 (D-Ala6), and the C-terminal Glycinamide is replaced by an ethylamide group (Pro9-NEt). These modifications make the peptide significantly more resistant to enzymatic degradation and increase its binding affinity for the GnRH receptor (GnRHR).

Upon binding to the GnRHR in pituitary gonadotrophs, alarelin initially causes a potent release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). However, continuous or prolonged exposure leads to receptor downregulation and desensitization, ultimately suppressing gonadotropin release. This dual action makes alarelin a useful tool in research for both acute stimulation studies and for creating experimental models of suppressed gonadal function. It is a reference compound with a history of clinical use in veterinary medicine.

Laboratory notes

The substitution at position 6 is a common strategy in GnRH analogues to prevent cleavage by endopeptidases.
The biphasic effect (initial stimulation followed by suppression) is a critical characteristic to consider in experimental design and data interpretation.
Alarelin is more potent than native GnRH, requiring lower concentrations to achieve maximal receptor stimulation in vitro.

Storage and reconstitution basics: storage guide.

Questions about Alarelin

How does Alarelin's structure differ from native GnRH?

It has two substitutions: D-Ala at position 6 instead of Gly, and a C-terminal ethylamide modification. These changes increase its stability and potency.

What is the effect of prolonged Alarelin exposure on pituitary cells?

While initial exposure causes a surge in LH and FSH release, prolonged exposure leads to GnRH receptor downregulation and a profound suppression of gonadotropin secretion.

What is the primary research use of Alarelin?

It is used to study the regulation of the pituitary-gonadal axis, either by providing a potent stimulatory signal or by inducing a state of functional suppression for further investigation.

Is Alarelin for human use?

No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.

Related research peptides

All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.