Estrone is a type of estrogen, which is a group of hormones important for sexual and reproductive development. It is primarily produced in the ovaries, but can also be made in fat tissue and the adrenal glands. Estrone plays a crucial role in regulating the menstrual cycle and maintaining reproductive health in females. In addition to its role in female physiology, estrone is also present in males, although in smaller amounts. It can be converted into other forms of estrogen, such as estradiol, which is the most potent form. Estrone levels can fluctuate throughout a person's life, particularly during menopause when ovarian production decreases.