St. John’s wort (Hypericum perforatum) has been a well-loved medicinal herb since time immemorial and has been used internally and externally for a variety of needs, especially as a mood regulator and as a first-aid remedy. Native to Europe and Asia and now widespread across the American east, St. John’s wort is best known today as an antidepressant, primarily for mild to moderate depression (it has not been found effective for major depressive disorder).

Because Hypericum is such a key herb in brain and mental health, it features strongly in my online courses Herbs for the Brain Beginner and Herbs for the Brain Certificate. We go in-depth in the courses to study St. John's wort as well as other nootropic and neurotrophic herbs such as ashwagandha, passionflower, turmeric, and ginkgo. Here, we share why St. John's wort is such a strong herb for maintaining a calm demeanor, easing stress, and supporting nerves.

Many of us know St. John’s wort as the “nerve herb” and in this article, we’ll dive into its origins, cultivation, active compounds, traditional uses, and the recent scientific studies that back up its reputation as a natural mood booster for brain and mental health. 

How to Grow and Harvest St. John’s Wort

St. John’s wort thrives in sunny, open areas, often along roadsides, in meadows, and on forest edges. As a hardy perennial (returning year after year), it can withstand drought, poor soils and dry climates. In some areas it is so prolific it is considered invasive.

The medicinal parts of St. John’s wort are primarily its yellow flowers and unopened buds, although many herbalists also use the leaves. Because it blooms brightly around midsummer, around the time of St. John’s Day (June 24), it is revered as a summer solstice herb. At this time, the flowers contain the highest concentration of active compounds and it makes the strongest remedy. When harvested, be sure to collect the upper flowering parts, avoiding the stems and lower leaves, which contain lower levels of active ingredients.

Though the flowers are yellow, you’ll notice your fingers turn a lovely red or crimson, which indicates a high presence of its active compound hypericin. This will also extend to your extraction oil, which (especially if placed in a sunny window) will turn bright red. (See my book Once Upon A Place: Forests, Caverns, and Other Places of Transformation in Myths, Fairy Tales and Film for a deep dive into colors in quest and adventure stories, especially red.)

Active Compounds and Medicinal Properties of St. John’s Wort

St. John’s wort contains a range of bioactive compounds that are the foundation of its therapeutic effects (both topically and internally). The two primary compounds believed to impact mood regulation are hypericin and hyperforin, though other flavonoids and essential oils play supportive roles.

1. Hypericin: This red pigment is one of the most studied compounds in St. John’s wort. Hypericin is believed to have an effect on serotonin, dopamine, and norepinephrine levels in the brain, all of which are neurotransmitters associated with mood regulation.
2. Hyperforin: This is believed to inhibit the reuptake of neurotransmitters like serotonin, dopamine, and norepinephrine. This action helps increase the availability of these mood-regulating neurotransmitters, similar to the mechanism of some antidepressant medications. (See more about SSRIs below.)
3. Essential Oils and Flavonoids: St. John’s wort also contains essential oils, such as terpenes and flavonoids, which have antioxidant and anti-inflammatory properties. Holistic herbalism advocates for using the whole plant rather than isolated chemicals, understanding that all the compounds naturally found in the plant probably work synergistically, enhancing the remedy’s overall strength.

St. John’s Wort for Mental Health

St. John’s wort has been used for centuries as a natural remedy for mood disorders, nervous exhaustion, and, historically even for protecting individuals against evil spirits. In medieval Europe, it was believed that the plant’s bright yellow solstice-blooming flowers symbolized the sun and could ward off darkness, both literally and figuratively. Herbalists used the flowers to make tinctures, oils, and teas to ease symptoms of melancholy and promote a positive outlook, and for first aid situations.

In traditional European herbalism, St. John’s wort was also used as a “nerve tonic” to ease nervous tension. Its reputation as a calming and mood-stabilizing agent has been passed down for generations, and modern scientific research supports many of these traditional uses.

How St. John’s Wort Works in the Brain

St. John’s wort is thought to work primarily by affecting neurotransmitter levels in the brain, particularly those associated with mood, such as serotonin, dopamine, and norepinephrine. To learn more about neurotransmitters and how they affect neuro diseases such as Alzheimer’s, Parkinson’s, depression, and disorders such as OCD and ADHD, check out our online courses Herbs for the Brain Beginner and Herbs for the Brain Certificate, which is approved or available for CEUs for nurses and acupuncturists.

