St John’s wort
Hypericum perforatumIn Turkish, kantaron names two different plants: yellow kantaron (Hypericum) and red kantaron (Centaurium). The red kantaron oil, however, is made from the yellow one.
What is St John’s wort?
St John’s wort (Hypericum perforatum) is a plant of the Hypericaceae family. Traditions that use it: Anatolia and the Mediterranean. Part used: flowering tops.
What is St John’s wort used for?
Traditional use: The flowers are steeped in olive oil in the sun to make red kantaron oil, used for burns, wounds and stomach ulcers. Scientific evidence: clinical. According to a Cochrane review, standardised extracts work better than placebo for mild to moderate depression and about as well as some antidepressants.
Is St John’s wort safe?
Safety label: caution. It weakens many medicines: birth control pills, blood thinners, some heart and transplant drugs. With antidepressants it can cause serotonin syndrome. It can cause sun sensitivity.
Traditional use
The flowers are steeped in olive oil in the sun to make red kantaron oil, used for burns, wounds and stomach ulcers.
Because it flowers at midsummer, it was considered a plant that drives away evil spirits and was gathered on St John’s Day (24 June).
In nature
Mix-up risk
Many Hypericum species grow in Türkiye. The translucent dots seen when a leaf is held to the light identify Hypericum perforatum.
Preparation
For the oil, flowers sit in olive oil in the sun for 4–6 weeks. Also used as tea or standardised extract.
What science says
According to a Cochrane review, standardised extracts work better than placebo for mild to moderate depression and about as well as some antidepressants. In Germany it is used as a medicine for depression.
How strong is the evidence?
Claims often repeated online about St John’s wort, and what science says today.
| Claim | Evidence | Note |
|---|---|---|
| Works for mild to moderate depression | Clinical evidence | A Cochrane review found standardised extracts better than placebo and close to some antidepressants. No role in severe depression. |
| St John’s wort oil heals wounds and burns | Traditional only | Recognised by the EMA externally for small wounds and mild burns as traditional; clinical evidence is limited. |
| Heals stomach ulcers | No evidence | No human studies show this; no substitute for ulcer treatment. |
| Reduces menopause symptoms | Limited evidence | Slight benefit through mood in small studies; inconclusive. |
Common mistakes
- Taking it with birth control pills, blood thinners or antidepressants. The interactions are very serious.
- Going into the sun after applying the oil: it can cause sun sensitivity.
- Swapping depression treatment for St John’s wort without telling your doctor, or stopping an antidepressant suddenly.
Frequently asked
What is St John’s wort oil used for?
Traditionally applied to small cuts, scrapes and mild burns. It is for the skin, not for drinking.
How long does it take to work?
In depression studies the effect usually appeared within 2–4 weeks. This is a treatment that needs a doctor’s follow-up.
Can I use it with other medicines?
It weakens many medicines. If you take regular medication, ask your pharmacist first.
Safety
It weakens many medicines: birth control pills, blood thinners, some heart and transplant drugs. With antidepressants it can cause serotonin syndrome. It can cause sun sensitivity.
Drug interactions
| Medicine or substance | Why it matters |
|---|---|
| Birth control pills | Speeds up liver enzymes (CYP3A4) and weakens the pill; unintended pregnancies have been reported. |
| Blood thinners (warfarin), digoxin | Lowers drug levels; risk of clots or heart rhythm problems. |
| Transplant drugs (ciclosporin, tacrolimus) | Lowers drug levels; organ rejection has been reported. |
| Antidepressants, triptans, tramadol | Risk of serotonin syndrome. |
| HIV and some cancer drugs | Can lower drug levels enough to make treatment fail. |
This list is not complete. If you take regular medication, ask your pharmacist or doctor before trying St John’s wort.
Similar plants
Sources
- EMA monographHyperici herba: European Medicines Agency herbal assessment
- NCCIHUS National Center for Complementary and Integrative Health: use and safety summary
- ResearchLinde ve ark. 2008, Cochrane: St John’s wort for major depression
- BookBaytop T. Türkiye’de Bitkiler ile Tedavi: Geçmişte ve Bugün. 2. baskı. İstanbul: Nobel Tıp Kitabevleri; 1999.
- Botanical recordKew Plants of the World Online: Hypericum perforatum
- Titles of research sources are summarised in Turkish on the Turkish page; links open the original English publications.
Written by Edanaz Tınmazlar · Last reviewed: · Türkçe