Masmi Reuse menstrual underwear for swimming UPF 50+ / chlorine‑resistant (size: XS, S, M, L)

Menstrual swim panties / pool menstrual panties function as menstrual underwear – worn during your period, they replace pads, tampons and other feminine hygiene products. They ensure your period doesn’t limit your physical activity or ruin your holiday plans! The absorbent insert of the menstrual bikini, which comes into contact with the intimate area, is made from the healthiest GOTS-certified organic cotton, grown without pesticides, herbicides or chemical fertilizers. The outer fabric of the bikini is resistant to chlorine and salt water – it has been tested for this purpose in accordance with ISO 105.

Why choose Masmi menstrual bikini swimwear?

• 100% GOTS-certified organic cotton in the 3D absorbent layer – means no irritation of the intimate area, no inflammation, fungal infections or chafing.
• Maximum absorbency (up to 77 g) – that’s more than 6 super-size tampons. It guarantees comfort and safety throughout a full day at the beach or pool. You don’t have to give up your plans!
• The bikini provides high UV protection at UPF 50+ helping to reduce the risk of sunburn, premature skin ageing and cancer.
• The outer fabric of the panties is resistant to chlorine and salt water – it has been tested for this purpose in accordance with ISO 105.
• Our swim panties don’t “rustle” when worn, because the absorbent layer contains no film (polyurethane, polyester, etc.) – 100% discretion and comfort in every situation.
• Guaranteed up to 100 washes without loss of absorbency! – We are the only brand on the market to offer such a guarantee on our swim bikini. If you follow the manufacturer’s washing instructions, Masmi swim briefs will retain their properties for up to 400 washes without losing absorbency!
• The 3D absorbent layer of the swim briefs prevents leaks, guaranteeing maximum safety and protection.
• They are an excellent solution for women with light urinary incontinence – you can still enjoy physical activity with complete freedom.
• They are planet-friendly – fully biodegradable, no component of the product has been tested on animals, and they contain no superabsorbents, film, plastics, artificial fragrances or allergenic ingredients.

This product is the bottom part of a swimsuit – you can choose any top you like to go with it.

Q&A:

• Do you use a pad or tampon together with menstrual swimwear?

Menstrual swim panties are designed to provide protection during menstruation on their own. There is no need to wear an additional pad or insert a tampon, but if you feel more comfortable, you may use extra protection.

• Is menstrual bikini underwear expensive?

Period swim briefs are highly efficient and durable, so buying them is definitely economical. They can last for 3–4 years without any loss of absorbency. If you follow the manufacturer’s washing and drying instructions, this period can be as long as 6 years (remember that the bikini can last even longer, but its absorbency will decrease slightly over time – this process will not be noticeable to you).

• Does a period bikini leak?

No, menstrual bikinis do not leak as long as they are used and cared for properly. However, you should monitor your body and adjust how long you wear them based on your period's intensity.

• Does menstrual bikini underwear smell bad?

An unpleasant odor may sometimes appear if you have an intimate infection.

• Can you feel the wetness of menstrual blood in your period bikini?

If menstrual bikini underwear is washed correctly, it does not lose absorbency and keeps up with absorbing blood into the absorbent layer.

• Does menstrual blood leak into the water when you swim in a pool or the sea?

No, menstrual blood does not leak into the water, and here is why this does not happen:

special construction and absorbent layers

Period bikinis (i.e. period panties in a swimming version) are made of special materials that:

• the absorbent layer retains blood and moisture inside the material,
• The outer layer is waterproof, which prevents leakage to the outside.

Therefore, menstrual blood is trapped in the inner layer and water from the outside does not penetrate inside.

physical phenomena

When you are submerged in water, hydrostatic pressure:

• hinders the flow of fluids from the vagina to the outside,
• it may temporarily reduce bleeding, because the pressure of the water on the body gently “pushes back” the flow of blood.

