Before using your panties, wash them in the washing machine. This is necessary to activate the absorbency of the panties (full activation may require washing them up to 3 times). We recommend machine washing at 40 °C with a spin cycle of 1 000 rpm. Use a liquid detergent suitable for wool. To protect the merino wool, wash the panties inside a laundry bag for delicate items. Do not use fabric softener, as it will reduce absorbency and may damage the membrane. After wearing, rinse the panties in cold water. You can use a wool-friendly soap (lanolin, olive, or Marseille), but avoid cosmetic soaps, bile soaps, or deer tallow soap. If there is dried blood, soak the panties for 10–15 minutes to soften it. Gently press the crotch area, do not rub the fabric together. Do not twist or wring the panties; instead, carefully press out excess water. With proper care, the merino wool will stay soft for a long time and resist pilling. Then, machine wash at 40 °C and dry the panties inside out. Avoid drying on a radiator or in direct sunlight. You don’t need to machine wash them immediately after use; simply rinse by hand, let them dry inside out, and wash with your regular laundry later.

Our panties fully replace pads, tampons, or menstrual cups. We offer models with high and maximum absorbency. The absorbent layer in these models contains bamboo viscose (bamboo can absorb up to four times more moisture than cotton), making them suitable even for heavier flow. They also work perfectly as a backup to a menstrual cup or tampon.

Our merino wool is so soft that it doesn’t itch at all. The fiber thickness is 16.5 microns, which makes the knit feel silky and gentle to the touch.

The panties do not develop odors during use. Merino wool naturally binds harmful substances, including bacteria and microbes, helping to prevent odors. Bamboo has similar properties. That’s why we don’t need to add any chemical substances to the panties to control odor.

You won’t experience chafing in our panties. Merino wool has natural thermoregulating and breathable properties. The bamboo viscose knit shares these same qualities. The SAYUtech membrane, developed at the Technical University of Liberec, provides exceptional breathability.

We designed the membrane with this aspect in mind. The membrane itself is completely silent, but some natural rustling can occur when it comes into contact with other materials. From our experience, you might hear a slight rustle in a very quiet room, but only if you’re wearing the panties alone. Once you put on a skirt or pants, no sound is noticeable, especially since other clothing and shoes naturally make similar noises.

Our wool comes from Australian “mulesing-free” sheep. It is then processed by an Austrian company. Not only the final product is tested but the entire production process is monitored from start to finish. Factors considered include consumer safety, water and air pollution, workplace health and safety, and efficient use of resources. The wool is knitted and dyed by a Czech company with Oeko-Tex® Standard 100, Class II certification (for garments that come into direct contact with the skin).

Yes, you definitely can. It’s best to rinse the panties first, then machine wash them with your regular laundry using a liquid detergent suitable for wool. Set the spin cycle to a maximum of 1,000 rpm. Following this method will keep both the wool and the membrane safe and intact.

Use a liquid detergent designed for wool when washing the panties (ideally an eco-friendly one that is gentle on both your underwear and the environment). For hand rinsing, cold water works best, and you can use a wool-friendly soap such as lanolin or Marseille soap. Avoid using bile soap, deer tallow soap, shampoo, or any cosmetic or liquid soaps.

Wool is a protein-based fiber that naturally inhibits the growth and breakdown of microorganisms. Bamboo has similar properties. For this reason, both materials used in our panties are naturally antibacterial. Additional disinfection is not necessary and is actually unnecessary. Using a natural disinfectant is only recommended in the case of recovering from a serious gynecological infection (we suggest the disinfecting rinse from the brand Ulrich).

The materials we’ve chosen are of very high quality. During testing, the membrane withstood 30 wash cycles without any damage, but its actual lifespan is much longer. Within our SAYU team, we put the panties through intensive and frequent washing. Even after 100 wash cycles, the lace and elastic remain intact and retain their color. The membrane stays fully functional, and the wool remains soft and pleasant to the touch. If you follow our washing instructions and handle the merino wool pad gently when hand-washing, your panties will look like new for a very long time.

In general, you can wear the panties for 8 to 12 hours without any health risk. Of course, the exact duration is very individual. It depends not only on the flow of your period, but also on the consistency of your blood and, of course, your anatomy. You’ll quickly learn which models suit you best and how long you can comfortably wear them. If your flow is heavier, you may need to change the panties several times during the day. We also offer special waterproof pouches that make changing easier. For overnight use, our sleep models are ideal, since they are among our most absorbent, and customer reviews show that you can truly rely on them.

You can find size charts in the description of each product by clicking on “SIZE CHART.” Below the charts, you’ll find detailed instructions on how to take your measurements correctly.

If you’re unsure about which size to choose, don’t hesitate to contact us, we’ll be happy to help. The panties should never dig in; they need to fit comfortably. The materials we use are very stretchy and high quality. The elastic bands don’t stretch out from washing; they may shrink slightly at first but will relax again with wear. For low-rise models, the hip measurement is most important. For high-waist models, consider both the waist and hip measurements. Classic-cut panties can be worn low or pulled up to the waist; their waistband is wider than the high-waist model. When choosing this style, focus on the hip measurement. Classic-cut panties are ideal for all body types.

The inner pad of the panties is black, and the panties also feature a waterproof membrane, so you don’t need to worry about staining. If blood does happen to get on the lighter parts of the panties, it can be easily removed with a wool-friendly soap (use lanolin or Marseille soap). This method has been tried and tested.

We try to avoid unnecessary dyeing in our panties, so the absorbent layer and membrane are kept in their natural color. This is gentle both on the environment and on you. Only the outer parts of the panties are dyed, which makes washing and care easier. Even with minimal dye, the panties still look great.

We are a Czech company, and you can view and try our panties in person at our Prague showroom:

SaYu s.r.o.
Za Poříčskou bránou 390/18
Prague 8 – Karlín
Czech Republic

(Please visit during our opening hours.)

We ship within 3 business days of receiving your order. Once your package is sent, you’ll receive a tracking number to follow its progress.

Yes! Thanks to MeinEinkauf.ch, we can send our panties to Switzerland. MeinEinkauf.ch handles customs clearance and delivers the package directly to your home. The service costs 17.90 CHF plus a 20% surcharge on the value of the goods. To use this service, switch to our German website at www.sayustore.de using the option in the top-right corner of the page. You can find more information about MeinEinkauf.ch here. .