Why a Shipping Cushion Can Become a Moisture Trap
A pill bottle is opened and closed in changing conditions: each time the cap comes off, room air enters, carrying water vapor. Cotton is porous, so it does not seal that vapor out. Instead, its fibers can take up moisture and keep it near the tablets, where some medicines may gradually absorb it.
That matters because a tablet’s shape and performance depend on its ingredients staying stable. Moisture can soften or swell a tablet, make it crumble, or alter how it breaks apart after swallowing. The risk depends on the medicine and its packaging; cotton does not automatically ruin every pill, but it is not a substitute for a moisture-control system.
What to Do After Opening
The cotton’s job is largely finished once the bottle reaches you. Removing it avoids leaving a moisture-holding bundle among the tablets. Then close the cap firmly after each use and keep the bottle in the storage conditions listed on its label. A desiccant packet—the small packet designed to absorb moisture—is different from cotton and should generally stay in the bottle if the label says not to remove it.
A bottle that has absorbed moisture may offer no obvious warning beyond tablets that look or feel changed. That is why the simple shift from shipping protection to home storage matters: the packing material that cushions pills in transit need not remain in the bottle afterward.
