We get this question often in our shop – especially from tourists coming from warmer places!
Generally, having a cold is a physical discomfort that does not interfere with your psychedelic experience. The cold-relief medicines do not act on the brain, as psilocybin does.
That being said, a cold can be uncomfortable and any discomfort may affect your ‘set’ (I’m referring to ‘set and setting’) of the trip. We like to stress the importance of doing everything within your reach to get as comfortable as you can (including your surroundings: ‘setting’) before you take the truffles.
One last thing, and this is going to sound like your mother: don’t forget to dress for the cold when you go tripping outdoors!