Potential Side Effects and Warnings of St. John’s Wort

St. John’s Wort (Hypericum perforatum) is widely recognized as a traditional herbal remedy often used to help manage symptoms of mild to moderate depression and anxiety. Despite its popularity and historical use, this supplement carries a range of side effects and interaction risks that users need to be aware of. This article dives into the most reported side effects, precautions for specific groups, drug interactions, and important warnings associated with St. John’s Wort.

What Is St. John’s Wort?

St. John’s Wort is a flowering plant native to parts of Europe and Asia, noted for its yellow petals and traditional medicinal uses dating back to ancient Greece. It is commonly utilized today as an over-the-counter supplement for mood disorders, but unlike prescription antidepressants, it is not regulated by the FDA for safety or effectiveness.

Common Side Effects of St. John’s Wort

While most people tolerate St. John’s Wort well, certain mild to moderate side effects are quite common, especially during the initial weeks of use:

• Dizziness and drowsiness
• Digestive disturbances like diarrhea or constipation
• Upset stomach or gastrointestinal discomfort
• Dry mouth
• Headache
• Insomnia or disturbed sleep
• Fatigue or tiredness
• Anxiety and restlessness

These effects are typically mild and transient, often easing as the body adjusts to the supplement within a few weeks.

Less Common and Rare Side Effects

Some users experience less typical reactions, which can still impact quality of life or require medical attention:

• Sexual dysfunction, such as decreased libido
• Sun sensitivity (photosensitivity), leading to skin rashes or burns on exposure to sunlight
• Skin tingling or sensations (paresthesia)
• Confusion or increased anxiety

Among these, photosensitivity is one of the most reported, particularly at higher doses, making it important for users to limit sun exposure or use sun protection during supplementation.

Serious Adverse Effects

Although severe side effects are rare, certain serious reactions can occur, especially with inappropriate use or drug combinations:

• Allergic reactions—swelling, hives, or breathing difficulties
• Serotonin syndrome: Characterized by confusion, muscle rigidity, fever, sweating, and elevated heart rate. This is especially likely if taken with other substances that increase serotonin (e.g., SSRIs).
• Eye damage: Rare phototoxicity cases leading to eye issues
• Worsening of mood disorders (e.g., triggering mania in bipolar patients or psychosis in schizophrenia)

If any of these symptoms appear, the use of St. John’s Wort should be stopped immediately, and a healthcare professional should be consulted.

Mechanisms and Causes of Side Effects

Many side effects of St. John’s Wort are linked to its impact on neurotransmitters like serotonin, dopamine, and norepinephrine—brain chemicals involved in mood regulation. Additionally, its ability to induce liver enzymes (especially cytochrome P450 3A4) accelerates the metabolism of many drugs, reducing their efficacy or increasing toxicity risks.

St. John’s Wort and Drug Interactions

One of the most significant safety concerns with St. John’s Wort is its potential for interacting with a wide array of prescription and over-the-counter drugs. It can both reduce the effectiveness of medications and increase the risk of serious side effects.

Due to these risks, users are always advised to consult a healthcare professional before starting St. John’s Wort, especially if taking any other medications.

Special Populations: Precautions and Warnings

Pregnant and Breastfeeding Women

• St. John’s Wort may be unsafe during pregnancy. There’s some evidence it could lead to birth defects if used during pregnancy.
• When used while breastfeeding, it may cause colic, sedation, and irritability in infants.

Until more extensive safety data is available, it is not recommended for pregnant or nursing mothers.

Children and Adolescents

• Short-term use (up to 8 weeks) may be safe for children aged 6–17, but only under strict medical supervision.
• The lack of robust long-term safety data means it should generally be avoided unless recommended by a healthcare professional.

People with Psychiatric or Neurological Disorders

• Individuals with bipolar disorder are at particular risk, as St. John’s Wort can trigger mania or accelerate cycling between depression and mania.
• Those with major depressive disorder may experience manic episodes.
• It may induce psychosis in patients with schizophrenia.
• Should not be used in people with Alzheimer’s, as it can worsen confusion and dementia symptoms.

