system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Does a medications half life continue to leave your body at the same rate after the half-life is reached?
gpt
For first-order elimination, half of it gets eliminated in the first half-life; another quarter gets eliminated in the second half-life; then an eight of it in the third half-life, then a sixteenth, and so on.  The "rate" in terms of the length of one half-life stays the same, but the "rate" in terms of milligrams per hour steadily goes down.

Some drugs (alcohol as the most well known) instead follow zero-order elimination, where a fixed amount of drug gets eliminated per hour.

You can also have hybrids between those two - For example, a first-order drug may saturate the path your body uses to eliminate it, and act like a zero-order drug until your levels drop below that upper limit.