Supplement · herbal

St. John's Wort

Quick read: St.

Quick facts · Liquid Extract / Tincture

Dose: 1 ml
Per day: 3 ml
Timing: 3 times a day
Course: 90 days + break 45 days
Strongest effect: Anxiety ReductionHighClinical

Scientific background

St. John's Wort (scientific name: Hypericum perforatum L.) is a perennial flowering plant whose extracts are widely utilized as a botanical supplement. Biochemically, it comprises a complex mixture of active constituents, including naphthodianthrones (e.g., hypericin), phloroglucinols (e.g., hyperforin), and various flavonoids (e.g., hyperoside, rutin, quercetin). Historically employed in traditional medicine for diverse ailments, its primary physiological role in modern context revolves around supporting nervous system function and mood regulation. The main mechanism of action is attributed to hyperforin, which non-selectively inhibits the reuptake of neurotransmitters such as serotonin, norepinephrine, dopamine, GABA, and glutamate by interacting with synaptic transporter proteins. This action elevates neurotransmitter concentrations in the synaptic cleft, potentially improving neuronal communication. While hypericin's role is less direct, it may contribute by influencing monoamine oxidase activity or other pathways. Flavonoids further offer antioxidant and anti-inflammatory benefits. Clinically, St. John's Wort extracts, particularly those standardized for hyperforin, have been extensively researched for their efficacy in managing mild to moderate depressive symptoms, often demonstrating comparable outcomes to conventional antidepressants in these specific contexts. Research continues to explore its broader neuroprotective and anti-inflammatory properties. Due to significant potential for drug-drug interactions, particularly via cytochrome P450 enzyme induction, professional medical consultation is advised prior to supplementation.

Form & dosage

Single dose: 1 ml
Daily: 3 ml
Course: 90 days
Break: 45 days
Timing: 3 times a day

How we rate evidence

Probability — how likely the effect is to show up

Very high
High
Medium
Low

Evidence — where the data comes from

Scientific Meta-analyses and randomized trials
Clinical Clinical trials and practice
Animal research Animal studies
People reports User reports and anecdotes
Theoretical Mechanistic reasoning, not yet tested

Effects

High probability(4)

Antidepressant Effectpsychetheoretical
St. John's Wort helps alleviate symptoms of mild to moderate depression by influencing neurotransmitters like serotonin, norepinephrine, and dopamine, leading to a noticeable uplift in mood for most users over several weeks.
Analgesic Effecthealthpeople_reports
When applied topically, St. John's Wort oil or cream is widely used to provide localized relief from nerve pain, muscle aches, and minor skin irritations due to its soothing properties.
Mood Improvementpsychetheoretical
By modulating brain chemistry, particularly neurotransmitter levels, this supplement enhances overall emotional well-being, fostering a more positive and stable mood with consistent use.
Anxiety Reductionpsycheclinical
St. John's Wort contributes to a sense of calm by supporting balanced neurotransmitter activity, effectively reducing feelings of restlessness and inner tension for many individuals experiencing anxiety.

Medium probability(7)

Fatigue Reductionpsychepeople_reports
For those experiencing fatigue linked to mood disturbances, St. John's Wort can help restore energy levels and mental vigor as it addresses the underlying emotional imbalances.
Antioxidant Protection Enhancementhealththeoretical
Rich in flavonoids and other phenolic compounds, St. John's Wort provides antioxidant support, helping to neutralize free radicals and protect cells from oxidative damage throughout the body.
Inflammation Reductionhealththeoretical
The herb possesses compounds that exhibit anti-inflammatory properties, potentially contributing to a reduction in systemic inflammatory responses and supporting overall cellular health over time.
Neuroprotective Effecthealthanimal_research
Through its antioxidant and anti-inflammatory actions, St. John's Wort demonstrates neuroprotective potential in studies, helping to shield brain cells from damage and support long-term neurological health.
Improving neuroplasticitymindtheoretical
St. John's Wort may support the brain's natural ability to reorganize and form new connections, a process vital for learning, memory, and sustained improvements in mood and cognitive flexibility.
Sleep Quality Improvementpsychepeople_reports
Often as an indirect result of improved mood and reduced anxiety, St. John's Wort can lead to more restful and restorative sleep, helping users wake up feeling more refreshed.
Stress Resilience Improvementpsycheclinical
Through its influence on the body's stress response pathways, St. John's Wort can enhance your ability to cope with daily stressors, promoting greater emotional stability and less reactivity.

Side effects

Medium probability(3)

Increased Photosensitivitybodytheoretical
St. John's Wort contains hypericin, which can make your skin more sensitive to sunlight. This means you might get sunburned more easily, even with moderate exposure, so it's wise to be extra careful in the sun while taking this supplement.
Digestive Discomforthealthclinical
General stomach upset, including feelings of heaviness, mild abdominal pain, or a sense of unease in the gut, can occur as your body adjusts to St. John's Wort.
Nauseahealthclinical
Some users experience a feeling of sickness or an urge to vomit, especially when first starting St. John's Wort or if taken on an empty stomach. This digestive discomfort usually subsides with continued use.

Low probability(10)

Dry Mouth (Xerostomia)bodyclinical
Some individuals report a sensation of dryness in the mouth due to St. John's Wort's effect on neurotransmitters, which can influence salivary gland function.
Increased Anxietypsycheclinical
While often taken for anxiety, paradoxically, some sensitive individuals may experience an initial increase in nervousness or agitation when starting St. John's Wort, which typically resolves.
Nervousness and Restlessnesspsycheclinical
A feeling of inner tension or inability to sit still, often described as 'jitters,' can sometimes accompany the initial stimulating effects of St. John's Wort.
Mental Fatiguepsychepeople_reports
A feeling of mental exhaustion or 'brain fog,' where thoughts feel unclear or difficult to organize, is sometimes reported. This is a subjective experience that tends to improve over time.
Diarrheahealthclinical
Looser or more frequent bowel movements can be a gastrointestinal side effect, often occurring at the start of supplementation. It's usually mild and temporary.
Constipationhealthclinical
Some users may experience difficulty with bowel movements or hardened stools, which is another common, though less frequent, gastrointestinal side effect of St. John's Wort.
Decreased Libidopsycheclinical
Like some pharmaceutical antidepressants, St. John's Wort can occasionally lead to a reduction in sex drive, a side effect linked to its influence on serotonin pathways.
Headachehealthclinical
Headaches are a fairly common side effect reported by some individuals when taking St. John's Wort. They are typically mild and transient, often diminishing as your body adapts.
Insomniapsycheclinical
Despite its use for sleep issues, St. John's Wort can sometimes cause difficulty falling or staying asleep, especially if taken too late in the evening due to its mild stimulating properties.
Dizzinessmindclinical
A feeling of lightheadedness or unsteadiness can occur, particularly when first starting the supplement. It's usually mild and resolves as your body adjusts.

Low probability(1)

Increased Liver Loadhealththeoretical
St. John's Wort is primarily metabolized by the liver, and in rare cases, especially with high doses or prolonged use, it may increase the workload on the liver, potentially elevating liver enzyme levels. This is why liver monitoring might be advised for long-term use.