N-acetylcysteine (NAC), an over-the-counter supplement that reduces hair pulling and skin picking

N-acetylcysteine (NAC) is the most effective substance known to science to help stop hair pulling (trichotillomania). NAC is an amino acid that modulates the amount of the neurotransmitter glutamate in the brain. It is also an antioxidant. A 12-week placebo controlled double-blind study published in 2009 in the Archives of General Psychiatry showed that 56%…