Warning! These similar sounding words have very different meanings. To prescribe is to recommend and to proscribe is to forbid. One little letter makes a big difference.
Prescribe is the more common word, and it's often used at the doctor's office. When a doctor jots down a prescription, she prescribes a drug to heal the patient. To prescribe also means to recommend something in an official way. Here are some examples of the word used correctly:
"If physicians want to help their patients, they need to prescribe affordable versions of accepted medical interventions." (Forbes)
"We are not centralist to the point where we prescribe what they spend on player wages, transfer fees." (Washington Times)
Leave proscribe to the pros. Proscribe is a rare and more formal word, meaning to forbid something or to demand a stop to it. It's often used in the phrase "a proscribed organization," such as a terrorist group that an official has demanded an end to. Here are some other examples:
"In contrast, laws in some European nations proscribe and even criminalize various forms of 'hate speech.'" (Reuters)
"The Constitution proscribes government discrimination on the basis of race, and state-provided education is no exception." (Washington Post)
If you're tempted to get them mixed up, think of the "e" in "prescribe for me," and the "o" in "Oh no, don't for proscribe."