Some databases allow you to limit to peer reviewed, but typically, publications self-report to vendors that they are peer reviewed.
It is the exception rather than the rule that dubious publications will claim peer reviewed status.
Google the journal title, head to their website and review the submission information. When an author submits an article for publication in this journal, what process will it undergo by those who review it? Look for:
double blind refereeing (neither the reviewer or author is identified to one another)
Do they name their editorial board? Who are they and what are their affiliations?
Google the author
What are his or her affiliations? (what university or laboratory do they work at? Who pays for their research?)
What else has he or she published?
Where else has he or she published?
Who has cited his or her work? (see Follow the Conversation tab at left)