Histrelin is a hormone similar to one normally released from the hypothalamus gland in the brain. Histrelin works by decreasing the amount of estrogen and testosterone in the blood. Suppressing estrogen can cause thinning of the bones or slowing of their growth. Histrelin acetate is a potent LHRH agonist which stimulates LH and FSH release and inhibits the actions of sex steroids on the male and female reproductive tracts. After a transient increase， continuous administration results in down regulation of LH and FSH levels followed by a suppression of ovarian and testicular steroid biosynthesis. Histrelin potency in vivo and in vitro is similar to that of the D-Trp6-containing analog. Especially because of its high water solubility and greater lipophilic character， it appears promising for clinical application. Histrelin has a molecular formula of C66H86N18O12， a.a. sequence of Pyr-His-Trp-Ser-Tyr-D-His（Bzl）-Leu-Arg-Pro-NHEt and having a Mw of 1323.32 Dalton.
Lyophilized Histrelin although stable at room temperature for 3 weeks， should be stored desiccated below -18℃. Upon reconstitution Histrelin should be stored at 4℃ between 2-7 days and for future use below -18℃. For long term storage it is recommended to add a carrier protein （0.1% HSA or BSA）.
Please prevent freeze-thaw cycles.