Everything You Need to Know About

Saint John’s Wort (Hypericum perforatum)

Botanical family: Hypericaceae
Parts used: Leaves, Flowers
Saint John’s Wort (Hypericum perforatum)
Left Image

St. John’s wort (Hypericum perforatum) is a powerful herb celebrated for its wide-ranging health benefits, particularly its role in mental health. It has been extensively used to alleviate symptoms of mild to moderate depression and anxiety, with research supporting its effectiveness in influencing neurotransmitter levels. Beyond its mental health applications, St. John’s wort is valued for relieving nerve pain, promoting wound healing, and combating viral infections. These therapeutic effects are linked to its rich composition of bioactive compounds, including hypericin and hyperforin, which provide anti-inflammatory, antiviral, and analgesic properties. Known for its bright yellow flowers, which release a red pigment when crushed, St. John’s wort has been a part of European herbal medicine for centuries. Whether taken as a tincture, tea, or applied externally as an infused oil, it continues to be a trusted ally in supporting physical and emotional wellbeing.

Key Benefits:

  • Antidepressant and Anxiolytic Effects
  • Nerve Pain Relief
  • Antiviral and Antimicrobial Actions
  • Wound Healing and Skin Care
  • Support for Seasonal Affective Disorder (SAD)

St. John’s wort is well documented for its ability to treat mild to moderate depression. Studies have shown that the herb’s active constituents, including hyperforin and hypericin, work by modulating neurotransmitter levels, such as serotonin, dopamine and norepinephrine, thereby improving mood and reducing anxiety (Linde et al., 2008; Hobbs, 1998; McIntyre, 2019). It is often used as a natural alternative to conventional antidepressants, with comparable efficacy but fewer side effects (Davidson & Connor, 2000; Shrivastava & Dwivedi, 2015). It is also indicated for nervous exhaustion, tension, and anxiety, but should be taken for 2 to 3 months before producing lasting effects (McIntyre, 2019).

The herb’s analgesic properties are particularly beneficial for conditions involving nerve pain, such as sciatica, trigeminal neuralgia, arthritic pain and shingles (Sarıyıldız et al., 2023; Uslusoy et al., 2019; Olajide, 2009). St. John’s wort’s ability to repair nerve damage and soothe inflamed tissues has earned it the nickname "arnica for the nerves" (Chevallier, 1996). It is commonly applied in the form of an infused oil or salve to provide relief from these painful conditions (Bennett, 2014; McIntyre, 2019).

St. John’s wort possesses notable antiviral properties, particularly against viruses like herpes simplex, influenza and hepatitis (McIntyre, 2019). Its bioactive compounds, hypericin and pseudohypericin, inhibit viral replication and can be used in the treatment of viral infections, including shingles and cold sores (Mohamed et al., 2022). Additionally, the herb’s antimicrobial effects make it useful in preventing infections in wounds and skin conditions (Chevallier, 1996; McIntyre).

Traditionally used to promote wound healing (when applied topically), St. John’s wort’s vulnerary properties (promoting wound healing and tissue repair) help reduce inflammation and accelerate tissue regeneration. This makes it effective for treating cuts, burns, and bruises. Infused oils or salves are applied topically to soothe the skin and support the healing process (Samadi et al., 2010).

The uplifting nature of St. John’s wort, as well as its ability to increase sensitivity to sunlight, has made it a popular remedy for Seasonal Affective Disorder (SAD), a type of depression related to changes in seasons (McIntyre, 2019). Research suggests that the herb, when combined with light therapy, can significantly alleviate symptoms of SAD, helping individuals feel more energised and mentally balanced during the darker months (Kasper, 1997).

Safety

St John's wort must be used with caution due to its potential to interact with various medications. One of the primary concerns is its ability to induce cytochrome P450 enzymes, particularly CYP3A4, which can significantly reduce the efficacy of certain drugs by increasing their metabolism. This includes medications such as oral contraceptives, anticoagulants, immunosuppressants, and some antidepressants, among others (Borrelli & Izzo, 2009). Additionally, combining St John’s wort with selective serotonin reuptake inhibitors (SSRIs) can lead to serotonin syndrome, a potentially life-threatening condition (Hoffmann, 2003). Moreover, the herb has been associated with photosensitivity, particularly in fair-skinned individuals, necessitating caution when exposed to UV light (Barnes et al., 2001). Due to these interactions, it is advised that individuals on prescribed medications, particularly those with conditions such as epilepsy, depression, or those requiring consistent drug efficacy, should consult with a healthcare professional before using St John’s wort (Davidson & Connor, 2000). As with any herbal remedy, it is crucial to seek medical advice, especially if you have a pre-existing condition, if you are pregnant, or if you are taking prescription medications.

