How do i get rid of this rash i got from a pill?

OK, 2 days ago i took a pill my friend gave me for energy boost or excitement boost, and later that night when i went to bed i took off my clothes and found like 40 red rash dots that are like flat with no head on it. the rash or w.e it is, is located on the side of my stomach from like barely below my waste to my armpit on each side. im really worried. im not allergic to any food. and i hope this isnt anything serious. also ive had shingles a while ago but it cleared up if thats to any significants