system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are certain drugs (Ex: Methotrexate) better to take once a week and not daily?

Specifically for methotrexate, why is the dose six pills once a week and not a pill a day for six days of the week?
gpt
To allow a higher (efficacious) dose and then recovery from (horrible) side effects. In the case of methotrexate, it is highly toxic. You take it once and then spend a week recovering from the damage it has done before having another dose. There would not be enough time for recovery otherwise. This is the same reason some other chemotherapy drugs are taken intermittently too.