Key Body Systems Saint John’s Wort (Hypericum perforatum) relates to

Saint John’s Wort (Hypericum perforatum)
Skin
Saint John’s Wort (Hypericum perforatum)
Digestive System
Saint John’s Wort (Hypericum perforatum)
Nervous system
Saint John’s Wort (Hypericum perforatum)
Immune System

Energetics

Saint John’s Wort (Hypericum perforatum)
Warming
Saint John’s Wort (Hypericum perforatum)
Drying

Key actions

Antidepressant; Anxiolytic; Anti-inflammatory; Vulnerary; Antiviral

Saint John’s Wort (Hypericum perforatum)

Key uses

Mild depression, anxiety; Nerve pain; Wound healing

Where to Find Saint John’s Wort (Hypericum perforatum)

Saint John’s Wort (Hypericum perforatum)

What it looks like & where to find it

St John's wort is a distinctive and easily recognisable herbaceous plant belonging to the Hypericaceae family, which includes around 400 species worldwide. This family is characterised by its bright yellow flowers, often with numerous stamens, a feature that St John’s wort exhibits in abundance. The plant typically grows up to 60 cm in height, with upright stems that are often reddish and bear pairs of narrow, oblong leaves. A key identifying feature of the leaves is the presence of small, translucent dots, which are actually tiny oil glands (containing hypericin and other active compounds) that give the appearance of being perforated when held up to the light—hence the species name perforatum. The bright yellow, star-shaped flowers have five petals and are usually adorned with black dots along their edges, another useful trait for identification. These flowers bloom from mid-summer to early autumn and are often (around St John’s day—hence the common name!) found in clusters at the top of the plant.

References

References:

Barnes, J., Anderson, L. A., & Phillipson, J. D. (2001). St John's wort (Hypericum perforatum L.): A review of its chemistry, pharmacology and clinical properties. Journal of Pharmacy and Pharmacology, 53(5), 583-600. https://doi.org/10.1211/0022357011775910 

Bennett, R. R. (2014). The Gift of Healing Herbs. North Atlantic Books.

Borrelli, F., & Izzo, A. A. (2009). Herb-drug interactions with St John's wort (Hypericum perforatum): An update on clinical observations. AAPS Journal, 11(4), 710-727. https://doi.org/10.1208/s12248-009-9146-8 

Chevallier, A. (1996). The Encyclopaedia of medicinal plants. DK Publishing.

Davidson, J. R. T., & Connor, K. M. (2000). Herbs for the mind: What science tells us about nature’s remedies for depression, stress, memory loss, and insomnia. The Guilford Press.

Hobbs, C. (1998). St. John’s wort: Ancient herbal protector. Herbal Therapeutics. https://www.researchgate.net/publication/11728098_St_John's_wort--ancient_herbal_protector 

Hoffmann, D. (2003). Medical Herbalism: The Science and Practice of Herbal Medicine. Healing Arts Press.

Johnson, R. L., Foster, S., Low Dog, T., & Kiefer, D. (2012). National Geographic guide to medicinal herbs: The world’s most effective healing plants. National Geographic.

Kasper, S. (1997). Treatment of seasonal affective disorder (SAD) with Hypericum extract. Pharmacopsychiatry, 30(Suppl. 2), 89-93. https://doi.org/10.1055/s-2007-979526

Klemow, K. M., Bartlow, A., Crawford, J., Kocher, N., Shah, J., & Ritsick, M. (2011). Medical attributes of St. John’s wort (Hypericum perforatum). In I. F. F. Benzie & S. Wachtel-Galor (Eds.), Herbal medicine: Biomolecular and clinical aspects (2nd ed., Chapter 11). CRC Press/Taylor & Francis. https://www.ncbi.nlm.nih.gov/books/NBK92750/

Linde, K., Berner, M., & Kriston, L. (2008). St John’s wort for major depression. The Cochrane Database of Systematic Reviews, 2008(4), CD000448. https://doi.org/10.1002/14651858.CD000448.pub3

McIntyre, A. (2019). The complete herbal tutor. Aeon. 

Mohamed, F. F., Anhlan, D., Schöfbänker, M., Schreiber, A., Classen, N., Hensel, A., & Ludwig, S. (2022). Hypericum perforatum and its ingredients hypericin and pseudohypericin demonstrate an antiviral activity against SARS-CoV-2. Pharmaceuticals, 15(5), 530. https://doi.org/10.3390/ph15050530

Olajide, O. A. (2009). Inhibitory effects of St. John's Wort on inflammation: Ignored potential of a popular herb. Journal of Dietary Supplements, 6(1), 28-32. https://doi.org/10.1080/19390210802687247

Samadi, S., Khadivzadeh, T., Emami, A., Moosavi, N. S., Tafaghodi, M., & Behnam, H. R. (2010). The effect of Hypericum perforatum on the wound healing and scar of caesarean. Journal of Alternative Complementary Medicine, 16(1), 113-117. https://doi.org/10.1089/acm.2009.0317

Sarıyıldız, A., Kaplan, H. M., Singirik, E., & Kozanoğlu, E. (2023). Modulatory effects of Hypericum perforatum extract on sciatic nerve injury-induced peripheral neuropathy: An experimental study on mice. Cukurova Medical Journal, 48(2), 513–521. https://doi.org/10.17826/cumj.1259761 

Shrivastava, M., & Dwivedi, L. (2015). Therapeutic potential of Hypericum perforatum: A review. International Journal of Pharmaceutical Sciences and Research, 6(12), 1000-1007. https://www.researchgate.net/publication/282325514_THERAPEUTIC_POTENTIAL_OF_HYPERICUM_PERFORATUM_A_REVIEW 

Uslusoy, F., Nazıroğlu, M., Övey, İ. S., & Sönmez, T. T. (2019). Hypericum perforatum L. supplementation protects sciatic nerve injury-induced apoptotic, inflammatory, and oxidative damage to muscle, blood, and brain in rats. Journal of Pharmacy and Pharmacology, 71(1), 83-92. https://doi.org/10.1111/jphp.12741