I spent SEVEN hours watching people take Ayahuasca at a 'psychedelic church' in Utah and the sound of vomiting is still ringing in my ears - yet somehow I'm now tempted to try it

The ceremony is scarcely ten minutes in and one poor soul is already purging his demons into a bucket in front of him.

He convulses on the floor as the sound of his retching echoes throughout the three-story retreat in Hildale, southern Utah, and presumably the mountains beyond.

A tough-looking Russian man in line to see the shaman turns to his friend behind him and whispers: 'This is scary.'

We haven't even got to the Ayahuasca yet.

This is just the warm up: the administration of 'rapeh', or 'Shamanic Snuff', a tobacco used by indigenous Amazonian tribes for relaxation and healing.

A participant at a three-day Ayahuasca retreat in Hildale, Utah, gets some much needed rest on day two following an intense psychedelic trip the previous night, before he goes again 

A man plays guitar next to the 'altar' where a shaman will dole out servings of Ayahuasca tea during the evening ceremony, which lasts around seven hours

The retreat is run by Hummingbird Church, co-founded by Courtney Close (left), 44, a vice president at a US bank, and Colombian shaman Taita Pedro Davila (center). It is one of hundreds of 'psychedelic churches' to have sprung up across the US

Men and women recoil and splutter as the substance is blown up their nostrils. Some have tears rolling down their cheeks.

I'm asked if I'd like to try some. I'll get my relaxation some other way, thanks.

Observing an Ayahuasca ceremony while stone cold sober for seven hours is at various points intensely exhausting, soporifically dull and, occasionally, inexplicably therapeutic.

The one constant is the undulating sound of vomiting. It's still ringing in my ears.

I'm at a three-day retreat run by the Hummingbird Church, whose co-founder, Courtney Close, is a vice president at America's eighth largest bank. 

The gathering is part of a global boom in people turning to hallucinogenic drugs in search of spiritual enlightenment, including NFL star Aaron Rodgers, actor Will Smith and Prince Harry.

Taking Ayahuasca is still illegal in the US, so hundreds of 'psychedelic churches' like Hummingbird have sprung up across the country in the hope that labeling it as a divine act will mean their activities will be protected under religious freedom.

Some attendees freely admit this is simply a legal loophole, but one they believe is justified to allow them access to what they claim is the plant's therapeutic qualities.

There are around 40 participants at the $900 retreat in Hildale.

They are roughly divided in half by gender, but by various degrees in ages and backgrounds, including blue collar workers from Rust Belt States, Silicon Valley CEOs, nervous first-timers and hardened travelers.

A Hummingbird Church member blows 'rapeh', a tobacco snuff, up another's nose using a pipe called a 'tepi' to prepare them for an Ayahuasca ceremony it previously held in California

The retreat in Hildale, Utah, is a three-story building hired out to the church for Ayahuasca ceremonies several times a year

The retreat backs onto stunning views of the surrounding landscape near Zion National Park

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The Duke of Sussex spoke to 60 Minutes interviewer Anderson Cooper about his experiences drinking ayahuasca and taking other psychoactive drugs

The medicinal benefits of Ayahuasca have not been well studied, but everyone here believes it could help them fix a part of their lives, be it trauma, addiction, depression, or something else that is impossible to define.

US Marine Corps and Afghanistan veteran Dave Selby, 34, turned to Ayahuasca around 18 months ago.

'I don't know why I'm here,' he says. 'I just wanted to follow my heart.'

He does his best to explain what I am about to see - and what on earth it all means.

'The entirety of our existence is billions of people in the same reality having a different experience.

'This ceremony brings together people from all walks of life, from different countries, different states, from wonderful childhoods to terrible childhoods, to share space and work on whatever it is they need to work on.

'And that's why it's one of the most beautiful f****** things.

'It won't seem like that tonight, because it's going to be a bunch of people crying and throwing up in a bucket and, and people screaming or people snoring real loud, or making weird, random noises.

'But a lot of that, I would say, is the start of the discovery of finding their truth, right?'

Tonight's truth-seeking is to be conducted by Colombian shaman Taita Pedro Davila, who exudes an almost cult-like aura to his followers.

In the hours before the ceremony begins, he is spoken of in hushed whispers, but never seen.

One man tells me that, when he was a boy, Taita's father sent him away to the Amazon jungle to take Ayahuasca every day for three weeks in search of a higher plane.

No one knows what Taita will put in his brew tonight; how strong it will be, how long it will last.

Everyone will drink from the same tea, but in different quantities, as Taita sees fit. He will utter a single prayer over each cup before he hands it to you to drink, ushering the spirits to make the medicine - as it is referred to – work in individual ways.

For some, the tea will call them to confront their darkest fears in the most terrifying ways imaginable.

For others, it may bring a cosmic connection with mother nature of otherworldly beauty.

No one questions this. In Taita, they trust.

Tonight's theme is Jungle Love. But for now, the King of the Jungle sleeps.

We don't know when he will awake. He runs on 'Taita time'.

Paraphernalia is laid out in one of the rooms at the Hummingbird retreat in Hildale 

Participants speak of terrifying experiences in which they confront their darkest demons, before being transported into a world of 'unadulterated bliss'

I've arrived at 2pm (earthly time) on day two, meaning many of the participants are still sleeping off last night's trip, or have gone for a hike to clear their heads in the stunning surroundings of Zion National Park.

