Why does meth glow under a blacklight?

Methamphetamine can glow under a blacklight due to the presence of certain chemical impurities or additives, such as phosphorescent compounds or specific reagents used in its synthesis. These substances may fluoresce when exposed to ultraviolet (UV) light, causing the drug to emit a visible glow. Additionally, the presence of certain dyes or coloring agents added to methamphetamine can also contribute to this effect.