Let’s take a closer look at how Hypericum affects neurotransmitters:

Serotonin

Known as the “feel-good” neurotransmitter, serotonin plays a key role in mood regulation, sleep, and emotional well-being. It’s commonly called the happy neurotransmitter because it supports feelings of satisfaction, happiness, and joy. But in the brain, neurotransmitters are sometimes blocked from doing their job in a process called “reuptake.” Hyperforin, one of St. John’s wort’s chemicals, is believed to inhibit the reuptake of serotonin, which allows more of this neurotransmitter to remain available in the brain. This effect is similar to that of pharmaceutical selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant medication.

Dopamine and Norepinephrine

These neurotransmitters are associated with motivation, energy, and focus, and dopamine in particular is associated with ambition and even muscle movement (lack of dopamine can lead to Parkinson’s Disease). Hyperforin also inhibits the reuptake of dopamine and norepinephrine, which can lead to an increase in these neurotransmitters’ levels in the brain. When there’s more of these neurotransmitters available, a person experiences better mood, improved focus, and (with dopamine) better muscle control. Though St. John’s wort has not been shown to ease symptoms of Parkinson’s, it is a strong nervous system support herb.

GABA and Glutamate

Some studies have also shown that St. John’s wort may impact GABA and glutamate levels in the brain. GABA is an inhibitory neurotransmitter associated with relaxation and calm, while glutamate is excitatory and linked to focus and alertness. By balancing these neurotransmitters, St. John’s wort may help relieve anxiety and promote a more balanced mental state.

Scientific and Clinical Evidence for St. John’s Wort in Mild to Moderate Depression

Extensive research has been conducted on St. John’s wort’s effectiveness as a remedy for mild to moderate depression. [Note: herbalists must be careful not to use the words treat, cure, diagnose or prevent. For more information about FDA compliance, see our online course Herbal Business Compliance.]

Many studies have demonstrated that St. John’s wort is effective in reducing symptoms of depression, with results comparable to prescription antidepressants but with fewer side effects such as nausea, weight gain or sleep disturbances. A large meta-analysis of 29 studies published in the Journal of the American Medical Association found that St. John’s wort was as effective as standard antidepressants for mild to moderate depression, and had fewer adverse effects. Another comprehensive review published in Cochrane Database of Systematic Reviews concluded that St. John’s wort was more effective than a placebo and had similar effectiveness to SSRIs for treating mild to moderate depression.

Unlike many prescription antidepressants, which can cause side effects like weight gain, nausea, sexual dysfunction, and fatigue, St. John’s wort is generally well-tolerated. However, it’s worth noting that St. John’s wort can interact with certain medications, such as birth control pills, blood thinners, and other antidepressants. And some people have had unpleasant side effects being exposed to sunlight while taking St. John's wort. Consulting a healthcare provider before beginning St. John’s wort is important, especially for individuals already on medication such as a pharmaceutical SSRI -- it is crucial to work with a health care team that includes both a physician and an herbalist to guard against serotonin syndrome.

Research has also highlighted St. John’s wort’s benefits for managing stress. By balancing neurotransmitter levels, it not only alleviates symptoms of mild to moderate depression but can also promote calm and improve resilience to stress. Studies suggest that St. John’s wort may be especially useful for individuals with seasonal affective disorder (SAD), a type of depression related to seasonal changes and reduced sunlight.

St. John’s Wort for Topical Nerve Repair

St. John’s wort is well-regarded not only for its mood-regulating properties but is traditionally admired for its ability to support nerve health and alleviate nerve pain, neuralgia, and tingling sensations topically. The herb is anti-inflammatory, analgesic, and nerve-calming (see our online course Herbal Actions) and I find it is a first-rate topical first-aid remedy, alongside elder leaf, mint, comfrey leaf, plantain, calendula, and yarrow.

For topical remedies, you want to use the oil. During an injury, nerves are weakened and possibly torn, and a topical oil (or cream or salve) of St. John’s wort with other vulnerary herbs can support quick healing. You can also employ a tincture internally; St. John’s wort strengthens nerves and “nerves” (both uses) and eases stress-related nerve tension, nervous exhaustion, or general neural health concerns. Think of it as serving as an anti-inflammatory from the inside out.

St. John’s Wort for Neuralgia and Nerve Pain

Neuralgia, or nerve pain, is a frustrating condition that can occur due to nerve irritation, damage, or ongoing conditions like sciatica and trigeminal neuralgia. St. John’s wort is particularly beneficial for the terribly sharp, shooting pains commonly associated with neuralgia and is helpful for when these pains become burning sensations and an area of the body is horribly hypersensitive.

St. John’s wort’s compounds help reduce inflammation in the nerves and promote blood circulation, which can ease pain and support the healing process. St. John’s wort is analgesic (pain-relieving) and anti-inflammatory, so it makes a strong ingredient in topical creams and salves. To make the oil, infuse the flowers of St. John’s wort in a carrier oil, such as olive or sunflower oil, for several weeks, preferably on a sunny windowsill in a glass jar placed over a plate in case the oil oozes. The resulting red oil can be massaged into areas experiencing pain or tingling, providing local relief.

