Herbs (Global Traditional) · European
Hypericum perforatum
Strong Evidencebotanical
Hermetica Superfood Encyclopedia
Hypericum perforatum (St. John's wort) contains hypericin and hyperforin as key bioactive compounds that inhibit neurotransmitter reuptake. The herb demonstrates moderate antidepressant effects through serotonin, norepinephrine, and dopamine pathway modulation.
Hypericum perforatum (St. John's wort) is a perennial herb native to Europe, Asia, and North Africa, now found globally, belonging to the Hypericaceae family. It is sourced from aerial parts, primarily flowers and leaves, with active compounds extracted using hydroalcoholic methods (ethanol/methanol) or water for teas and infusions. The plant contains naphthodianthrones (hypericin), phloroglucinols (hyperforin), flavonoids, and phenolic acids as its primary bioactive constituents.
The research dossier references documented pharmacological activities including antidepressant effects from prior reviews (PubMed PMID: 11370698), but lacks specific details on key human clinical trials, RCTs, or meta-analyses. No comprehensive trial data, sample sizes, or specific outcomes for conditions like depression treatment are provided in the available results.
The research does not specify clinically studied dosage ranges for extracts, powders, or standardized forms. Standardization details used in studies (such as 0.3% hypericin content) are mentioned but without corresponding dosage recommendations. Consult a healthcare provider before starting any new supplement.
Hypericum perforatum (St. John's Wort) is not consumed as a food for macronutrient value; it is used as a medicinal herb. Its significance lies entirely in its bioactive phytochemical profile. Key compounds include: • **Hypericin** (a naphthodianthrone): ~0.05–0.3% of dried herb weight; primary marker compound, photosensitizing agent, implicated in antidepressant and antiviral activity. • **Pseudohypericin**: typically present at 2–4× the concentration of hypericin (~0.1–0.6% dry weight); similar naphthodianthrone with comparable bioactivity. • **Hyperforin** (a phloroglucinol derivative): ~2–5% of dried herb in high-quality specimens; considered the principal antidepressant constituent via inhibition of serotonin, dopamine, norepinephrine, GABA, and glutamate reuptake. Highly lipophilic and unstable (degrades with light/oxygen exposure, reducing bioavailability). • **Adhyperforin**: ~0.2–1.5% dry weight; structural analog of hyperforin with similar but less potent activity. • **Flavonoids**: including rutin (~1.6%), hyperoside (hyperin, ~0.5–1.0%), isoquercitrin (~0.3%), quercitrin (~0.3%), quercetin (~0.1–0.3%), and amentoflavone (a biflavonoid, trace amounts); contribute antioxidant and potential MAO-inhibiting activity. Total flavonoid content approximately 2–4% dry weight. • **Procyanidins (condensed tannins)**: ~5–12% dry weight; oligomeric proanthocyanidins that may modulate bioavailability of other constituents. • **Phenolic acids**: including chlorogenic acid (~0.5–1.0%) and caffeic acid (trace). • **Essential oil** (trace, ~0.1–0.3%): contains α-pinene, β-pinene, myrcene, limonene, and caryophyllene. • **Xanthones**: ~0.01–0.1% including 1,3,6,7-tetrahydroxyxanthone. • **Vitamins and minerals**: Not a significant source; negligible amounts of vitamins C and A precursors; trace minerals (calcium, magnesium, iron, zinc) present but not at nutritionally relevant levels given typical dosing (300–900 mg extract/day). • **Bioavailability notes**: Hypericin has poor aqueous solubility and oral bioavailability estimated at ~14–21%; peak plasma levels reached in 4–6 hours with a long half-life (~24–48 hours). Hyperforin is lipophilic with moderate oral absorption but is highly unstable — standardized extracts often use CO₂ extraction or stabilization with salts (e.g., dicyclohexylammonium hyperforinate) to preserve content. Hyperforin is a potent inducer of CYP3A4, CYP2C9, CYP1A2, and P-glycoprotein via PXR activation, significantly affecting the metabolism and bioavailability of co-administered pharmaceuticals. Procyanidins may reduce absorption of hypericin and hyperforin if taken in crude herb form versus standardized extracts. Standardized extracts are typically normalized to 0.3% hypericin and/or 3–5% hyperforin.
Hypericin and hyperforin in St. John's wort inhibit the reuptake of serotonin, norepinephrine, and dopamine by blocking their respective transporters. Hyperforin also modulates GABA and glutamate neurotransmission while inhibiting cortisol release through hypothalamic-pituitary-adrenal axis suppression. Additional mechanisms include weak MAO-A and MAO-B enzyme inhibition.
Meta-analyses of randomized controlled trials show St. John's wort extracts (300-1800mg daily) demonstrate superior efficacy to placebo for mild to moderate depression. Studies involving over 5,000 participants indicate response rates of 60-70% compared to 35-40% with placebo. The evidence quality is moderate, with most trials lasting 4-12 weeks using standardized extracts containing 0.3% hypericin. Effectiveness appears comparable to conventional antidepressants for mild depression but with fewer side effects.
St. John's wort induces cytochrome P450 enzymes (CYP3A4, CYP1A2), significantly reducing the effectiveness of numerous medications including birth control pills, warfarin, and immunosuppressants. Common side effects include photosensitivity, gastrointestinal upset, dizziness, and fatigue occurring in 10-15% of users. Serotonin syndrome risk exists when combined with SSRIs or other serotonergic medications. Pregnancy and breastfeeding safety has not been established, making it inadvisable for use during these periods.
