LHanaloger

LHanaloger, or LH analogs, are substances that mimic the biological activity of luteinizing hormone (LH) by binding to and activating the LH receptor (LHCGR). They can be natural or synthetic and are used to study LH-mediated signaling as well as in clinical settings where LH action is needed.

LH is a glycoprotein hormone composed of alpha and beta subunits. LH analogs aim to reproduce its receptor-binding and downstream effects, though differences in molecular structure, glycosylation, and pharmacokinetics can affect potency, duration of action, and tissue responses. Clinically important LH analogs include recombinant LH products (lutropin alfa) and recombinant human chorionic gonadotropin (hCG; choriogonadotropin alfa), the latter often acting as an LH surrogate due to its ability to activate the LH receptor.

In reproductive medicine, LH analogs are used to support or trigger ovulation in assisted reproductive technology (ART) protocols, especially when endogenous LH levels are insufficient or users require precise LH activity in combination with follicle-stimulating hormone (FSH). They may be employed alongside GnRH agonists or antagonists to optimize follicular development and luteinization. LH analogs also have indications in men with hypogonadotropic hypogonadism, where they stimulate testosterone production by the testes when paired with FSH or during testosterone replacement strategies.

Beyond clinics, LH analogs are used in research to investigate LH receptor signaling, receptor affinity, and downstream pathways. Availability is regulated as prescription medicines, with brand-name and biosimilar products varying by region. Potential adverse effects are similar to other gonadotropin therapies and include injection-site reactions and, in fertility contexts, risks associated with stimulation procedures.