system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 how do patches release medication (pain meds or birth control)

I used a birth control patch in high school. One of my coworkers was prescribed a patch for pain medication. How does it work?
gpt
The patches contain a spongy material that is coated in both your medication, and a chemical that allows it to penetrate through your skin into your blood vessels. By varying the kind of chemicals involved, their relative quantity, and the material of the patch, pharmaceutical scientists can get things to absorb at specific rates.