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Omnia Sana · Plant Monograph

Bay-leaf willowherb

Epilobium parviflorum

Family OnagraceaeParts used Aerial parts (herb)Also known as Small-flowered willowherb, Hoary willowherb

This monograph compiles 3 documented constituents, 3 pharmacological actions, 8 traditional / indicated uses, supported by 6 cited sources, drawn directly from the Omnia Sana plant database.

Key Constituents

Macrocyclic ellagitannins (notably oenothein B)[4, 5]

Characteristic Epilobium polyphenols underlying the anti-inflammatory and prostate activity; a genus review identifies oenothein B as the dominant constituent and likely driver of the antimicrobial, anti-inflammatory, anti-proliferative and antioxidant effects.

TanninsPhenolic compounds
Flavonoids (myricetin and quercetin glycosides)[4]

Antioxidant constituents.

FlavonoidsGlycosidesQuercetin
Plant sterols (beta-sitosterol)[4]

Sterols associated with benign prostatic hyperplasia support.

Phytosterols

Pharmacological Actions

Anti-inflammatory[4]

Anti-inflammatory (inhibits COX-1 and COX-2 prostaglandin synthesis)

Antimicrobial[4]

Antibacterial, including against Escherichia coli (urinary support)

Antioxidant[4]

Antioxidant (hydroxyl-radical scavenging)

Traditional & Indicated Uses

Arthritis / joint pain[4]Traditional · 1/10

inferred from anti-inflammatory action

more plants for arthritis / joint pain →detailed sources →
Infection (general)[4]Traditional · 1/10

inferred from antimicrobial action

more plants for infection (general) →detailed sources →
Inflammation (general)[4]Traditional · 1/10

inferred from anti-inflammatory action

more plants for inflammation (general) →detailed sources →
Prostate support[4, 5, 6]Moderate · 5/10

Supports lower urinary tract symptoms of benign prostatic hyperplasia (prostate support) - a genus Epilobium review notes traditional BPH use attributed mainly to oenothein B, though clinical evidence is not yet conclusive

more plants for prostate support →detailed sources →
Skin irritation[4]Traditional · 1/10

inferred from anti-inflammatory action

more plants for skin irritation →detailed sources →
Urinary support[4, 5, 6]Moderate · 5/10

Antibacterial, including against Escherichia coli (urinary support); Supports lower urinary tract symptoms of benign prostatic hyperplasia (prostate support) - a genus Epilobium review notes traditional BPH use attributed mainly to oenothein B, though clinical evidence is not yet conclusive

more plants for urinary support →detailed sources →
Urinary tract infection (UTI)[4, 5, 6]Moderate · 5/10

Supports lower urinary tract symptoms of benign prostatic hyperplasia (prostate support) - a genus Epilobium review notes traditional BPH use attributed mainly to oenothein B, though clinical evidence is not yet conclusive

more plants for urinary tract infection (uti) →detailed sources →
Wounds[4]Traditional · 1/10

inferred from antimicrobial action

more plants for wounds →detailed sources →

Safety, Cautions & Contraindications

Safety note[6]Info

Lower urinary tract / prostate symptoms must be medically assessed first to exclude prostate cancer; willowherb is a supportive measure, not a substitute for diagnosis and treatment.

Safety note[6]Info

Well tolerated over three months in clinical use; longer-term safety data are limited.

References

REF-0803, REF-0804, REF-0805

References & Sources

  1. Vitalone, A. and Allkanjari, O (2018) 'Epilobium spp: Pharmacology and Phytochemistry', Phytotherapy Research, 32(7), pp. 1229-1240. doi:10.1002/ptr.6072 Traditional / reference
    https://doi.org/10.1002/ptr.6072
  2. Cicero, A.F.G., Allkanjari, O., Busetto, G.M., Cai, T. et al (2019) 'Nutraceutical treatment and prevention of benign prostatic hyperplasia and prostate cancer', Archivio Italiano di Urologia e Andrologia, 91(3), pp. 139-152. doi:10.4081/aiua.2019.3.139 Traditional / reference
    https://doi.org/10.4081/aiua.2019.3.139
  3. Vlase, A.M., Toiu, A., Gligor, O., Muntean, D. et al (2024) 'Investigation of Epilobium hirsutum L. Optimized Extract's Anti-Inflammatory and Antitumor Potential', Plants (Basel), 13(2), pp. 198. doi:10.3390/plants13020198 Preclinical
    https://doi.org/10.3390/plants13020198
  4. Steenkamp, V., Gouws, M.C., Gulumian, M., Elgorashi, E.E. and van Staden, J (2005) 'Studies on antibacterial, anti-inflammatory and antioxidant activity of herbal remedies used in the treatment of benign prostatic hyperplasia and prostatitis', Journal of Ethnopharmacology, pp. 2005. doi:10.1016/j.jep.2005.07.007 Traditional / reference
    https://doi.org/10.1016/j.jep.2005.07.007
  5. Granica, S., Piwowarski, J.P., Czerwinska, M.E. and Kiss, A.K (2014) 'Phytochemistry, pharmacology and traditional uses of different Epilobium species (Onagraceae): a review', Journal of Ethnopharmacology, pp. 316--346. doi:10.1016/j.jep.2014.08.036 Traditional / reference
    https://doi.org/10.1016/j.jep.2014.08.036
  6. Coulson, S., Rao, A., Beck, S.L., Steels, E., Gramotnev, H. and Vitetta, L (2013) 'A phase II randomised double-blind placebo-controlled clinical trial investigating the efficacy and safety of ProstateEZE Max: a herbal medicine preparation (containing Epilobium parviflorum) for the management of symptoms of benign prostatic hypertrophy', Complementary Therapies in Medicine. doi:10.1016/j.ctim.2013.01.007 Randomized trial
    https://doi.org/10.1016/j.ctim.2013.01.007

Record last updated 2026-06-20 · Provenance: website+pubmed+symptom-tool · Status: verified

This fact sheet is generated automatically from the Omnia Sana plant database and reflects its latest synced data. It is provided for educational purposes only and is not medical advice. Always consult a qualified practitioner before using medicinal plants.

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