Are Period Underwear Up to the Challenge of a Heavy Flow?

November 14, 2024
Team Knix / PERIOD UNDERWEAR

If you’ve got a heavier flow, you may know what it’s like to worry about leaks: Never knowing the ease of wearing an insertable (like a tampon or a cup) without a backup pad. (Or a backup backup pad). 

Having a period means at some point experiencing leaks—they’re totally normal and happen to everyone. They may happen more often if you experience heavier periods, though.

We wouldn’t blame you if you’d never considered period panties an option, assuming they just weren’t a match for you. But even if you’ve been doubling up on pads since your pre-teen years, we’re pretty sure it’s worth giving period panties a try.

Let’s get into what a heavy flow is, why it can be tough to manage, and whether period underwear is up to the task.

What’s Considered a Heavy Flow?

Let’s get technical for a second. According to the CDC, a “heavy period” is one that lasts more than seven days, requires a new tampon or pad every two hours or less, or involves passing large clots (ugh, the worst) the size of a quarter or bigger.

You might also have heavy menstrual bleeding if you soak through a pad or tampon every hour, need to double up on pads, or have to change your pad or tampon multiple times at night. 

Other signs of heavy menstrual bleeding include constant lower abdominal pain throughout your period, feeling super tired or fatigued, or experiencing shortness of breath due to blood loss.

About 1 in every 5 American women experience any or all of the above symptoms, meaning it’s super common to meet the medical definition of a heavy flow. 

But even if you don’t fit into any of these categories, you might still have heavier days, sudden episodes of “flooding,” or a period that feels heavy to you. 

The Struggles of Managing Heavy Periods

Heavy periods can interfere with just about every daily activity, from work to school to the gym. Leakage worries aside, it’s not exactly easy to focus—or move—when you’re cramping up and passing heavy clots. 

If you have heavy periods, you’ve probably tried to manage them in different ways. Maybe you’ve used two pads at a time, used a cup or tampon plus a pad, or even worn shorts under thick sweatpants just in case. It likely took you a while to find the right combination of products to help you feel comfortable. 

Or maybe you can’t always find the products you need, especially when you’re traveling. Sometimes you have to visit 3 or 4 different drug stores until you find the right ultra-heavy tampons, or you have to settle for a backup option you know won’t hold up.

Whatever the case may be, part of what sucks most about heavy periods is not always having the products you need on hand. That’s where reusable, period underwear could come in handy—but will they really work for you?

How Do Period Underwear Actually Work?

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Knix Super and Ultra Leakproof Underwear are designed with multi-layer technology to absorb even the heaviest periods. Magic layers of technical fabric in the gusset absorb and trap flow, while the top layer in the liner helps keep moisture away from the skin. 

Several styles also have an extra-long gusset and/or extra-secure edges for additional coverage and leak-prevention in the front, back, and sides. That means a lot less worrying about staining the crotch of your pants or that horrible drip down your butt when you lie down.

Knix products have five different levels of absorbency, from Lightest to Ultra Leakproof absorbency, and offer different styles for different absorbency levels. Super and Ultra Leakproof options are the most absorbent and best suited for heavier flow days if being used solo and not as backup.

Super Leakproof styles can absorb about 3-6 super tampons’ worth of menstrual flow, while Ultra Leakproof styles can handle about 7-9 super tampons.

That said, if you’re still concerned about leakage, or you’d prefer to use your period panties with a cup or tampon, you can always choose a lighter absorbency style and wear it as a backup with your insertable.

Why You’ll Love Period Underwear (Even on Heavy Days)

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All of Knix period underwear styles are designed to be comfy, smooth, and never bulky or bunchy. That means that, even with a heavy flow, you’re never walking around feeling like you’re wearing a diaper. Choose the right style for your clothes, and you also won’t have to worry about see-through leggings.

But the way we see it, maybe the biggest advantage to Leakproof period underwear is that they’re a more sustainable, lower-waste option. Think of all those tampons, pads, or disposable menstrual discs you won’t be throwing out every month.

And when you use period underwear, you’re not just being gentler on the planet—you’re also easing the strain on your wallet. While the upfront cost of period underwear might be a little bit higher, you save tons of cash on period products in the long run.

Add everything up and you’re looking at fewer trips to the bathroom, less single-use waste, and a huge cost savings. All of that, plus you get even more leak protection than you would with conventional period products.

Pro Tips for Using Period Underwear With a Heavy Flow

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To make the most of your period underwear, you still might want to double up on super heavy  days. For example, you could use a menstrual cup plus a pair of period undies for an extra sense of security.

It might also pay to use two period products for very busy days or long stretches without a bathroom. For instance, doubling up can give you peace of mind during back-to-back meetings at work. If you’re a big adventurer, double up on long car trips or hikes, so you don’t get stuck changing period products by the side of the road or in the woods.

After heavy flow days, your period underwear might need a bit of extra love and care to stay in tip-top shape. For best results, rinse them in cold water before tossing them in the washing machine. Wash them on cold with mild detergent and lay them flat to dry to make sure they stay good as new!

The Verdict: Are Period Underwear Right for Heavy Flow?

Period underwear can be a game-changer for folks with heavy flows: they can save you time, discomfort and major bucks. That said, it might take a little bit of trial and error to find the right styles or combinations of products for your body.

Try experimenting with different cuts and absorbencies, and don’t be discouraged if you need a little extra help. Meet with a Knix Product Expert if you need help deciding on the right period underwear for you.