Why is meth so bad? The devil made it. And because it messes with your dopamine and makes you a fiend. When you take Methamphetamine your brain releases large amounts of dopamine. The dopamine is then taken by receptors but there is excess dopamine in the synaptic gap. When the dopamine is being collected back up, the meth molecules are brought back along with excess dopamine. Meth works as an antagonist and takes up areas that dopamine should be picked up. When the excess dopamine is left in the synaptic cleft, your levels of dopamine drop sharply, rendering the user an addict for life in exaggerated terms.