St. John’s Wort: Natural Mood Booster or Risky Remedy?

St. John’s wort (Hypericum perforatum) is a bright yellow, summer-blooming plant that has been used for centuries as a healing herb. Its name comes from St. John the Baptist, since the flowers typically bloom near his feast day in late June. Ancient traditions in Greece, Islamic medicine, and Chinese herbal practice all turned to this plant for support with wounds, low mood, and general vitality. Today, it’s one of the most widely studied herbs for mental and emotional wellness—especially mild to moderate depression. But with its benefits come important cautions.

What the Research Says

Dozens of clinical studies have explored St. John’s wort, with the strongest evidence pointing to its use for depression. Reviews of more than 20 studies suggest the herb may be as effective as standard antidepressant medications, such as SSRIs and tricyclic antidepressants, for mild to moderate cases. Some research also suggests it may help ease menopausal mood changes, seasonal mood shifts, and certain anxiety-related disorders.

Beyond mood, St. John’s wort has been explored for conditions such as:

• Premenstrual syndrome (PMS) – easing physical and emotional discomfort before menstruation
• Obsessive-compulsive disorder (OCD) – reducing intrusive thoughts and compulsive behaviors
• ADHD – improving focus and reducing restlessness in some cases
• Somatic symptom disorder – reducing health-related anxiety
• Skin issues – when applied topically, may support wound healing, bruises, burns, or sore muscles

Although these studies are promising, most findings are preliminary. Larger, long-term trials are needed before firm conclusions can be made.

How People Use It

St. John’s wort is typically taken as a capsule or tablet, often standardized to contain 0.3% hypericin, one of its active compounds. Adults may take around 300 mg up to three times per day, though dosing should always be guided by a healthcare provider.

Other common forms include:

• Tea – made by steeping the dried flowers and leaves
• Tincture – liquid extracts taken in water or juice
• Creams and oils – applied to the skin to support wound healing and ease inflammation

One important note: topical applications can increase skin sensitivity to sunlight, so they are often recommended for nighttime use.

Safety and Side Effects

For generally healthy adults who are not on prescription medications, St. John’s wort is considered safe for up to 12 weeks, with some research suggesting longer use may also be tolerated. Still, it can cause side effects such as dry mouth, dizziness, stomach upset, restlessness, or heightened sensitivity to sunlight.

More serious concerns include its potential to worsen conditions like bipolar disorder or schizophrenia, or to cause agitation and insomnia in some people. Pregnant or breastfeeding women are advised to avoid it, as it may pose risks to infants.

The Big Concern: Drug Interactions

The greatest caution with St. John’s wort is its ability to interfere with prescription medications—sometimes in life-threatening ways. It can reduce the effectiveness of drugs such as:

• Antidepressants (raising risk of serotonin syndrome)
• Birth control pills
• Anti-rejection drugs for organ transplants
• HIV medications
• Chemotherapy drugs
• Blood thinners (e.g., warfarin)
• Certain heart and cholesterol medicines

Because of these risks, anyone considering St. John’s wort should consult a healthcare provider before use.

Where to Find It

St. John’s wort is widely available in health food stores, pharmacies, and online in capsules, teas, tinctures, and oils. Since dietary supplements are not regulated as strictly as drugs, it’s best to choose products that are third-party tested for purity and potency.

Bottom Line

St. John’s wort holds a unique place in herbal medicine. It bridges ancient tradition with modern research, showing potential as a natural ally for mood and emotional balance. But its risks—particularly with drug interactions—mean it should never be used casually. If you’re curious about adding this herb to your wellness routine, let your healthcare provider know so you can make an informed, safe decision together.