Myths vs evidence

Ketamine is used in veterinary medicine, but it was developed for people. It has been a human anaesthetic since 1970 and is on the World Health Organization's List of Essential Medicines.¹³

In an early randomised trial, a single dose improved symptoms within about two hours, and the difference from placebo lasted around a week.² For most people, one dose isn't a lasting fix. Research now focuses on repeated treatment, maintenance, and combining ketamine with therapy.

In monitored clinical settings, trials report mostly short-lived side effects such as dissociation and raised blood pressure. Frequent, high-dose non-medical use is linked to serious bladder damage,¹¹ and regulators require supervised use partly because of the potential for misuse.¹⁴ The setting and supervision matter.

Esketamine (Spravato) is the approved nasal spray, studied in phase 3 trials. IV ketamine for depression uses generic ketamine off-label. It has strong research of its own, but a different regulatory status.⁹ See our ketamine guide.

In two phase 3 trials of people with active suicidal thoughts, esketamine improved depression faster than placebo. But the difference on the suicidality measure itself wasn't statistically significant.⁶⁷ No trial has shown it reduces suicide deaths.

Trials are promising, but psilocybin isn't approved in Canada or the US. In the 233-person trial, the benefit of a single dose was clear at three weeks but not sustained at 12 weeks.² Against the antidepressant escitalopram, psilocybin didn't show a significant difference on the main measure.¹

Classic psychedelics like psilocybin are generally not considered to cause dependence or addiction.¹⁰ That doesn't make them risk-free: the main risks are psychological, and trials screen people carefully.¹¹

Psilocybin remains a Schedule III controlled substance.¹² Since 2022, doctors can request it for individual patients with serious conditions through Health Canada's Special Access Program, case by case.¹³ Dispensaries selling mushrooms are not legal.

In August 2024, the FDA declined to approve MDMA-assisted therapy for PTSD and recommended an additional phase 3 trial.⁴ It is not approved in Canada either. Australia is the main exception, where authorised psychiatrists can prescribe it.⁷

In the phase 3 trials, participants received a measured dose of pure MDMA in a supervised session. This sat inside a structured program of three preparation sessions and nine integration sessions.¹ Street ecstasy often contains other substances, and unsupervised use carries different risks.

Regulators raised specific concerns: participants could often tell whether they got MDMA (functional unblinding), questions about how safety data were collected, and cardiovascular risks.⁴ Separately, three papers based on the earlier phase 2 trials were retracted in 2024 over protocol violations at one site.⁵

A 198-person randomised trial of LSD for generalized anxiety disorder was published in JAMA in 2025.¹ It received FDA Breakthrough Therapy designation in 2024, and phase 3 trials are under way.⁵

In modern trials with screened participants, side effects were mostly short-lived and limited to the dosing day.² The real psychological risks, such as frightening experiences and possible lasting problems in people prone to psychosis, are why trials screen and supervise carefully.⁷

Small observational studies report reduced withdrawal and drug use after one treatment. In one, 50% of participants reported no opioid use at one month.³ But there are no randomised controlled trials, and many participants weren't followed up. It's a promising lead, not a proven cure.

Ibogaine can cause dangerous heart-rhythm problems.⁴ A review found 19 known deaths within hours to days of taking it. Most involved existing heart conditions or other drugs.⁵ Clinics outside North America vary widely in screening and medical monitoring.

Ibogaine isn't listed under the Controlled Drugs and Substances Act. But since 2017 it has been on Health Canada's Prescription Drug List, added because of serious and fatal adverse reactions. No ibogaine product is authorised for sale in Canada.⁶

DMT occurs naturally in the body in tiny amounts, but there's no direct evidence in humans that it floods the brain at death. This is a popular hypothesis, not an established finding.⁴

The vine in ayahuasca contains MAO-inhibiting compounds, which can interact seriously with other drugs, including many antidepressants.⁶ In a survey of more than 10,000 people, 2.3% needed medical attention after use.⁵

They're related tryptamines, but they act differently. 5-MeO-DMT has its highest affinity for the 5-HT1A serotonin receptor. It tends to produce fewer visual effects and higher rates of ego dissolution than classic psychedelics.⁷

Its effects are brief but extremely intense. Some people later experience sudden 'reactivations', a re-experiencing of the drug's effects days or weeks afterwards, which is less common with other psychedelics.¹¹⁸

There's no evidence toad secretion works better than the pure compound. It varies in strength, contains other substances, and demand for it is linked to poaching of the Sonoran Desert toad.¹⁶ The medicines in trials use synthetic 5-MeO-DMT.

In a head-to-head trial in healthy volunteers, a 500 mg dose of mescaline produced effects comparable to 100 µg of LSD and 20 mg of psilocybin.¹ Its effects also last longer, up to about 14 hours at high doses.²

A study of 61 Navajo members of the Native American Church who regularly used peyote in ceremonies found no psychological or cognitive deficits compared with people who used little or no substances.³ The authors caution that this may not apply to non-religious use.