St. John's Wort

A well-researched herb for mild to moderate depression, but with significant drug interactions.

Also known as: Hypericum perforatum • Klamath weed

other Names
Hypericum perforatum, Goatweed, Amber
primary Benefits
Alleviates symptoms of depression, reduces anxiety
common Dose
300mg, 3 times per day
best Form
Standardized extract (0.3% hypericin, 2-5% hyperforin)
timing
With meals to reduce digestive upset
safety Rating
Effective, but has many drug interactions

Overview

St. John's Wort is a flowering plant that has been used for centuries to treat nerve pain and mood disorders. Its active constituents, primarily hypericin and hyperforin, are believed to work by increasing the levels of several neurotransmitters in the brain, including serotonin, dopamine, and norepinephrine. It is one of the most studied herbal remedies for depression.

Key Benefits

Treats Mild to Moderate Depression

Numerous studies have found St. John's Wort to be as effective as standard antidepressant medications for mild to moderate depression, with fewer side effects.

Eases Anxiety

It can also have a calming effect, helping to reduce symptoms of anxiety and nervousness.

May Help with PMS and Menopause Symptoms

Some research suggests it can alleviate the psychological and physical symptoms of PMS and menopause.

Dosage & How to Take

The standard dosage is 300mg of a standardized extract taken three times daily.

PurposeDoseNotes
Depression900mg/daySplit into three 300mg doses.
Anxiety/PMS300-900mg/dayStart with a lower dose and adjust as needed.

Best Time to Take

Best taken in divided doses with meals throughout the day.

With or Without Food

Yes, taking it with food can help prevent gastrointestinal side effects like nausea.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Standardized Extract (Capsules/Tablets)HighDepressionEnsure the product is standardized to 0.3% hypericin and/or 2-5% hyperforin.
Tea/TinctureVariableMild stressDosage is less consistent and may be less effective.

Side Effects & Safety

Common

  • Stomach upset
  • Dry mouth
  • Dizziness
  • Fatigue
  • Photosensitivity (increased sun sensitivity)

Rare

  • Anxiety
  • Sexual dysfunction
  • Psychosis (in rare cases)

Contraindications

  • Pregnancy and breastfeeding
  • Bipolar disorder
  • Schizophrenia
  • Upcoming surgery

Interactions

Antidepressants (SSRIs, etc.)High

High risk of serotonin syndrome.

Birth control pillsHigh

Can reduce the effectiveness of oral contraceptives.

Blood thinners (e.g., Warfarin)High

Reduces effectiveness, increasing risk of clots.

Many other medicationsHigh

Induces liver enzymes (CYP3A4), accelerating the metabolism of numerous drugs.

Scientific Research

2008Cochrane Database of Systematic Reviews

St John's wort for major depression.

St John's wort extracts are more effective than placebo and similarly effective as standard anti-depressants for major depression.

Food Sources

Not consumed as a food.

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.