Evidence by molecule
How strong the research is for each treatment, on our four-level evidence scale. Each links to the full molecule guide.
A 30-person trial found six infusions over two weeks improved PTSD symptoms more than an active placebo. Among those who responded, benefits lasted a median of about four weeks. Larger trials are needed.
Two phase 3 randomised trials (90 and 104 people) found larger symptom reductions with MDMA plus therapy than with placebo plus the same therapy. In 2024, the FDA declined to approve it and asked for another phase 3 trial.
What the research shows
MDMA-assisted therapy has the most advanced evidence for PTSD. Two phase 3 trials, with 90 and 104 people, found that MDMA combined with a structured course of therapy reduced PTSD symptoms more than the same therapy with a placebo.12 In August 2024, however, the FDA declined to approve it, citing concerns about functional unblinding, cardiovascular risk and how safety data were collected, and asked for another phase 3 trial.3 See our MDMA guide.
Ketamine has smaller trials. In one, 30 people with chronic PTSD who received six infusions over two weeks improved more than those given an active placebo. Among those who responded, benefits lasted a median of about four weeks.4 See our ketamine guide.
Ibogaine has been studied in 30 special operations veterans with traumatic brain injury. After treatment, PTSD symptoms were much lower, but there was no control group, and ibogaine carries serious heart risks.5 See our ibogaine guide.
Established treatments
Trauma-focused psychotherapies and some medicines have good evidence for PTSD. The treatments on this page are being studied mainly for people who haven’t been helped enough by these options. Talk to a qualified health professional about your own situation.
Studies in the library
- Review: psychedelic treatments in psychiatry still count as experimentalOther · 2026 · Evidence: Low
- Two ketamine doses worked similarly across depression, PTSD, anxiety and OCDRCT · 2026 · Evidence: Low
- Review finds psychedelic therapy research uses scattered, inconsistent ways of measuring resultsSystematic review · 2026 · Evidence: Low
- Review of 13 trials: MDMA and IV ketamine have the most PTSD evidence, results mixedSystematic review · 2026 · Evidence: Moderate
- A scoping review of how psychedelics affect thalamus-to-cortex brain circuitsSystematic review · 2026 · Evidence: Very low
- A review proposing two routes for turning ibogaine into a medicineSystematic review · 2026 · Evidence: Very low
- Review: can psychedelics and ketamine change how people read social cues?Systematic review · 2026 · Evidence: Low
- What predicts improvement when ketamine is paired with therapy for PTSDMeta-analysis · 2026 · Evidence: Low
- How music is chosen and used in psychedelic-assisted therapy trials: a systematic reviewSystematic review · 2026 · Evidence: Low
- Psilocybin and anxiety, quality of life and functioning in 15 veterans with hard-to-treat depressionOpen-label trial · 2026 · Evidence: Very low
- Review of 30 years of ibogaine research finds evidence too weak to support clinical useSystematic review · 2026 · Evidence: Low
- Review of where psychedelic-assisted therapies stand in the clinic and in regulationOther · 2026 · Evidence: Very low
- MDMA-assisted therapy for PTSD: pooled trial results show symptom drops but very low certaintyMeta-analysis · 2026 · Evidence: Low
- Placebo groups in psychedelic trials also improved, but less than treatment groupsMeta-analysis · 2026 · Evidence: Moderate
- Review of ketamine combined with psychotherapy: little proof the therapy part adds benefitSystematic review · 2026 · Evidence: Low
- What veterans described after a single ibogaine session for PTSD and brain injuryOpen-label trial · 2026 · Evidence: Low
- Stress hormone marker was lower in people with both depression and PTSD, before and after ketamineOther · 2026 · Evidence: Low
- Review of 23 meta-analyses on psychedelic-assisted therapy for mental disordersSystematic review · 2025 · Evidence: Moderate
- Ketamine drip for acute injury pain linked to lower PTSD and anxiety scores at 6 monthsRCT · 2025 · Evidence: Moderate
- What predicts who responds to psychedelic-assisted therapy? A review of 54 studiesSystematic review · 2025 · Evidence: Low
- Review of seven trials of IV ketamine for PTSD finds mixed but promising resultsSystematic review · 2025 · Evidence: Moderate
- Stronger "mystical" experiences during ibogaine linked to bigger PTSD drops in 30 veteransObservational · 2025 · Evidence: Low
- Pooled review of 30 trials of MDMA and psychedelics for mental disordersMeta-analysis · 2025 · Evidence: Moderate
- Ketamine infusions and markers of biological aging in 20 people with depression or PTSDOpen-label trial · 2025 · Evidence: Very low
- Review of ayahuasca research finds little controlled evidence for mental health usesOther · 2025 · Evidence: Very low
- Review: how psychedelics and ketamine may reshape brain connections in depression, PTSD and addictionOther · 2025 · Evidence: Very low
References
- Mitchell JM, et al. MDMA-assisted therapy for severe PTSD: a randomized, double-blind, placebo-controlled phase 3 study. Nature Medicine. 2021;27(6):1025–1033. Source
- Mitchell JM, et al. MDMA-assisted therapy for moderate to severe PTSD: a randomized, placebo-controlled phase 3 trial. Nature Medicine. 2023;29(10):2473–2480. Source
- Psychiatric Times. FDA releases Complete Response Letter on declining MDMA-assisted therapy for PTSD. 2025. Source
- Feder A, et al. A randomized controlled trial of repeated ketamine administration for chronic PTSD. American Journal of Psychiatry. 2021;178(2):193–202. Source
- Cherian KN, et al. Magnesium-ibogaine therapy in veterans with traumatic brain injuries. Nature Medicine. 2024;30(2):373–381. Source