Can i get an allergic reaction from ritalin (methylphenidate)? my friend gave me one and i am taking an act tomorrow. i am allergic to tree nuts, cats and dogs.

Not likely: You are foolish to take somebody's pills. What in the world is "taking an act"?

It's both illegal &: a bad idea for a person without ADHD to take stimulant medication for the 1st time on the day of a 4 1/2- hour ACT + Writing Test. A low dose may have no positive effect, yet increase blood pressure & pulse & cause anxiety/agitation. Short-acting Ritalin (methylphenidate) wears off in 3 ½ - 4 hours & may cause you to "crash" before you finish the exam. Don't risk your academic future.

It is illegal: for your friend to give you any medication especially a controlled substance. They are practicing medicine without a licence and dealing drugs . It is dangerous to take a medication from another person. Consult your doctor or go to ER if you are having a reaction.