What is "vaginal ring"

n. A contraception device consisting of a flexible ring held in the vagina which provides a controlled release of drugs.

Vaginal rings (also known as intravaginal rings, or V-Rings) are polymeric drug delivery devices designed to provide controlled release of drugs for intravaginal administration over extended periods of time. The ring is inserted into the vagina and provides contraception protection. Leaving the ring in for three weeks slowly releases hormones into the body, mainly vaginally administered estrogens and/or progestogens (a group of hormones including progesterone). These hormones work mostly by stopping ovulation and thickening the cervical mucus, creating a barrier preventing sperm from fertilizing an egg. They could theoretically affect implantation but no evidence shows that they do. 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:

• Estring - a low-dose estradiol-releasing ring, manufactured from silicone elastomer, for the treatment of vaginal atrophy ( atrophic vaginitis).
• Femring - a low-dose estradiol-acetate releasing ring, manufactured from silicone elastomer, for the relief of hot flashes and vaginal atrophy associated with menopause.
• NuvaRing - a low-dose contraceptive vaginal ring, manufactured from poly(ethylene-co-vinyl acetate), and releasing etonogestrel (a progestin) ethinyl estradiol (an estrogen).
• Progering, containing progesterone as a sole ingredient, is available only in Chile and Peru.

A number of vaginal ring products are also in development.