Yes, you have to be very careul though as experiencing a niacin flush for the first time while tripping doesn't sound like a pleasant suprise. Taking a moderate 50-100mg dose of Niacin along-side a low dose of aspirin after a meal right before a trip may be a good idea. The aspirin is supposed to stop the red hot flushing feeling while keeping the vasodilation still in tact. I would not recommend other NSAID's as they are often vasoconstrictors unlike aspirin.
Not to mention, aspirin is also helpfull for it's abilities to stabalize temperature fluctuation which may occur during a trip.
Also, magnesium can work wonder for vasoconstriction/muscle tightness. Magnesium oxide has such a low bioavailability that it is not worth getting at all. Chelated forms are most prefferable with citrate being the second best form. Some people may get gas or diarreah from magnesium supplemenation so being near a toilet may be a good idea.
I recommend using all of these supplements without any other drugs before deciding whether or not to add them to your trips, to see how they effect you. Above all of this, staying hydrated and being well rested before a trip is always of importance.
