Food-grade Vs Medical-grade silicone
One of the theories I had about the cheap Chinese cups, was that they could be made using cheaper silicone, perhaps food-grade, rather than medical-grade.
While most of the listings for the cups state they are medical grade, there are a few that say they are made from food-grade silicone. Which is a concern. If some of them are, then it is possible that others are. You are really only relying on what a product listing says to know what it is made from.
It could also explain why most of the cheap cups are also very soft/squishy. It could be because there are more softeners added, but it could be because they are made from different silicone.
For example, Blossom Cup’s website claims the cup is FDA approved (which is false), and that it is made from FDA approved medical grade silicone.
Yet their Amazon listing says the cup is made from Food-Grade silicone:
If it is made from food-grade silicone, then not only is their website fraudulent, but if the other similar cups (Charlene, Dutchess etc.) are in fact the same cups too (just rebranded), then those would all be food-grade not medical grade too… and those claim they are medical grade.
Another example is the cups being sold by Zhida Xintai, those list food grade silicone as their material.
What is the difference?
I really can’t say if food-grade silicone is going to be worse for a cup to be made from than medical grade. However something that is safe for contact with food, may not necessarily be safe for skin-contact inside your vagina for days.
Medical grade silicone is designed for products that are used inside the body, and it is therefore tested on animals. Now, while we might not like that fact, it is done to make sure that the material is safe to have in the body. Food-grade silicone does not undergo those tests, as it is designed to have contact with food only. Not for being used on or in the body.
So while food-grade silicone may be perfectly fine to use, there is no guarantee it won’t cause reactions, because it has not been tested for that use.