<p>I heard for many professional schools like Med, Pharm, Opt they want a certain # of LOR from science professors. I was wondering if I have to take their class for the LOR to count because I heard from some people that the prof who you ask for a LOR had to give you a letter grade in a class. Is this true? I want a LOR from my professor who is in charge of the lab I work in, but I will probably not take his class since I can't fit anymore classes into my schedule if I want to graduate in time with a double degree.</p>