Luteinizing Hormone (LH), also known as lutropin, is an endogenous glycoprotein hormone produced by the anterior pituitary gland. It belongs to the category of pituitary and trophic hormones and is crucial for normal reproductive function. Synthetic forms, such as lutropin alfa, have been developed for clinical use, particularly in the treatment of fertility disorders. LH is structurally similar to human chorionic gonadotropin (hCG), sharing a common receptor but differing in their physiological roles and timing of expression. LH plays a central role in regulating the reproductive system by stimulating the production of sex steroids in the gonads. Researchers have observed its involvement in follicular development in females and testosterone production in males. Beyond its reproductive functions, LH has been implicated in cognitive processes and neurodegenerative diseases, such as Alzheimer's, through its action in the central nervous system. The mechanism of action for LH involves binding to the luteinizing hormone/choriogonadotropin receptor (LHCGR), which activates downstream signaling pathways, including the cAMP pathway, leading to steroidogenesis and other cellular responses. Pharmacokinetic properties of LH vary depending on its form. Endogenous LH has a pulsatile release pattern, while recombinant forms like lutropin alfa have specific half-lives depending on the administration route. Clinically, LH and its analogs are used in assisted reproductive technologies and are generally well-tolerated. Regulatory approval varies by region, with recombinant forms like lutropin alfa approved for specific indications in fertility treatments.