In brief
- A US team surveyed adults nationwide regarding health issues they attribute to psilocybin, LSD, MDMA, ibogaine, and 5-MeO-DMT.
- Among those who had taken MDMA, approximately 12% reported physical or mental deterioration, and 27% stated they had sought medical services as a result.
- This is a cross-sectional, self-reported study: it describes perceptions, does not demonstrate cause and effect, and does not distinguish by severity.
We know quite a bit about what happens with MDMA in a clinical trial, with screening, support, and controlled doses. We know significantly less about what happens outside that framework. A new study published in JAMA Network Open attempts to approach that reality by asking the population directly.
A national survey, not a trial
The team, led by Otto Simonsson and Peter Hendricks, analyzed the 2025 edition of the National Survey Investigating Hallucinogenic Trends, an online panel of adults from all 50 US states. The responses were weighted so that the sample reflected the country’s demographics.
The sample included 1,151 people with recent psilocybin use, 376 with LSD, 539 with MDMA, 74 with ibogaine, and 95 with 5-MeO-DMT. Everyone was asked if they had noticed adverse effects they attributed to the substance, if their physical or mental health had worsened, and if they had used medical services for that reason.
What the numbers say
In the case of MDMA, about 11.9% noted a worsening of their physical health, and 11.4% reported a decline in their mental health. Some 27.1% claimed to have used medical services that they attributed to their consumption. Seventy-two percent of those who had taken MDMA in the last year had combined it with other substances. Across the study, anxiety, fear, or panic were among the most frequently reported symptoms.
Comparison with the others is useful. Psilocybin stood at 6.2% (physical), 4.7% (mental), and 16.2% (medical services). LSD moved in figures similar to those of MDMA: 13.5%, 10.8%, and 27.3%. Ibogaine and 5-MeO-DMT were far higher: between 30% and 45% reported deterioration, and between 64% and 74% sought medical services, though these involved smaller sample sizes.
What it implies
It is best to read these numbers with caution. The authors emphasize that the cross-sectional design prevents drawing conclusions about causality, and that the attribution is made by each individual: substances with more intense or harder-to-ignore effects, such as ibogaine, may be blamed for distress where other factors also play a role. The work also does not separate mild from severe cases, meaning a sleepless night and a visit to the emergency room may count equally in some categories.
Even so, the value of the study lies in the fact that it offers a snapshot outside the laboratory, where MDMA use is mixed with alcohol, other drugs, and contexts without purity or dosage control. The authors conclude that the data support safety monitoring in the general population, harm reduction where needed, and balanced public communication regarding benefits and risks.
For those who want to delve deeper, we have a guide on MDMA and empathogens and another on harm reduction and responsible use, which explains how to test substances, space out doses, and avoid problematic combinations.
Source
- Simonsson O, Bradley M, Black JC, Rockhill KM, Monte AA, Hendricks PS. Adverse Health Outcomes of Psilocybin, LSD, MDMA, Ibogaine, and 5-MeO-DMT. JAMA Network Open, September 1, 2026 (DOI 10.1001/jamanetworkopen.2026.36756).
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
