When is LH concentration highest in the menstrual cycle?

Luteinizing hormone (LH) plays a crucial role in the menstrual cycle, particularly in ovulation. Its concentration is highest just before ovulation, which is known as the LH surge. This surge is triggered by rising levels of estrogen that occur as the follicles mature during the follicular phase of the cycle.

As estrogen levels peak, they exert positive feedback on the anterior pituitary gland, leading to a significant increase in the secretion of LH. This spike in LH signals the ovary to release the mature egg, which is the key event in ovulation. Following this surge, LH levels drop, and they are lower during menstruation and the follicular phase. After ovulation, while LH levels do rise again, they do not reach the peak levels observed just before ovulation. This understanding of the hormonal dynamics is critical for grasping reproductive cycles and is fundamental for topics related to endocrinology in the MCAT.