South Korean femtech company Inertia has launched its Prism Pads in the U.S. The pads use a patented, plant-derived core designed to replace the synthetic superabsorbent polymers common in the category.
Inertia was founded in 2021 by female scientists from KAIST. The team noticed that most period care innovation focused on surface materials. The absorbent core inside stayed largely unchanged. So they built a new one.
The result is Labocell, a cellulose-derived polymer hydrogel matrix. Unlike conventional cores that rely on SAP particles or pulp structures, Labocell traps fluid within a crosslinked three-dimensional network. This lets it absorb efficiently without particulate SAP.
Most SAP materials were optimized for distilled water, not menstrual fluid, which behaves differently in viscosity and flow. Inertia says Labocell was engineered specifically around those conditions.
Cellulose-based absorbents have been explored before as SAP alternatives. Low gel strength and high material costs limited earlier attempts. Inertia’s research aimed to solve both problems while keeping the material manufacturable.
One challenge was avoiding clumping. Hydrogel materials can aggregate unevenly within a thin pad. Inertia addressed this by laminating Labocell with ECF pulp, creating a nonwoven-style sheet before it goes into the core.
The pads also use organic cotton nonwoven materials in the cover and wings, so the layers touching skin are natural fibers.
Inertia has already sold more than 10 million pads in South Korea. Prism Pads rank as the top feminine care product at Olive Young, the country’s largest health and beauty retailer.
The company sees rising U.S. interest in material transparency as a natural opening for expansion.
