How Much Blood Do You Actually Lose on Your Period? This Waterproof Liner Leak-Proofs Even the Heaviest of Flows!

Why does swimming on your period feel like such a hassle? Until now, none of the menstrual products have felt like they really work well in the water.

Which is why we're genuinely thrilled to introduce something that, shockingly, has never existed before: The V Seal, a waterproof intimate liner. A transparent, second-skin barrier that seals over your vulvar area so water can't get in, and nothing can get out. Protection without insertion. Comfort without compromise.

And yes — one of the first questions we hear is the big one:

"Will this waterproof liner actually keep my period from leaking, even if I have a heavy flow?"

Great question. Let's talk about the science — starting with a truth that might genuinely surprise you.

How Much Blood Do You Actually Lose During Your Period?

Most women massively overestimate how much they bleed each month. It makes sense — when you're dealing with cramps, stained underwear, and the relentless rotation of pads and tampons, it feels like a lot.

But the actual numbers are smaller than you'd think, and easy to visualize.

The average woman loses between 30–80 ml of menstrual fluid per cycle. To put that in everyday terms:

• 30 ml is approximately 2 tablespoons
• 80 ml is approximately 5–6 tablespoons

So across your entire period — all 3 to 7 days — most women lose somewhere between 2 and 6 tablespoons of menstrual fluid total. That's less than half a cup. Less than a shot glass on the light end.

Lighter flows may come in under 20 ml (just over 1 tablespoon) for the whole cycle. Heavier flows can reach 80 ml or above — and bleeding consistently above 80 ml per cycle is medically defined as heavy menstrual bleeding (menorrhagia), worth discussing with your doctor.

The takeaway: even on a heavy cycle, we're talking about tablespoons — not floods.

How Much Do You Actually Bleed in a 2-Hour Window?

Here's where it gets really relevant for swimming.

On your heaviest flow day, the average woman loses roughly 10–15 ml total for that entire day — that's less than 1 tablespoon. Spread across 24 hours, a 2-hour window represents roughly 1–2 ml of menstrual fluid. For heavier bleeders, that number might be closer to 3–5 ml during a peak 2-hour window on the heaviest day of the cycle.

To visualize that: 3–5 ml is less than one teaspoon.

No imagine that amount coming out into The V Seal while you're swimming. It's definitely not going to rupture the seal.

Even for women with heavier flows, the volume of blood produced during a single swim session is a small fraction of a teaspoon. The V Seal is more than capable of handling that — comfortably and confidently.

Why Other Period Products Fall Short in the Water

Let's be honest about what the current options actually put us through.

Tampons are the most common go-to for swimming on your period. But here's the problem: tampons are designed to absorb — and in water, they absorb everything, including water, bacteria, and chlorine. A waterlogged tampon loses its effectiveness fast. Worse, tampons sit directly against the most absorbent tissue in your body, the vaginal mucosa, which means whatever the tampon soaks up can get absorbed into your system. Chlorine, disinfection byproducts, bacteria — all held close. And when you climb out of the pool? That saturated tampon can drip. Not exactly the exit you were hoping for.

Menstrual cups are wonderful products — but not without risk in an active water environment. A cup's seal depends on correct placement, and vigorous movement, water pressure changes, or simply an off day with insertion can lead to an unexpected and very visible situation. Not to mention the mess upon removal, not everyone wants to troubleshoot suction mechanics poolside.

And beyond the practicality: not everyone wants to use an insertable product at all. Whether it's personal preference, anatomy, age, or stage of life — that's a completely valid choice, and it's one the market has largely ignored.

Swimming on Your Period, Sealed and Stress-Free

The V Seal is a transparent, ultra-thin waterproof liner that adheres gently to your skin, creating a physical barrier between your body and the water. It moves with you. It's designed to be virtually undetectable under a swimsuit. And it works whether you're doing laps, jumping waves, or floating in a lazy river with a drink in your hand.

Here's what that actually means for your period:

• You're in the water for 1–2 hours max per session
• Even on your heaviest day, your body produces less than a teaspoon of menstrual fluid in that window
• The V Seal's barrier means that fluid isn't going to leak — and water stays out

No more sitting on the edge while everyone else jumps in. No more wearing dark swimsuit bottoms and mentally calculating when you last changed your tampon. No more skipping the hot tub, avoiding the beach day, or quietly dreading the swim portion of a trip you paid good money for.

Your period doesn't get to veto your summer anymore.

The V Seal is hypoallergenic and comes with our V Happy Guarantee — love it, or your money back. It's the solution that should have existed a long time ago. We're just glad it's finally here.