Kenny Darbyshire, 40, a construction worker from Iowa, who has just returned from FaceTiming his two young children, shares his experience from the night before - his first on Ayahuasca.

'I was getting visuals, mainly geometric triangles and colors moving.

'It was weird. I could kind of move it for a while.

'But then something happened. I opened my eyes and it took me right out of it. Like I was just back to normal, you know, and that's when I got sick again.'

Kenny is not here for kicks. He is here to fix himself.

'Something's broken inside me and I've tried to cover it up with substances and alcohol,' he says.

'I started doing drugs when I was about 12. I've been in treatment twice in the last two years with some success, but not much.

'Whatever I find through the next few ceremonies, maybe I can find a little piece of that answer and go home and continue to work on it.'

US Marine Corps and Afghanistan veteran Dave Shelby, 34, turned to Ayahuasca around 18 months ago because he no longer felt happy in his life. He has attended several Hummingbird ceremonies

For father-of-two Kenny Darbyshire, 40, a construction worker from Iowa, the retreat in Hildale was his first taste of Ayahuasca, which he is hoping will help him with his substance addiction following mixed results going in-and-out of treatment

Ex-Mormon Chris Walton, 44, thanks the group for supporting him while he 'went through hell' while tripping on Ayahuasca the night before

Shortly after 5pm, rumors abound that Taita is ready.

Everyone is called to the main assembly area, which consists of two large rooms dotted with mattresses and divided by an open doorway, separating men and women for the duration of the ceremony.

The first ritual is the administration of copal, a smoke made from tree sap that is blown all over the bodies of participants to balance their energies.

It will be used continuously throughout the night, which I am later grateful for, as it also masks the smell of sick.

Soon the lights go out and Taita descends. The room falls silent.

He is wearing a baseball cap, boar-tooth necklace and poncho.

Electric candle lights flicker as musicians strike up an ethereal tune. They are led by Eddie, a virtuoso handpan player, who is accompanied by a medley of ancient percussive instruments including an Aboriginal bullroarer, which consists of a piece of wood attached to a string that produces a rumbling vibration when swung.

The rapeh is administered and, after the 'purging' is over, Taita calls 'first cup'.

A single line forms and Taita hands the Ayahuasca tea out one-by-one, before participants return to their mattresses.

For 15 minutes or so there is calm, with Eddie's flickering handpans the only sound to be heard.

Then the vomiting starts up again, slowly building into a cacophony, a sickening symphony of its own.

Those who chuck up within half an hour of consuming their brew have to go back and receive their medicine again, for they have purged it too soon.

In total, three servings are administered throughout the night.

Everyone appears to be going through their own very personal journeys. One woman spends the entire night bent over double on her mattress, rocking back and forth.

Another appears to be struggling to breathe early on in proceedings and is tended to by sober facilitators.

While some groan and scream in intestinal anguish, others appear in total control - a young woman calmly jots down her thoughts in a journal.

A slight man next to my observation seat sits crossed legged for hours, staring straight ahead, barely moving.

I think he is some kind of zen maestro, before sometime after his second cup he suddenly falls to the floor and begins writhing uncontrollably.

I edge away, fearing he may be enduring some kind of psychotic episode, before he starts screaming 'Oh my God, it's so beautiful!'

It takes two male facilitators to restrain him and carry him down to the basement until his zen is restored. 

The ceremony has its own rhythms. There are periods, lasting up to around half an hour, where it seems the whole room is vomiting its soul.

There are times when the music takes over. At one point, everyone strikes up a rousing chorus of Let It Be to rapturous applause.

Very occasionally, there are moments of silence and contemplation, when Taita tells his musicians to stop playing and the room falls silent.

But it is not long before someone starts heaving or screaming again.

A Hummingbird Church facilitator embraces a worshipper after sharing their experiences from an Ayahuasca ceremony the night before in Cherry Valley, California

The following morning, everyone gathers together to share their experiences from the night before.

Some are moved to tears.

Chris Walton, 44, an ex-Mormon who is hoping Ayahuasca will help with his anger management, strikes a particularly poignant note.

'Last night was amazing,' he says. 'I drew so much enthusiasm and inspiration and power from everyone here.

'There is no private space here and everyone is going through things, some of it very challenging.

'It really helped me. I went through hell and had to confront my deepest fears. Subsequent to that, I was able to experience that pure unadulterated bliss.

'But I had to do the fear thing first. It's awesome you guys played a huge part in that for me. Thank you.'

Chris later asks me if I wanted to take Ayahuasca having watched its effects unfold in front of me.

Bizarrely, despite feeling for large parts of the night like I was sitting at the gates of hell, with its flames lapping at my feet in the form of splattering sick, I tell him 'maybe'.

It would have been a hard 'no' beforehand. 

But the controlled environment of Hummingbird Church, with experienced facilitators readily on hand to calm anyone who is losing their mind and stop them choking on their own vomit, is somewhat reassuring.

If it really can be transformative, and consumed responsibly, maybe it is worth a try.

Just don't hold me to that.