Hypericin
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Chemical Class | Naphthodianthrone (photosensitising anthraquinone derivative) |
| Molecular Formula / CAS | C₃₀H₁₆O₈ · CAS 548-04-9 |
| Primary Botanical Source(s) | St. John's wort (Hypericum perforatum) |
| Plant Part | Flowering tops |
| Typical Content | One of the characteristic marker constituents of St. John’s wort extract, alongside pseudohypericin and hyperforin |
| Solubility / Format | Available within standardised extract powders and liquid extracts, quantified as part of total hypericin content |
| Sourcing Status | Product-live — genuine match via Herbuno’s St. John’s wort extract line |
| Buy from Herbuno | St John’s Wort Extract Powder (0.3% Hypericin) · St John’s Wort Extract Powder |
Name origin: Hypericin takes its name from Hypericum, the genus of St. John's wort, from whose flowers the compound was first isolated. Traditional use: St. John's wort has a documented European traditional-medicine history stretching back to antiquity, used topically for wound healing and burns and internally as a folk remedy for nervous complaints, with the plant’s name itself referencing St. John the Baptist, as the flowers traditionally bloom around the feast day of St. John. Research trajectory: Hypericin was initially considered the primary active antidepressant constituent of St. John’s wort extract when clinical research into the plant accelerated through the 1980s–90s, particularly in Germany, where standardised extract became a widely used treatment for mild-to-moderate depression; subsequent research has complicated this picture, identifying hyperforin and various flavonoids as also contributing meaningfully to the plant’s antidepressant activity, while hypericin’s own research focus has shifted substantially toward its distinctive photosensitising and photodynamic properties. Commercial source: St. John’s wort flowering tops are the standard commercial source of hypericin, and Herbuno’s standardised extracts, including one specifically quantified to 0.3% hypericin, reflect this well-established, genuine botanical match.
Evidence for Hypericin Applications
Hypericin belongs to the naphthodianthrone class of compounds and has historically served as the standardisation marker for commercial St. John’s wort extract, though modern research attributes the plant’s antidepressant activity to a combination of constituents rather than hypericin alone: a mechanistic review describes hypericin, hyperforin and several flavonoids as jointly contributing to St. John’s wort’s antidepressant effects, with proposed mechanisms including modulation of hypothalamic-pituitary-adrenal axis gene regulation (Butterweck 2003). Claim strength: Moderate.
Hypericin’s most distinctive and well-documented property is photosensitisation. A placebo-controlled randomised clinical trial specifically measuring dermal photosensitivity after high-dose St. John’s wort extract found measurable increases in skin photosensitivity correlated with plasma hypericin and pseudohypericin concentrations, directly confirming in humans a phototoxic effect previously established in cell culture and animal studies (Brockmoller et al. 1997). This remains one of the most well-established human safety findings anywhere in the HerbIQ index for a compound at normal supplemental exposure. Claim strength: High (safety).
In-vitro photochemical characterisation of St. John’s wort’s major constituents identified hypericin, pseudohypericin and hyperforin specifically as the compounds responsible for the extract’s phototoxic potential, generating reactive oxygen species and photosensitised lipid peroxidation under light exposure (Onoue et al. 2011). Separate research has extended this phototoxicity concern to ocular tissue, with hypericin exposure combined with UV-A or visible light shown to promote necrosis and apoptosis in human lens and retinal pigment epithelial cells in laboratory studies, raising a documented theoretical concern for eye tissue with high, sustained exposure. Claim strength: Moderate.
Separately, hypericin’s photosensitising property has itself become an active area of research in an entirely different application: photodynamic therapy, where hypericin’s selective uptake by tumour cells and photoactivation under controlled light exposure has been investigated as an experimental cancer treatment approach, including in melanoma cell models. This represents a deliberate therapeutic use of the same photochemical property that is a safety concern in the context of oral supplementation. Claim strength: Emerging.
For formulators, the practical implication is that hypericin content, rather than being purely a marker of antidepressant potency, is directly tied to photosensitivity risk, and clinical guidance consistently recommends that individuals taking St. John’s wort extract, particularly at higher doses, avoid excessive sun or UV exposure and use appropriate sun protection. This should be reflected clearly in product labelling for any hypericin-standardised extract. Claim strength: High (safety).
Dosage & Formulator Specification
Traditional standardised St. John’s wort extract has commonly been dosed at 300 mg three times daily (900 mg/day total) of extract standardised to 0.3% hypericin in the depression research literature, though modern reformulation increasingly emphasises hyperforin content alongside or instead of hypericin as the more mechanistically relevant marker.
Analytical quantification of hypericin is performed by HPLC, and because hypericin and pseudohypericin co-occur and are sometimes reported together as “total hypericins,” formulators should confirm whether a supplier’s stated percentage refers to hypericin specifically or to the combined total, since the two figures are not interchangeable.
Given hypericin’s well-documented photosensitising activity, finished products containing standardised St. John’s wort extract should carry clear sun-exposure caution labelling, particularly for higher-dose formulations, and formulators should be aware this risk scales with hypericin content and dose rather than being a fixed, dose-independent property.
Regulatory positioning for hypericin-standardised St. John’s wort extract follows established botanical antidepressant-adjacent supplement precedent in most markets, with recognised traditional-use monograph status in several European regulatory frameworks; formulators should also account for St. John’s wort’s well-documented drug interaction profile via cytochrome P450 and P-glycoprotein induction, a separate consideration from the photosensitivity risk discussed above.
Frequently Asked Questions — Hypericin
This is attributed specifically to hypericin, a naphthodianthrone compound that absorbs UV and visible light and generates reactive oxygen species in skin tissue when activated by light exposure. A placebo-controlled human trial confirmed this phototoxic effect correlates directly with plasma hypericin concentration.
No. While hypericin was historically used as the standardisation marker and initially thought to be the primary antidepressant constituent, modern research attributes St. John’s wort’s effects to a combination of hypericin, hyperforin and various flavonoids acting together.
Clinical guidance generally recommends that people taking St. John’s wort extract, particularly at higher doses, avoid excessive sun or UV exposure and use appropriate sun protection, given hypericin’s well-documented and dose-related photosensitising activity confirmed in human trials.
Yes. Hypericin’s photosensitising property, the same one responsible for its sun-sensitivity side effect, is being investigated separately in photodynamic cancer therapy research, where controlled light activation of hypericin taken up by tumour cells is used experimentally to target cancer cells, including in melanoma models.
Related compounds: Berberine, 5-Hydroxytryptophan (5-HTP)