NuvaRing is a small, flexible vaginal ring that releases two hormones to prevent pregnancy. It works primarily by stopping ovulation, so there’s no egg available to be fertilized. With perfect use, it’s 99.7% effective; with typical use (accounting for real-life mistakes), about 92% of users avoid pregnancy in a given year.
How the Hormones Prevent Pregnancy
The ring continuously releases two hormones directly through the vaginal wall into your bloodstream: 120 micrograms per day of a progestin (a synthetic form of progesterone) and 15 micrograms per day of a synthetic estrogen. These are the same types of hormones found in combination birth control pills, just delivered differently.
Together, these hormones suppress the signals your brain sends to your ovaries each month to mature and release an egg. Without that signal, ovulation doesn’t happen, and pregnancy can’t occur. This is the primary way the ring works.
Two backup mechanisms add extra protection. The progestin thickens your cervical mucus, creating a barrier that makes it much harder for sperm to reach the uterus. It also thins the uterine lining, making it less hospitable if an egg were somehow fertilized. These layered effects are why the ring is so effective when used correctly.
The 21/7 Cycle
You insert the ring and leave it in place for three weeks (21 days), then remove it for one week (7 days). During that ring-free week, you’ll typically get a withdrawal bleed similar to a period. After the seven days are up, you insert a new ring and start the cycle over, regardless of whether your bleeding has stopped.
The ring doesn’t need to sit in any precise position inside the vagina. It just needs to stay in. The hormones absorb through the vaginal walls no matter where the ring rests, so there’s no “wrong” placement as long as it’s comfortable.
What Happens if the Ring Comes Out
The ring can occasionally slip out during tampon removal, intercourse, or a bowel movement. If it’s been out for less than three hours, rinse it with cool or lukewarm water and reinsert it. Your protection continues uninterrupted.
If the ring has been out for more than three hours, your protection drops. What you should do depends on where you are in your cycle:
- Weeks one or two: Rinse the ring and put it back in. Use condoms for the next seven days. If you had unprotected sex in the days before or during the gap, you may need emergency contraception.
- Week three: You have two options. You can insert a brand-new ring immediately and skip the ring-free week (you may not get a bleed but could have spotting). Or, if the ring was in continuously for at least seven days before it came out, you can skip the ring, take your seven-day break, and insert a new ring on schedule. Either way, use condoms until a ring has been in for seven consecutive days.
If You Leave the Ring in Too Long
Forgetting to remove it on day 21 isn’t an immediate crisis. If the ring stays in for up to 28 days total (seven extra days), remove it, take your normal ring-free week, and insert a new one on schedule. You’re still protected.
If it’s been in for more than 28 days, remove it and put a new ring in right away. Use condoms for the next seven days, because hormone levels may have dropped enough to allow ovulation.
Forgetting to insert a new ring after the break is riskier. If your ring-free interval stretches to nine days or more and you had unprotected sex during that time, you may need emergency contraception.
Tampons and Sex
Tampons don’t interfere with the ring’s effectiveness. Studies measuring hormone levels in the bloodstream found no difference whether or not a tampon was in place. If you use both, insert the ring first, and check that it doesn’t come out when you pull a tampon.
The ring can stay in during intercourse. About 90% of couples in clinical trials said the ring wasn’t a problem during sex. Some partners may feel it, but it doesn’t reduce effectiveness. If you prefer, you can remove it for up to three hours during sex without losing protection, as long as you rinse and reinsert it promptly.
Storage Before Use
NuvaRing contains hormones that degrade with heat. Pharmacies typically store rings refrigerated. Once you bring a ring home, it can be stored at room temperature for up to four months, but keeping it in the refrigerator extends its shelf life. Never use a ring past its expiration date.
Who Should Not Use NuvaRing
Because NuvaRing delivers the same class of hormones as combination birth control pills, it carries the same risks, particularly for blood clots. You should not use it if you smoke and are over 35. The combination of nicotine, estrogen, and age sharply increases the risk of serious cardiovascular events like deep vein thrombosis, stroke, and heart attack. That risk climbs with every cigarette.
NuvaRing is also not appropriate for people with a history of blood clots, stroke, coronary artery disease, or certain heart valve conditions. Uncontrolled high blood pressure, diabetes with vascular complications, migraines with aura (at any age), or any migraines in women over 35 are additional reasons to choose a different method. A current or past diagnosis of breast cancer, liver disease, or liver tumors also rules it out.
If you’re taking certain hepatitis C medications (specifically combinations containing ombitasvir, paritaprevir, and ritonavir), the ring can cause liver enzyme elevations and shouldn’t be used at the same time.
How It Compares to the Pill and Patch
NuvaRing, combination birth control pills, and the patch all share the same effectiveness numbers: 99.7% with perfect use, 92% with typical use. The difference is practical. The ring only requires attention twice a month (insertion and removal), while pills demand a daily routine and the patch needs weekly changes. For people who struggle with daily pill timing, the ring’s schedule can reduce the chance of user error, which is the main reason typical-use numbers lag behind perfect-use numbers for all three methods.
The ring also delivers a lower daily dose of estrogen (15 micrograms) than most combination pills, which typically contain 20 to 35 micrograms. This is possible because vaginal absorption is more direct than oral delivery, where hormones must pass through the digestive system and liver first.