Prince Harry has said that marijuana "really helped him" mentally but taking cocaine "did nothing for him".
The Duke of Sussex opened up about his drug use in a live question and answer session tonight, set up to promote his memoir, Spare, where the audience paid for a ticket to tune in.
Speaking about cocaine, Prince Harry told Dr Gabor Maté: "That didn't do anything for me. It was more of a social thing."
He added: "It gave me a sense of belonging for sure.
"It also made me feel different to the way I was feeling, which is kind of the point."
Moving on to cannabis, which he has admitted to using before, Harry said: "Marijuana is different, that actually did really help me."
The Duke sat down with Dr Gabor Maté, an expert in trauma and childhood development, on Saturday March 4.to discuss living with loss and the importance of personal healing.
The live event came a month after the highly-anticipated book, which details how the young Prince dealt with the death of his mum Princess Diana, was released.
He also revealed he felt a lot of peer pressure to drink alcohol.
The Prince said: "I was at a dinner party and people would all be drinking and I wasn't the one drinking. I would feel left out of the conversation, to the point where it was like 'if you're not going to have a drink leave.' So i was like 'Okay I'll leave.'
"I started to realise 'Wow is this the way the world is'.
"Where if, for whatever reason you don't drink or you don't want to have a drink that night, then there seems to be this group peer pressure."
The duke also told of using psychedelics such as ayahuasca.
He went on: "It was the cleaning of the windscreen, cleaning of the windshield, the removal of life's filters just as much as on Instagram, these layers of filters.
"It removed it all for me and brought me a sense of relaxation, release, comfort, a lightness that I managed to hold on to for a period of time.
"I started doing it recreationally and then started to realise how good it was for me, I would say it is one of the fundamental parts of my life that changed me and helped me deal with the traumas and pains of the past."
Tickets for the event cost £17, plus a £2.12 fee for UK customers, and included a copy of Spare which became the fastest-selling non-fiction book in the UK since records began following its release in January.
Harry's ghost-written tell-all autobiography laid bare his frustrations with his family.
He claimed his brother William, now the Prince of Wales, had knocked him to the floor at Harry's then home Nottingham Cottage after calling the Duchess of Sussex "difficult", "rude" and "abrasive".
The duke claimed his father, now the King, put his own interests above Harry's and was jealous of Meghan and Kate, and that the Queen Consort sacrificed him on "her personal PR altar".
Speaking about negative reaction to the book, Harry said: "Sometimes I'm surprised and sometimes I'm not.
"It is the same group of people who react the same way when someone in a position like myself talk about their trauma.
"As we've already discussed, I'm not a victim in this, but there's almost a balancing act. The more they criticise, the more they comment, the more I feel the need to share.
"I found a way to be able to look around, and firstly ignore, the criticisms and the abuse."
The duke, who lives in California after moving to the US in 2020, has revealed he has enough material for two books but held back because he does not think his father and brother would "ever forgive" him.
It has not yet been confirmed whether Harry will be invited to attend his father's coronation in May.
The livestreamed event was produced by Penguin Random House in partnership with Barnes & Noble, Waterstones and Indigo Books & Music.
