{"id":104453,"date":"2026-08-12T09:33:53","date_gmt":"2026-08-12T07:33:53","guid":{"rendered":"https:\/\/sileu.com\/period-underwear-definitive-guide\/"},"modified":"2026-08-12T09:33:53","modified_gmt":"2026-08-12T07:33:53","slug":"period-underwear-definitive-guide","status":"publish","type":"post","link":"https:\/\/sileu.com\/en\/period-underwear-definitive-guide\/","title":{"rendered":"Period Underwear: The Definitive Guide (Layers, Absorbency and Washing)"},"content":{"rendered":"

Period underwear<\/strong> is the fastest-growing category in period care in Spain, and that’s no accident: it’s regular-looking underwear with invisible absorbent technology that replaces (or backs up) pads and tampons. In this guide we explain how the layers work, how to choose the right absorbency and size, how to wash them so they last for years, and when to combine them with a menstrual cup. With concrete facts, no inflated promises.<\/p>\n\n

What period underwear is and how it works<\/h2>\n

If you’ve made it this far, you’re probably considering the switch but a few reasonable doubts are holding you back: does it really absorb? Does it smell? How many pairs do I need? Is it worth the cost? Let’s answer them all, starting from the beginning.<\/p>\n

On the outside, it looks like regular underwear. On the inside, a four-layer system stitched into the gusset absorbs flow, locks it in, and prevents leaks and odor. The difference from a pad is night and day: nothing shifts, nothing rubs, nothing crinkles, and at the end of the day you wash it and reuse it for years.<\/p>\n

\"Diagram
The four layers of period underwear: drainage, absorption, waterproof barrier and outer fabric.<\/figcaption><\/figure>\n

The top layer wicks flow toward the absorbent core and stays dry to the touch; the core holds the equivalent of 2-3 tampons depending on the style; a breathable but waterproof membrane stops leaks; and the outer fabric is cotton, just like your everyday underwear. With Sileu period underwear<\/a>, the cotton is organic with OEKO-TEX Standard 100<\/strong> certification \u2014 the international textile seal that guarantees fabrics free from harmful substances, which matters for something that’s in contact with your skin for hours.<\/p>\n\n

Period underwear vs. pads: the honest comparison<\/h2>\n

The average person spends \u20ac5-10 a month on disposable pads or tampons. Period underwear at \u20ac9.99, which holds up through 2-3 years of washing, pays for itself within the first month or two. Add to that what you can’t measure in euros: sleeping without feeling like you’re “wearing something”, zero plastic in the trash, and zero disruptors in contact with your skin (more in our article on what pad and tampon marketing doesn’t tell you<\/a>).<\/p>\n

The weak point? With very heavy flow, underwear alone can fall short on the heaviest days. That’s where combining it with a cup comes in, which we cover below.<\/p>\n\n

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Sileu organic cotton period underwear \u2014 \u20ac9.99<\/strong><\/p>\n

Certified organic cotton (OEKO-TEX Standard 100), reusable, breathable and hypoallergenic. Pays for itself within the first month compared to disposable pads, shipped from Spain in 24-72h.<\/p>\n

See Sileu period underwear \u2192<\/strong><\/a><\/p>\n<\/div>\n\n

\"Sileu
The fabric: organic cotton with OEKO-TEX Standard 100 certification.<\/figcaption><\/figure>\n

How to choose absorbency based on your flow<\/h2>\n

The practical rule: think about what you’d use that day if you were wearing tampons.<\/p>\n