Definition:

Dose: It refers to the amount of medicine or substance that must be taken at one time.

Dosage: It refers to how often and how long the medication must be taken.

When is Dose used?

Doses refer to measured portions of medicine or substances taken at a time. The frequency at which the drug should be taken is not mentioned.

When is Dosage used?

Dosage refers to when and how often the medicine is to be taken. An individual is instructed how many times and until when they must repeat their dose.

Examples for Dose & Dosage

Dose:  "The doctor prescribed a 7 mg dose of biotin." Dosage: "The doctor prescribed a dosage of 5 mg of biotin twice a day for two weeks."

Examples unique to Medical Writing

Incorrect: We noticed that a dosage of 10 mg amphetamine did wonders on the patient.  Correct: We noticed that a dose of 10 mg amphetamine did wonders on the patient.