I recently learned about this consumer tip when I saw the following question in a newspaper or magazine:
Question: I hear if you are going to just buy alcohol or pharmacy you are let in (to Costco) even if you don't have membership. True?
Laws prohibit pharmacies and liquor stores from discriminating. If you want to sell to anyone it has to be available to everyone. Hence the no membership required for prescription drugs or alcohol.
I discovered that yes, you can use Costco's pharmacy as a non-member. However, you won't get the member's discount if you are a non-member. Costco offers most prescription and other medications at a pretty nice discount if you are a member.