Reviewed records available

St. John's wort

Hypericum perforatum

Short trials found that some St. John's wort extracts had results similar to the SSRIs used as comparators for mild-to-moderate depression. The interaction problem is just as important as that signal: this plant can change how many medicines work.

Evidence snapshot reviewed October 16, 2026

Check the botanical identity in the Plant Atlas →

Botanical identity

Which plant this profile means

This profile is tied to Hypericum perforatum. Extract composition and hyperforin content can differ enough to affect both evidence transfer and interaction risk.

Scientific name
Hypericum perforatum
WCVP taxon ID
516286
Atlas record
Open this name in the Plant Atlas

Preparation boundaries

Same plant, different exposure

These forms stay separate in the evidence bank. A result for one cannot be copied onto the others.

mixed standardized extracts

aerial parts · Taken by mouth

Clinical findings for named or standardized extracts do not automatically transfer to every retail product. Hyperforin content and drug-interaction potential can differ.

Research-bot status

Some evidence cards are public. The rest of the queue isn’t.

The reviewed cards below cleared a separate publication check. The remaining candidate extractions stay private until their source, wording, and preparation match are reviewed.

Sources in review
1
Possible claims found
1
Still awaiting review
0
Blocked source
0

Research connections

What this ingredient has been studied around

Depression

A reviewed, preparation-specific evidence card is published for this source.

Reviewed evidence

1 source-linked record

Evidence synthesis Mixed or uncertain 27 trials with 3,808 participants

St. John's wort for depression: a short-term signal with a major interaction problem

In short trials involving people with mild-to-moderate depression, St. John's wort extracts had response and remission results similar to the SSRIs used as comparators. That does not make the herb a casual self-care option. The trials lasted four to twelve weeks, severe depression and high suicide risk were not established, and St. John's wort can interact with many medicines in clinically important ways.

What was studied
Oral Hypericum perforatum extracts used in short-term depression trials; extract composition and hyperforin content can differ
Setting
Studied alone
Why it ranks here
The short-term efficacy signal is meaningful, but long-term evidence is limited, high-risk depression was not established, products vary, and the interaction burden is unusually important.
Limits and cautions
  • All trials in the review lasted only four to twelve weeks.
  • The review did not establish benefit for severe depression, high suicidality, or suicide risk.
  • Different extracts and hyperforin contents are not assumed equivalent.
  • St. John's wort can alter the effects of many prescription medicines and can also interact with other serotonin-active products.
  • A comparison with selected SSRIs in trials does not establish that the herb is appropriate for a particular person or medication list.

Do not start, stop, or combine St. John's wort with an antidepressant, birth-control medicine, transplant medicine, anticoagulant, seizure medicine, HIV medicine, cancer treatment, or another prescription drug without checking with a qualified clinician or pharmacist.

Profile sources

Read the source material