Q. Are all PubMed articles peer reviewed/scholarly?

A good percentage of material on PubMed is scholarly and may even be peer-reviewed.

You can verify that the journal your article is in practices the peer review process by running a search in Ulrich's, a database, using the title of the journal in which your article was published.

The list of titles appears in a chart with rows and columns. Locate the row containing the journal your article is in and look to see if there is a "referee shirt" in one of the columns to the left. Hovering over the symbol, it tells you the journal practices peer review.