● Species profile
Liberty Cap
Psilocybe semilanceata
Photo: Alan Rockefeller, CC BY-SA 3.0, via Wikimedia Commons
A small, pointed psilocybin mushroom from grassy pastures across Europe and beyond. Its tiny size and toxic lookalikes make it one of the riskier mushrooms to identify. Legal status varies by country.
Historical Use and Context
The liberty cap is Europe's best-known psilocybin mushroom, named for its resemblance to the Phrygian cap that became a symbol of the French Revolution.
In 1799 a London physician described a family who picked it in Green Park, cooked it into a broth, and had vivid hallucinations. It is one of the earliest clear medical records of psilocybin's effects.
The Short Answer
Wild psilocybin mushroom; research is on purified psilocybin, and look-alikes can kill.
Liberty caps contain psilocybin, which clinical trials are testing for depression in supervised clinical settings. Picking them wild is risky because deadly look-alikes grow in the same grass, and psilocybin is controlled under US federal law (Oregon and Colorado have regulated programs, and New Mexico's medical program is due by the end of 2026).
How Strong Is the Research?
Several RCTs of psilocybin
What the Trials Measured
Psilocybin trials tracked depression over 3 to 12 weeks after supervised sessions. Poisoning from a toxic look-alike can take 6 to 24 hours to show and can wreck the liver.
⚠ Who Should Not Use Psilocybin
- Anyone with a personal or family history of psychosis, schizophrenia or bipolar disorder. Psilocybin trials exclude them because of the risk of triggering episodes.
- People with heart disease, uncontrolled high blood pressure or a past heart attack. Psilocybin raises heart rate and blood pressure, and there is a case report of a heart attack after eating liberty caps.
- Anyone taking lithium or other psychiatric medicines. Trials exclude lithium users and manage other drugs with a doctor.
- Pregnant or breastfeeding people, and teens. Poison center calls about psilocybin in 13 to 25 year olds more than doubled after 2018.
- Anyone who cannot tell small brown mushrooms apart with certainty. Guessing can mean eating a deadly species instead.
Law, Safety and Look-Alikes
1
Legal Status
Psilocybin is a Schedule I controlled substance under US federal law. Oregon and Colorado run state-regulated programs. New Mexico passed a medical psilocybin law, and its program is due to start by the end of 2026. Many other countries ban it too.
2
Setting and Supervision
In research, psilocybin is given as a measured dose with trained staff present, screening beforehand and follow-up after, not picked and eaten in a field.
3
Deadly Look-Alikes
Liberty caps are small brown mushrooms with a pointed cap, and they share lawns with Galerina and Conocybe species that carry the same liver toxin as the death cap, plus sweat-inducing Inocybe species.
The Research in Plain English
2024 · 4,055 poison center cases, ages 13 to 25 · US data review
Psilocybin exposure calls were steady from 2013 to 2018, then rose sharply, more than tripling in teens by 2022. About 3 in 4 single-substance cases needed medical care. Read the study ↗
1998 · 1 person · case report
Doctors reported a heart attack (myocardial infarction) after eating liberty caps. It is a single case, but it is one reason trials screen out people with heart problems. Read the study ↗
2021 · 59 adults with depression · RCT vs escitalopram
This trial used purified psilocybin, not wild mushrooms, and compared it with a common antidepressant over 6 weeks. There was no clear difference on the main depression measure. Read the study ↗
This Liberty Cap guide summarizes published research for general education and isn't medical advice. Talk to your doctor before starting any supplement, especially if you take medication.
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