Another treatment, typically used when other options have failed, is injection of a gonadotropin-releasing hormone agonist. These drugs create a temporary, drug-induced menopause-like condition. Addback of estradiol is recommended to prevent bone loss long-term; this generally necessitates the concurrent addback of progesterone to prevent estradiol-induced endometrial hyperplasia. Two landmark studies have demonstrated that the addback of estradiol or progesterone on top of GnRH agonists can cause a resurgence of PMDD symptoms but that this resurgence of symptoms remits after one month of stable addback.