Ferrocaine is a crude but effective street synthesis of a dissociative analgesic compound, believed to be derived from a degraded ketamine analogue base cut with a synthetic opioid receptor partial agonist. It's cooked in Shelf labs from sourced industrial precursors and sold in small crystalline capsules stamped with a crude iron cross. It works — it suppresses pain effectively — but the synthesis is inconsistent and every batch is slightly different. Shelf medics know it well because they see what it does when a batch goes wrong.