To make a salve from this oil, be sure you’re using olive oil or another thick oil (sunflower is generally too thin); for every 1 cup of oil, add ¼ cup chopped beeswax. Heat them together until the beeswax melts. Pour into 2-oz jars and add 20-30 drops of essential oils if desired. For nerve pain and topical nerve damage, consider balsam or lavender.

St. John’s wort for Shingles

Typically but not always experienced by older individuals, shingles or herpes zoster is the result of being exposed to the chicken pox virus, Varicella zoster. The virus can lay dormant in the body and “erupt” at any time and is not restricted to the elderly: in fact, both my children had shingles in their teens. Shingles irritates nerves and causes a painful, itchy and frustrating rash of blisters, often on the back but sometimes around the eyes, and these are highly contagious.

St. John’s wort is specific (in my Formulary Theory, it is a Tier 2 Specific) for the symptoms of shingles and can be applied topically as an oil directly to shingles blisters. Other herbs have emollient effects and can be used simultaneously with St. John’s wort, including red clover, violet leaf and flower, yarrow, rose petal, calendula, and plantain. If making an infused oil, you can combine these herbs (slightly wilted) in a jar and infuse them together, or you can infuse them all separately and add them together later.

St. John’s wort for Tingling and Numbness

Tingling or numbness in the limbs, often described as “pins and needles,” can arise from nerve compression, inflammation, or poor circulation. St. John’s wort is helpful in reducing tingling sensations by promoting blood flow and reducing nerve inflammation. If you’ve just stood up from a crouched or seated position and feel “pins and needles,” you likely don’t need an herbal remedy—you need bodily movement.

But for chronic or ongoing nerve tingling and numbness, a topical application of Hypericum can be beneficial. Apply the herb-infused oil topically to the affected area to stimulate circulation and soothe irritated nerve endings. Or, take St. John’s wort internally as a tincture or capsule for whole-body nerve support, improving blood flow and reducing sensations of tingling.

Other herbs to consider for “cold hands cold feet” include hawthorn, garlic, ginger, prickly ash, and other vasodilators. Be aware of contraindications with blood pressure medicine when using vasodilators, as many of these will lower blood pressure.

Dosage and How to Take St. John’s Wort 

St. John’s wort is available in many forms, including capsules, tinctures, teas, and oils. In my opinion, it’s not especially delicious as a tea but it can be added to other herbs that provide a more flavorful tea (such as spearmint, hibiscus, ginger, stinging nettle, or lemongrass.)

For mild to moderate depression, you want to embark on a routine of consistent, daily use at a fairly high dose. A common dosage recommendation is 300 mg of standardized extract taken three times daily, for a total of 900 mg per day. This dosage is based on a standardized extract containing 0.3% hypericin, what scientists consider the “active compound.”

A home-made tincture for internal use should be made with high-quality ethyl alcohol such as vodka or Everclear using the flowers and buds. If using fresh plant material, fill a glass jar full, smash down the flowers, and keep filling until you can no longer fit material in. Pour in the alcohol, put the lid on, label the jar (with plant, plant part, date, and menstruum (the liquid). Put the jar on a plate in a sunny window and let it sit for 3-to-6 months, shaking occasionally. Strain the plant material out and bottle the liquid. This is your tincture. Home-made tinctures are likely to be less potent than those processed at herbal facilities.

It can take a few weeks to experience the full benefits of St. John’s wort, so consistency is key. Be aware of contraindications (some say to avoid sunlight exposure) and be aware that St. John’s wort interacts with several medications, especially pharmaceutical SSRIs.

Be aware: Do not take St. John’s wort if you’re already taking SSRI medications unless you’re working closely with a physician because this can lead to serotonin syndrome, a very dangerous consequence of too much serotonin in the brain.

Herbs for the Brain Online Course

If you’re a beginner, or someone curious about this topic and you want to support yourself or loved ones, check out our Herbs for the Brain Beginner online course, which will provide you a solid overview, a look at dozens of herbs and foods, and a 24-recipe e-book to help you create an action plan.

If you are a professional, our Herbs for the Brain Certificate Course provides 13 CEUs and CH (Contact Hours) for nurses and acupuncturists as well as AHG RH hours for herbalists. The course is specially designed for these professions as well as social workers, aromatherapist, and caregivers seeking a diving deep into botanical and nutrient-based therapies for herbal and mental health. The course includes a Student Workbook, Student Coursebook, learning objectives, and up-to-date scientific and research-based case studies.