Most chemicals used in meth production fall into three categories: solvents, metals/salts, and strong acids/bases. Methamphetamine mimics the effects of adrenaline but lasts much longer, causing euphoria, energy, and heightened arousal when inhaled. Extended meth use leads to addiction and "tweaking," with severe health effects including psychosis, violence, and cardiac issues. Signs of meth abuse include "meth mouth" due to dry mouth and teeth grinding, and skin sores from obsessive picking caused by hallucinations.