Shaminism

I was first introduced to shamanism last semester in professor Hass Religious studies class. I thought it was a joke then and i think it's a joke now. Shamanism sounds like a person goes into deep meditation and then can apparently go through three worlds. My question is do the Shamans take any sort of drugs before they get into this transitive state? In regards to Hughes, I just cant believe people actually buy into this, now i can believe shamans can go into a deep trasitive state and in their mind look for truth, but people that buy into Shaminism actually think Shamans can spirtually step out of their body and go speak to spirits. Not only does this go against all laws of physics, but the only way i feel to get over an ailment is to take medication that has been approved by the FDA and has scientific proof that it actually works.
In Walsh he talks about "The Opening of the Western Mind" this is exactly what i was talking about in the previous paragraph. Walsh states that psychedelics were used to get into these altered states. A pandoras box if you will of highs and lows, Shaminism is not a practice of medicine that opens up the human mind beyond all imagination,It's getting high. Im sorry if my opinion offends anybody, but between Hughes, Walsh, and what i learned last semester about Shaminism its a joke. I say if your sick go to a medical doctor that has the tools and the resources such as medicine and machines to find a virus or bacteria that is making you sick.