The Most Addictive Over the Counter Drugs

6. Pseudoephedrine

Sold as a nasal and sinus decongestant, this drug is meant to relieve users from allergies, a cold, or the flu. When taken in order to experience a high, this drug can create stimulant effects. Since this stimulant is similar to amphetamines, some seek this drug in order to produce illegal methamphetamine. When abused, serious side effects can occur, including irregular heartbeats and when combined with narcotics, paranoid psychosis.