It’s an FDA-approved. The initial letter of the acronym FDA (the F) has a vowel sound (eff). Since the rule for using "a" or "an" is based on pronunciation, not spelling, we use "an".

It’s an FDA-approved. The initial letter of the acronym FDA (F) has a vowel sound (eff). Since the rule for using a or an is based on pronunciation, not spelling, we use an.

It includes an FDA-approved drug label, which describes the drug’s benefits and risks.

It includes a FDA-approved drug label, which describes the drug’s benefits and risks.

Another example:

An FDA approval for a medicine means that the agency has decided that its benefits outweigh the risks.

Follow the same practice with other similar phrases that contain the abbreviation FDA (US Food and Drug Administration), such as an FDA advisory committee, an FDA inspector, an FDA regulation, an FDA investigation, etc.

She was accepted as a member of an FDA advisory committee.

Typically, an FDA inspector follows standard operating procedures.

Similarly, we say an F, an FYI email, an FBI agent, etc.

My daughter got an F on her exam.