Plant medicine: what the research says

Trials are testing some plant medicines in medical settings; none is approved in the UK or EU. Microdosing did no better than a placebo.

What a session is

On Sissoo, plant medicine sessions are conversations with a practitioner: preparing for an experience, talking it through afterwards (often called integration) or guidance on microdosing. Some practitioners also run retreats abroad. Sissoo does not supply any substance.

What the research says

• Severe low mood: in early trials, one plant medicine given with psychological support in a clinic eased severe low mood for up to 5 weeks. In one study it did no better than a standard antidepressant. Limited evidence · NCCIH, 2024 · TGA (Australia), 2023
• Trauma: trials of a related medicine given with therapy looked promising, but in 2024 advisers to US regulators found the data did not show it works. Limited evidence · US FDA, 2024 · TGA (Australia), 2023
• Microdosing for mood and wellbeing: people taking tiny regular doses felt better, but so did people taking a placebo, with no clear difference. Good evidence it does not help · eLife, 2021
• Ceremonies and retreats: only small studies, mostly without a comparison group. No good evidence yet
• Stress, sleep, grief and other needs: not studied in the sources we use. No good evidence yet

More on each need: Lift your mood

Is it safe?

These substances can cause intense anxiety and confusion, raise blood pressure and heart rate, and in rare cases lead to lasting psychosis. They are not safe for people with psychosis, schizophrenia, severe bipolar disorder or borderline personality disorder, and they may interact with medicines, including antidepressants. Products bought outside a clinic may contain other, dangerous drugs. NCCIH, 2024

Sessions on Sissoo complement medical care and never replace it. Please don’t stop or change any treatment without talking to your doctor. If you feel very low or think about ending your life, call your local emergency number now.

Is it legal?

In most countries, including the UK and most of the EU, possessing or supplying these substances is a crime. A few places allow some uses: since 2023, approved psychiatrists in Australia may prescribe two of them, and some US states license supervised services. Always check the law where you are. TGA (Australia), 2023 · NCCIH, 2024

Plant medicine sessions on Sissoo: At the time of service provision, only clients for whom possession of the related substance is lawful where they are, or who hold a legal authorisation (such as Health Canada Special Access, a clinical trial or a licensed service), may participate. Substance procurement is solely the responsibility of you, the client. Practitioners on Sissoo do not supply, sell, source or recommend sources of any substance.

Checked 18 October 2026. Next check by April 2027. How we rate the evidence.