Pre-Surgical Precautions

• St. John’s Wort may adversely interact with anesthesia, increasing the risk of serious heart or serotonin-related complications during surgery.
• Discontinue use at least two weeks prior to any scheduled surgery.

Photosensitivity and Skin Reactions

St. John’s Wort is associated with a heightened risk for photosensitivity—an increased sensitivity of the skin to sunlight and artificial UV sources. Manifestations include:

• Severe sunburns
• Skin rashes
• Eye discomfort in bright light (photophobia)

Photosensitivity reactions are dose-dependent and increase with higher supplementation or topical application, particularly in fair-skinned individuals. Wearing sunscreen and protective clothing is advised for users.

Dosage and Safety Period

St. John’s Wort is generally considered safe for adults at doses up to 900 mg daily for up to 12 weeks in clinical studies. However, exceeding recommended doses raises the likelihood of all forms of side effects and medical complications. Use well-established, standardized extracts and avoid self-medicating with unregulated preparations.

Who Should Avoid St. John’s Wort?

Certain populations should not take St. John’s Wort, including:

• Pregnant and breastfeeding women
• Individuals taking prescription antidepressants or mood stabilizers
• People scheduled for surgery within two weeks
• Patients with bipolar disorder, schizophrenia, or Alzheimer’s disease
• Those on medications with a high risk of interaction (see previous table)

Tips for Safe Use

• Always consult your healthcare provider before using St. John’s Wort, especially if you have existing medical conditions or are on any medications.
• Use standardized, reputable products to ensure dosing accuracy and minimize risk.
• Monitor for any signs of adverse effects or drug interactions and report these promptly.
• Be vigilant about sun protection during use.

Alternatives to St. John’s Wort

If you experience problematic side effects or cannot take St. John’s Wort because of medication interactions or existing conditions, consider these alternatives (after consulting with your physician):

• Other dietary supplements (after medical review), such as omega-3 fatty acids or S-Adenosyl methionine (SAMe)
• Cognitive Behavioral Therapy (CBT) or other professional psychotherapy
• Conventional antidepressant medications with regular medical supervision
• Lifestyle interventions such as exercise, a balanced diet, and adequate sleep

Frequently Asked Questions (FAQs)

Q: Can I take St. John’s Wort if I’m already on antidepressants?

A: St. John’s Wort should not be combined with prescription antidepressants like SSRIs or SNRIs due to the risk of serotonin syndrome, a potentially life-threatening condition. Always consult your physician before combining treatments.

Q: How soon do side effects appear after starting St. John’s Wort?

A: Most common side effects—like digestive upsets, dizziness, or sleep disturbances—occur within the first few weeks and usually subside as your body adjusts to the supplement.

Q: Is St. John’s Wort safe for long-term use?

A: Long-term safety data is lacking. Clinical studies generally suggest using it only for periods up to 8–12 weeks. Ongoing use should be monitored by a healthcare provider.

Q: Are topical preparations of St. John’s Wort safer?

A: Topical (skin) formulations may still cause photosensitivity and severe skin reactions after sun exposure, so similar precautions are necessary.

Q: Can children use St. John’s Wort?

A: Limited evidence suggests short-term use may be safe for adolescents under strict medical supervision; long-term effects are not well known, so generally avoid unless recommended by a healthcare professional.

Takeaway

St. John’s Wort offers potential mood benefits for certain individuals, but its side effect profile and extensive drug interaction potential require careful consideration. Self-medicating without professional guidance—especially if you’re on prescription drugs or have underlying health issues—can lead to serious risks. Always consult a healthcare provider before beginning any new supplement regimen.

Author

Medha DebCommerce Editor

 

Medha Deb is a commerce editor with a master's degree in applied linguistics from the University of Hyderabad, which has allowed her to develop a deep understanding of language and its application in various contexts. She specializes in the areas of beauty, health, and wellness and is committed to ensuring that the content on the website is of the highest quality.

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