Cetrorelix 5mg

Cetrorelix is a synthetic decapeptide that functions as a gonadotropin-releasing hormone antagonist (GnRH antagonist). This means it works by blocking the effects of gonadotropin-releasing hormone (GnRH), which controls the release of luteinizing hormone and follicle-stimulating hormone from the pituitary gland.

In medical practice, Cetrorelix is primarily used in assisted reproduction. It is administered to prevent premature ovulation in women undergoing controlled ovarian hyperstimulation, which is often a part of in vitro fertilization procedures. By preventing premature ovulation, Cetrorelix increases the chances of collecting mature eggs that can be fertilized and implanted.

Cetrorelix is usually given by subcutaneous injection under the supervision of a healthcare professional. A doctor should determine its use and dosage based on the patient's needs and condition.

Cetrorelix Peptide Structure

Peptide Sequence: Ac-3-(2-naphthyl)-D-Ala-4-Chloro-D-Phe-3(3-pyridyl)-D-Ala-Ser-Tyr-D-Cit-Leu-Arg-Pro-D-Ala-NH2
Molecular Formula: C₇₀H₉₂ClN₁₇O₁₄
Molecular Weight: 1431.0 g/mol
PubChem CID: 25074887

Benefits of Cetrorelix

Cetrorelix offers several benefits, particularly in the context of fertility treatments:

Prevents Premature Ovulation: Cetrorelix works by blocking the release of luteinizing hormone (LH), preventing eggs from being released too early from the ovaries. This gives the eggs more time to grow and mature, increasing the chances of successful fertilization and pregnancy.

Potent and Long-lasting: Cetrorelix is an extremely potent and long-lasting gonadotropin-releasing hormone antagonist. It blocks gonadotropins and sex steroid secretion immediately after administration, making it a reliable option for ovarian stimulation.

No "Flare Phase": Unlike earlier medications used to prevent premature ovulation, Cetrorelix does not have a "flare phase." This means the medication starts suppression immediately, without initially stimulating the hormones it is designed to suppress.

Improved Superovulation: Studies have shown that Cetrorelix can improve the effect of superovulation in aged mice without reducing oocyte (egg) quality, suggesting that it may offer similar benefits in humans.

Simple Stimulation and Shorter Stimulation Period: Clinical use of Cetrorelix has shown benefits such as simple stimulation, no increase of gonadotropin dose at GnRH antagonist initiation, avoidance of Ovarian Hyperstimulation Syndrome (OHSS) and ovarian cysts, and shorter stimulation period.

Absorption

Cetrotide is quickly absorbed when administered via subcutaneous injection, with peak plasma concentrations typically reached within one to two hours post-administration. In healthy female subjects, the average absolute bioavailability of Cetrotide after subcutaneous injection is approximately 85%.

How Does Cetrorelix Work?

Cetrorelix works by blocking the action of Gonadotropin-Releasing Hormone (GnRH) on its receptor. GnRH is a hormone that is released by the hypothalamus in the brain. It acts on receptors in the pituitary gland to stimulate the production and release of two other hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). They are essential for the growth and development of eggs in the ovaries.

In a normal menstrual cycle, a surge of LH (often referred to as the 'LH surge') triggers ovulation, which is the release of a mature egg from the ovary. However, in women undergoing assisted reproductive techniques like in-vitro fertilization, premature ovulation can lead to the loss of the developing eggs before they can be collected.

By blocking the action of GnRH, Cetrorelix prevents the production and release of LH and FSH from the pituitary gland. This effectively prevents the LH surge, thereby preventing premature ovulation. This allows doctors to carefully control the timing of ovulation to coincide with the collection of eggs, increasing the chances of successful fertilization and pregnancy.