Breathwork is incredibly powerful.
People who have experienced shamanic or holotropic breathwork, rebirthing or other modalities using conscious connected breath for prolonged periods of time (45 mins +) have had experienced likened to plant ceremony experiences, as if they entered a psychoactive state of consciousness.
We are pretty incredible beings, capable of entering some odd states of consciousness indeed. Breathwork is a tool which can access different dimensions of human experience, the mind and beyond. With the power of the breath, some journeys may replicate a psychedelic experience as the body and mind undergo transformation. Other times, there is a very subtle and grounded experience during the session and one session can have different phases also. In short, you never know exactly what will happen; however, you can trust that your body and mind will go through the experience necessary for alchemy and evolution if there is trust and acceptance.