![]()
出典:Wikipedia
出典:『Wikipedia』 (2011/07/07 03:58 UTC 版)
Vaginal rings (also known as intravaginal rings, or V-Rings) are polymeric drug delivery devices designed to provide controlled release of drugs to the vagina over extended periods of time. The ring is inserted into the vagina and provides contraception protection. Leaving the ring in for 3 weeks slowly releases oestrogen and progesterone hormones into the body. These hormones stop ovulation and thicken the cervical mucus, creating a barrier preventing sperms from fertilizing an egg. Worn continuously for three weeks followed by a week off, each vaginal ring provides one month of birth control. Several vaginal ring products are currently available, including: