Period leaks come down to three things: using a product that matches your flow, positioning it correctly, and having a backup layer on your heaviest days. Most leaks happen not because a product failed, but because it was the wrong absorbency, shifted out of place, or stayed in too long. Here’s how to fix each of those problems.
Match Your Product to Your Flow
The single biggest cause of leaks is using a product that can’t keep up with your bleeding. Products vary wildly in how much they hold. Regular tampons hold about 20 mL of blood, while heavy-absorbency tampons hold 31 to 34 mL. Menstrual cups range from 22 to 35 mL depending on size. Menstrual discs hold the most of any category, averaging 61 mL, with some models holding up to 80 mL.
If you’re soaking through a regular tampon in under two hours, switching to a heavy-absorbency tampon or a menstrual disc can make a real difference. Period underwear, by contrast, holds only about 2 mL on average and works better as a backup than a standalone product on heavy days. For reference, total blood loss above 80 mL per period is considered heavy menstrual bleeding, so if you’re regularly blowing through products, it’s worth tracking how fast you saturate them.
Check Your Cervix Height for Internal Products
If you use a menstrual cup and it leaks despite not being full, the cup may be the wrong size for your anatomy. The key measurement is your cervix height: the distance from your vaginal opening to the tip of your cervix. You can check this yourself by inserting a clean finger during your period and noting how far in you reach before touching the cervix.
A low cervix (about 44 mm or less, roughly one knuckle deep) means a standard-length cup may sit too low and not catch blood properly. A menstrual disc is often a better option here because its catch basin is shallow and it sits higher up, directly around the cervix. A medium cervix (45 to 55 mm, or about two knuckles) works well with most standard cups. A high cervix (above 55 mm) pairs best with longer cups that have a deeper catch basin, since a short cup may sit too far below the cervix and let blood flow past.
Get the Placement Right
A menstrual cup needs to fully open and seal against the vaginal walls to work. After inserting, run a finger around the base of the cup to check for dents or folds. If it hasn’t popped open, grip the base and rotate it, or gently push against the vaginal wall to let air in. A cup that’s only partially open will leak from the start.
Menstrual discs require a different technique. Pinch the disc in half, then insert it angled down and back toward your tailbone. Push it as far back as it will go so it sits in the vaginal fornix (the space around the cervix). Then tuck the front rim up behind your pubic bone. That front tuck is what holds the disc in place. If you feel it shifting, use a clean finger to push the rim further back and then pull the front edge up toward your belly button until it locks behind the bone.
For pads, placement matters too. Center the pad so it covers the area where blood actually lands, which for most people is slightly further back than you’d expect. If you tend to leak toward the back (especially at night), shift the pad an inch or so rearward.
Layer Your Protection on Heavy Days
On your heaviest days, typically days one through three, using two products at once is the most reliable leak prevention. A menstrual cup or disc paired with period underwear gives you both a primary catch and a backup. A tampon with a thin pad works too.
Interlabial pads are another option many people don’t know about. These are small, leaf-shaped pads that sit between the labia and catch blood right at the source before it reaches your underwear. They work especially well for sudden, heavy gushes and can be layered with a regular pad or period underwear for extra security. They don’t go inside the vaginal canal, just between the outer folds.
Compression shorts or tight-fitting sports underwear also help by keeping external products firmly pressed against the body, which prevents the shifting and bunching that causes gaps.
Prevent Leaks During Exercise
High-impact movement like running, jumping, or gymnastics creates two leak risks: products shifting from impact, and strong pelvic floor muscles squeezing a menstrual cup out of position. If you notice your cup leaking only during workouts, your pelvic floor contractions may be displacing it.
A menstrual disc can be more stable during exercise because it’s held in place by the pubic bone rather than relying on suction. Combining any internal product with compression shorts or period underwear gives you a safety net regardless of what happens. If you use pads during sports, check and change them at halftime or between sets rather than waiting for a full soak. Changing tampons every four to six hours during activity, or more often with heavy flow, prevents them from reaching capacity mid-workout.
Prevent Leaks While Sleeping
Nighttime leaks happen because you spend hours in one position and gravity pulls blood in directions your product doesn’t cover. Two adjustments help significantly.
Sleeping in the fetal position, on your side with your knees tucked toward your chest, relaxes your abdominal muscles and reduces the pressure that pushes blood out. It also keeps gravity from pulling blood straight backward toward your lower back, which is where most overnight leaks show up. If you sleep on your back, placing a small cushion or folded towel under your hips tilts your pelvis slightly and slows the downward flow.
For products, overnight pads with extra length in the back are designed for exactly this problem. Pairing one with period underwear creates a near-bulletproof setup. Menstrual cups and discs can be worn overnight since they’re safe for up to 12 hours, giving you coverage through a full night’s sleep. Tampons, however, should not be worn longer than 8 hours, per FDA guidelines, so set an alarm if you tend to sleep longer than that.
Change Products Before They’re Full
This sounds obvious, but most people wait until they feel a leak to change products rather than changing on a schedule. Tampons should be changed every 4 to 8 hours, and never left in longer than 8 hours. On your heaviest days, checking every 2 to 3 hours keeps you ahead of overflow.
Menstrual cups and discs give you more time, but on heavy days the cup may fill faster than you expect. If you’re new to a cup, empty it every 4 hours for the first couple of cycles until you learn your rhythm. Once you know how quickly you fill it, you can extend the intervals on lighter days.
Save Your Clothes When a Leak Happens
Even with the best setup, leaks happen. Acting fast makes the difference between a temporary stain and a permanent one. Rinse the fabric under cold water as soon as possible. Never use hot water on blood; heat sets the proteins and locks the stain in.
For fresh stains, soak the fabric in cold water with an enzyme-based detergent, which breaks down the hemoglobin in blood. For dried stains on light-colored clothing, dab hydrogen peroxide directly on the spot. A paste of baking soda and water also works well: spread it over the stain, let it sit for 15 to 30 minutes, then rinse. Keeping a small stain stick or a travel-size bottle of hydrogen peroxide in your bag gives you a quick fix when you’re away from home.