Vaginal rings (also known as intravaginal rings, or V-Rings) are 'doughnut-shaped' polymeric drug delivery devices designed to provide controlled release of drugs to the vagina over extended periods of time. 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.
- 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 progesterone) ethinyl estradiol (an estrogen).
A number of vaginal ring products are also in development.
Methods of use
General - Vaginal rings are easily inserted and removed. Vaginal walls hold them in place. Although their exact location within the vagina is not critical for clinical efficacy, rings commonly reside next to the cervix. Rings are typically left in place during intercourse, and most couples report no interference or discomfort. In many cases, neither partner feels the presence of the ring.  Rings can be removed prior to intercourse, but in the case of the contraceptive Nuvaring only for one to three hours in order to maintain efficacy of birth control.
- Femring - Femring is inserted into the vagina and left in place for three months, after which it is removed and replaced with a fresh ring.
- Nuvaring - Nuvaring is inserted into the vagina and left in place for three weeks, after which it is removed for a 'ring-free' week to allow menstruation to occur.
Vaginal ring updates
Vaginal ring technology is currently being developed for the controlled release of microbicides and vaccines for the prevention of HIV infection.
Issues have been raised about the biodegradability of the product given the recent concern about pollution and use of plastics, especially of the poly(ethylene-co-vinyl+) archetypes.