A reusable cup still depended on a steady supply
A menstrual cup works by collecting menstrual fluid inside the body rather than absorbing it. To do that, it needs to hold its shape while remaining flexible enough to insert and remove. The early cup’s heavy latex provided that combination—but it also made rubber an essential production material, not a substitute that could easily be swapped out.
Wartime demand squeezed a niche product
During World War II, rubber was in short supply as governments and manufacturers prioritized it for wartime needs. That put a small consumer product in a difficult position: even though a cup could be reused, each one still had to be made from rubber. Reusability reduced the need to replace the product often; it did not protect its manufacture from shortages.
The vulnerability was especially sharp for a new menstrual product. A factory could not simply keep making the same design without the material it required, and a niche item had little leverage when rubber was being directed elsewhere. The shortage therefore threatened more than a particular batch of cups: it endangered the commercial foothold of a design that had only recently reached the market.
A material shortage became a design bottleneck
The episode shows how a product’s future can hinge on a seemingly ordinary ingredient. The cup’s reusable principle was not enough to secure its place; it also needed a dependable supply of a specialized material. In wartime, that supply could matter as much as the design itself.
