Why I Finally Made the Switch to Period Underwear (and Why I Wish I'd Done It Sooner)

18 giugno 2026

NIXI Body The Carla Black Leakproof Knicker Heavy — worn lifestyle shot showing the high leg VPL-free design and seamless waistband on a model, demonstrating the flattering fit and discreet absorbent gusset

I want to talk about something that took me fifteen years to address properly: heavy periods. Not in a clinical way — I've had enough clinical conversations about it — but in the practical, daily-life way that most people with heavy periods know intimately. The planning. The carrying. The anxiety about leaks in situations where a leak would be particularly unwelcome. The environmental guilt about the volume of disposables going through the bin every month.

I'd been aware of period underwear for a few years. I'd been sceptical for most of that time — not about the concept, but about whether it could actually handle what I needed it to handle. My periods are heavy. The products I'd seen described as "heavy" absorbency often turned out to be optimistic about what that meant in practice. I'd been let down by products that promised more than they delivered often enough to be cautious.

Then I found the NIXI Body Carla, and the spec changed my mind.

What Made Me Look Again

NIXI Body The Carla Black Leakproof Knicker Heavy — lifestyle shot showing the high leg design worn naturally, demonstrating the VPL-free silhouette and comfortable everyday fit — The Carla in everyday wear — the high leg VPL-free design and seamless waistband are both visible here. It looks and feels like regular underwear, which is the point.

Two things made me look more seriously at the NIXI Body Carla Black Leakproof Knicker in Heavy. The first was the absorbency claim: holds up to 20ml, equivalent to four tampons. That's a specific, quantified number rather than a vague "heavy" label, and it's a number that actually corresponds to what a heavy period day looks like for me.

The second was the Endometriosis Foundation connection. The Carla was created in collaboration with The Endometriosis Foundation, and £1 from every pair sold goes directly to the charity. I have endometriosis. Finding a product that was designed with that community in mind — and that actively supports the organisation working on it — felt different from a standard purchase. It felt like the right place to spend the money.

The Design Details

NIXI Body Carla Black Leakproof Knicker — front product view showing the high leg cut, seamless waistband and the smooth black fabric with no visible panty line design — The front view — high leg cut, seamless waistband, VPL-free. Designed to be worn under anything without showing through.

I found it in the Women's Underpants collection and read the spec carefully before ordering. The four-layer absorbent gusset — cotton lining against the skin, absorbent middle layers, waterproof TPU backing — is the construction that makes the absorbency claim credible. Each layer has a specific job: comfort, absorption, and leak prevention. It's not a single layer of fabric doing everything; it's a system.

The side profile — the seamless waistband sits flat without digging in, which matters particularly for anyone living with scars or a stoma.

The seamless waistband was a detail I noticed specifically because of my endometriosis — abdominal sensitivity is real and elastic waistbands that dig in are genuinely uncomfortable on difficult days. The Carla's seamless waistband was designed with this in mind, and it shows. The VPL-free high leg design means it works under fitted clothing without showing through, which matters when you're already managing enough on a heavy day without adding wardrobe anxiety to the list.

NIXI Body Carla Leakproof Knicker — detail shot showing the absorbent gusset construction layers including the cotton lining, absorbent middle and waterproof TPU backing — The four-layer gusset construction — cotton lining for comfort, absorbent layers in the middle, waterproof TPU backing. Each layer has a specific job.

The sizing note — size down for the most comfortable fit — was useful. I ordered one size down from my usual and it was exactly right: secure without being tight, which is what you need from something you're relying on for leak protection.

First Use

NIXI Body Carla Black Leakproof Knicker — flat lay product shot showing the full knicker from above, displaying the high leg cut and seamless construction — The flat lay — the high leg cut and seamless construction are both clear here. No bulky seams, no visible gusset outline.

I wore the Carla on the heaviest day of my last cycle. I want to be specific about this because I think it matters: I wore it alone, without a tampon or pad as backup, for a full working day including a two-hour commute and a meeting I couldn't leave early.

It held. No leaks. No anxiety. No moment of checking or adjusting. I got home, changed, washed the knicker at 30 degrees as instructed, and hung it to dry. The next morning it was dry and ready to use again.

I sat with that for a moment. Fifteen years of managing heavy periods with disposables, and this was the first time I'd gone through a heavy day without thinking about it constantly.

Three Cycles On

NIXI Body Carla Black Leakproof Knicker — lifestyle shot showing the knicker worn in a relaxed setting, demonstrating the everyday comfort and natural fit of the period underwear — In everyday wear — the Carla is comfortable enough to forget you're wearing it, which is the highest compliment you can give period underwear.

I now own four pairs of the Carla. I use them across my cycle — the heavy days alone, the lighter days sometimes paired with a cup for extra security on particularly active days. The washing routine is simple and the knickers have held up through repeated cycles without any degradation of the absorbency or the fabric.

NIXI Body Carla Black Leakproof Knicker — back view showing the high leg cut from behind and the smooth fabric construction without visible seams — The back view — the high leg cut from behind, smooth and seamless. Nothing that shows through fitted clothing.

The environmental difference is real. I've calculated roughly how many disposables I was going through per cycle and the reduction is significant. That matters to me, and it's a benefit that compounds over time — the longer I use the Carla, the greater the cumulative reduction.

NIXI Body Carla Black Leakproof Knicker — product detail showing the nylon and elastane outer fabric and the seamless waistband construction designed for comfort with scars or stomas — The seamless waistband detail — designed specifically for comfort against sensitive skin, scars, or stomas. A thoughtful detail that makes a real difference.

The £1 per pair to The Endometriosis Foundation is a small thing in isolation, but across four pairs it's four pounds that went to an organisation doing important work. Across the thousands of people buying this product, it adds up to something meaningful.

What's Actually Changed

NIXI Body Carla Black Leakproof Knicker — lifestyle flat lay showing the knicker alongside care instructions, demonstrating the washable and reusable sustainable period product credentials — Washable, reusable, better for you and the planet — the care is simple and the environmental benefit compounds with every cycle.

My relationship with my cycle is different. That sounds significant and it is. The anxiety that used to accompany heavy days — the constant awareness, the planning, the checking — has reduced substantially. I still have endometriosis. My periods are still heavy. But the management of them is no longer the exhausting logistical exercise it used to be.

If you have heavy periods and you've been sceptical about whether period underwear can actually handle them, the NIXI Body Carla Black Leakproof Knicker in Heavy is the one that changed my mind. Find it in our Women's Underpants collection and browse the wider range in Lingerie and Clothing. It's also in Apparel & Accessories and our Latest Products if you're browsing what's new.

— Saoirse Hennessy-Doyle, freelance translator and endometriosis advocate, writing from a position of considerably less period-related anxiety than she had six months ago.