When u take shrooms what causes the psycodelic trip?

Psilocybin: This is the active compound in psychedelic mushrooms the cause the "trip". It goes to the brain and has its effect. It affects certain receptors in the brain such as serotonin receptors. Serotonin and its receptors play an important role in mood, thus drugs like "shrooms" can often have unpredictable effects.

Psilocybin : Psilocin has a high affinity for the 5-ht2a serotonin receptor in the brain, where it mimics the effects of serotonin (5-hydroxytryptamine, or 5-ht). The serotonin system is involved in the control of behavioral, perceptual, and regulatory systems, including mood, hunger, body temperature, sexual behavior, muscle control, and sensory perception. Psilocybin causes intense activation of these.

HALLUCINATIONS: Biochemistry. Be careful you don't exacerbate an underlying condition in your brain that would provoke more hallucinations even when not eating mushrooms.