Herbal antidepressant (Hypericum perforatum)
St John's wort
Adult dose
Dose: Per product (typically 300mg standardised extract TDS)
Route: PO
Frequency: TDS
Clinical pearls
- Mild-moderate depression; not licensed in UK as medicine
- MHRA: many serious interactions — check before recommending
Contraindications
- Pregnancy/breastfeeding
- Concurrent antiretrovirals
- Concurrent ciclosporin/tacrolimus
- Concurrent SSRIs (serotonin syndrome)
- Severe depression
Side effects
- Photosensitivity
- GI upset
- Headache
- Serotonin syndrome (with serotonergic drugs)
- Mania switch
Interactions
- Many — strong CYP3A4 inducer + P-gp inducer
- Hormonal contraceptives (failure)
- Warfarin
- Digoxin
- Theophylline
- Antiretrovirals
- Ciclosporin
Monitoring
- Mood
- Drug levels (interacting drugs)
Reference: BNF; MHRA; NICE NG222; https://bnf.nice.org.uk/drugs/st-johns-wort/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Acute Behavioural Disturbance / Rapid Tranquillisation · RCEM 2022; RCPsych 2022; NICE NG10
- Self-Harm Presentation · NICE NG225 (2022)
- Capacity Assessment (Mental Capacity Act) · MCA 2005; Code of Practice
- Acute Psychosis Management · NICE CG178 2014
- Depression Management · NICE CG90 2022
- Lithium Therapy Monitoring · NICE CG185 / BNF