That’s why bleeding seems lighter under water

liquid surface tension

• Water: has a high surface tension (approximately 72 mN/m at 20°C) due to strong hydrogen bonds between water molecules, which leads to minimization of the surface area (e.g. droplet formation).
• Menstrual blood: its surface tension is lower than water’s due to the presence of proteins, lipids, and other surfactants in plasma and endometrial secretions, which reduce cohesive forces at the liquid-air interface. As a result, menstrual blood soaks into the surface of the absorbent pad more easily compared to water, which tends to form distinct droplets and is harder to absorb into the bikini/swimsuit pad.

well-fitting cut

Menstrual bikini underwear is designed to fit snugly to the body, especially around the groin and buttocks. This reduces:

• possibility of blood leaking out,
• water getting inside.

Blood does not flow freely underwater. It’s worth knowing that menstrual blood doesn’t “flow” continuously—it comes in waves or drops, often only when changing body position or during uterine contractions. During bathing, these factors are reduced, so less blood reaches the vaginal canal.

• Does the bikini soak up water while swimming?

Masmi bikini bottoms do not soak up water while swimming (or only minimally), because they are made from waterproof materials that prevent water from entering the absorbent layer from the outside.

• How does it work exactly?

outer layer – waterproof

This part is resistant to absorbing water because it is made of a waterproof material – it acts as a barrier that prevents water from getting inside.

absorbent layer – inner

Designed to absorb menstrual blood, not water. It works on the principle of capillary absorbency – but is shielded, so it does not come into direct contact with pool or sea water.

good fit

Adhering closely to the body (especially in the groin and around the buttocks) prevents water from being “pumped” inside during swimming or movement.

• Why do bikinis and period suits absorb blood but can be washed?

The answer lies in the special multi-layer construction of period swim underwear and the difference between water and menstrual blood.

The inner absorbent layer is made from organic cotton that absorbs fluids (e.g. blood, mucus). It is hidden under the outer layer, so it does not come into contact with water while swimming.

movement and pressure

During washing (by hand or in the machine), mechanical action breaks up structures (dirt, proteins, blood); the use of warm water and detergent, which reduce surface tension, allows the fabric to “absorb” again.

special absorbent properties

The absorbent layer has been designed to absorb thicker fluids (blood, mucus) for a long time.

designed to fit your body – available in 4 sizes: XS, S, M and L

How to wash and care for your period bikini?

1. Wash before first use.
2. After use, we recommend rinsing and/or allowing to soak before washing.
3. Can be hand or machine washed with the rest of your laundry or in a separate laundry bag (if you prefer).
4. If using a washing machine, wash at a temperature no higher than 40º.
5. For proper care, we recommend using neutral soaps. Avoid using chlorine, bleach, fabric softeners, natural oils, or Marseille soap, as they may affect absorption.
6. Do not tumble dry, as this may reduce absorbency.

We guarantee unchanged absorbency of our menstrual bikini swimsuit for up to 100 washes! When you follow the manufacturer’s washing and drying instructions, the Masmi menstrual bikini swimsuit will retain its properties for up to 400 washes!

composition:

outer layer: 80% recycled polyamide, 20% elastane

bottom layer: 82% recycled polyamide, 18% elastane

absorbent layer: 94% certified organic cotton, 6% PU

A hypoallergenic product with 4 certificates: GOTS, FSC, VEGAN and COTTON NATURAL.

in black

product suitable for vegans

made in Spain.

NOTE: SIZES OF MENSTRUAL UNDERWEAR MAY VARY SLIGHTLY DEPENDING ON THE SERIES, THEREFORE, IF YOUR MEASUREMENTS ARE BETWEEN TWO SIZES, E.G. S AND M, WE RECOMMEND CHOOSING THE SMALLER SIZE.

THE PRODUCT IS IN A CARDBOARD PACKAGING SECURELY SECURED WITH A STICKER. ONCE OPENED, FOR HYGIENE REASONS, RETURNS ARE NOT ACCEPTED.

Masmi and Silver Care products differ only in external packaging; the product itself is the same. If one type is unavailable in your order, the equivalent from the other brand will be sent.