Well what give me skin rash and tingling is for the huge part niacin and arginin which also create a vasoconstriction (blood pumping like feeling*)
I can't discuss it much here but once i was in need of increased unnatural stamina ,all those intense training, work, daily life chores were taking their toll etc... so i took something and let's just say that in less than 15 minutes i used to have red skin and skin rash lol that was something
I always combo beta alanin with citrulin malate , cordyceps and tumeric if your aim is huge endurance ,also as stated it's useless to take huge amount of product since it's a load supplement , you would be wasting product.