A woman i a pair of period-proof panty from Female Engineering with their logo.
Period-proof panty guide
Say hello to the future of period protection from Female Engineering. This spotless guide covers all the need-to-know for making the switch from tampons and liners to reusable period undies. Ready, set, flow!

Find your panty style

Whether you’re a brief or boxer kinda gal or a fan of the almost invisible – we got you covered. Literally. Find your fave fit, style, and get ready to flow freely.

A woman in a pair of black hiphugger period-proof panties.
Hiphugger
The ever-so-popular Hiphugger is a tried-and-true undie essential that offer equal parts comfort, protection, and support. A semi-low rise for no-show wear.
A woman in a pair of black High Waist period-proof panties.
High Waist
The sky is the limit with these high-waisted heroines. Always stretchy and never clingy, this style will ensure all-day comfort and style. Through your cycle and beyond.
A woman in a pair of black Thong period-proof panties.
Thong
For those days you need a little bit protection, but a whole lot of comfort. The Engineered Thong is unseen but powerful, because you deserve to period in style.
A woman in a pair of black Boxer period-proof panties.
Boxer
Meet the Boxer, the queen of comfort. This ready-to-wear classic will see you from the sheets to the streets, and keep you dry and protected all day long.
A woman in a pair of black Bikini period-proof panties.
Bikini
Our bikini is designed with a low waist and high cut leg, making them the perfect less coverage period panty.
A woman in a pair of black Brazilian period-proof panties.
Brazilian
Inspired by the beaches of Brazil, this high-performer will keep you worry-free and protected on your light flow days. Go cheeky and period in style with this well-loved favourite.
A woman in a pair of black Sleep period-proof panties.
Sleep
Sleep through a storm (or flood) with these powerful period panties. Enforced with our highest absorbency level, an extended gusset, and extra front-to-back coverage.
A pair of black Teen period-proof panties.
Teen
Empowering young minds with comfort and confidence from the first drop. With beginner-friendly protection that follows them from school, to gym class, and back home again.
A woman in a pair of black Maternity period-proof panties.
Maternity
While you’re patiently waiting, we´ll support you though life’s little (or heavy) leaks. With a soft belly-cover and integrated panels, for under-tummy and lower back support.

Find your absorbency level

Wondering how much protection you need? We got you covered from the first drop to the last, with absorbency level mini to super.

Absorbs up to 5 ml 1/2 tampon/1 panty liner

illustration of drops showing Mini that can absorb up to 5 ml of liquid.

Absorbs up to 10 ml 1 tampon/pad

illustration of drops showing Light that can absorb up to 10 ml of liquid

Absorbs up to 20 ml 2 tampons/pads

illustration of drops showing Medium that can absorb up to 20 ml of liquid.

Absorbs up to 30 ml 3 tampons/pads

illustration of drops showing Mid-High that can absorb up to 30 ml of liquid

Absorbs up to 40 ml 4 tampons/pads

illustration of drops showing High that can absorb up to 40 ml of liquid

Absorbs up to 50 ml 5 tampons/pads

illustration of drops showing Super that can absorb up to 50 ml of liquid

Find your waist rise

A woman in a pair of period panties with normal waist height.
Regular
Are you a fan of the classic mid-rise? Our regular waist hits right at the natural waistline and fits seamlessly under regular-cut bottoms. An everyday essential that always stays in place.

A woman in a pair of period panties with High waist.
High
Do you like to stay comfy while aiming high? Then our high-hipped fit might be for you. Cut just below the belly and with wide sides that don’t dig in, for all the comfort you deserve.
An illustration showing the different layers of a pair of period panties.
How do they work?
Period panties are much like regular underwear but with added functionality that absorbs menstruation blood, prevents leaks, controls odour, and wicks moisture. The secret is the Engineered Leak Tech™ - a patented technology consisting of three different layers working together to keep you dry, comfy and odour-free. Wear your period panties for up to 10 hours. Wash, dry, wear them again and again.

Our materials

Female Engineering’s period panties are made to be used again and again. This is why we design them with great attention to details. Like the material blends, all developed for a soft and barely-there feel. Here are some of the materials we use.

All the cotton we use at Female Engineering is organic, which means it is grown without genetically modified seeds, pesticides, or synthetic fertilisers. But that’s not all – most of our cotton is organic PIMA cotton. PIMA a premium cotton with longer and silkier fibres, making it incredibly smooth against the skin and stronger than conventional cotton.

Polyamide is known for its stretchy and durable features. We mostly use recycled polyamide, which is usually made from pre-consumer fabric waste, but can also come from post-consumer materials like industrial fishing nets.

We use recycled polyester for its stain-resistant and quick-drying features. Recycled polyester is usually made from plastic bottles, packaging, or textile waste.

Two women in period panties.
Size guide
Not sure of your size? Time to grab the old tape measure and get that unique body of yours measured up!
A pile of packs of period panties.
45-day trial offer
Being female should be hassle-free. That’s why we offer a 45-day free trial when you buy our period underwear for the first time. Simply buy it, try it, wear and wash it. If you're not satisfied, let us know and we’ll refund you fully.
A squatting woman in period panties with the Female Engineering logo.
About Female Engineering
We are a Swedish femtech brand with the goal of reinventing female freedom. We’re here to find solutions to women’s real needs, riding the wave of period consciousness straight into the mainstream.
Illustration of how to take care of your period panties. Rinse, wash, dry.
Period panty care guide

Your most common questions

Female Engineering® make period-proof underwear for all flow levels, from light to heavy bleeders. For those worried about bleeding more, we recommend starting out by wearing the period panty at home during a heavy bleeding day. That will put it to the test and make it easier to figure out how it works.​

Our period panties are made to last at least 50 washes, which is far above industry standards. The number of washes is determined by the gusset absorption layer in our Engineered Leak Tech™, which has an antibacterial and anti-odour treatment that tends to lose a little bit of effectiveness after 50 washes. It is likely that the function of the panty will last longer though, but 50 washes is what we can guarantee. However, the fabric, form and fit of the panty will last a lot longer. If a panty is worn and washed once per menstruation cycle, it will last around 4 years.​

Our period-proof underwear come in different absorbency levels, much like disposable menstrual products: 5 ml Mini ≈ ½ tampon/panty liner 10 ml Light ≈ 1 tampon/pad 20 ml Medium ≈ 2 tampons/pads 30 ml Mid-high ≈ 3 tampons/pads 40 ml High ≈ 4 tampons/ pads 50 ml Super ≈ 5 tampons/ pads

From heavy period to lighter days:

Based on light panty liner, normal size tampon and normal sized pad. This means that the Mid-high period panty for example has the capacity to hold up to 30 ml of blood, which is almost equal to the total amount of the average menstrual fluid loss per one whole period - which is 35 ml (but varying between 20 and 80 ml).