Oregano

Research corpus coverage

Chemistry notes

• CHEMISTRY: Relevant reported constituents include carvacrol; thymol; rosmarinic acid; constituent presence alone does not establish clinical efficacy.

Traditional / historical use

Documented traditional use — not a claim of established efficacy.

• TRADITIONAL: Oregano has been used for digestive and respiratory complaints; topical antimicrobial use; this records historical/traditional use and does not establish efficacy.

  MODERATE · regulatory monograph · WHO Monographs on Selected Medicinal Plants

Modern evidence

• EVIDENCE: For the major use set (digestive and respiratory complaints; topical antimicrobial use), the evidence assessment is insufficient: Insufficient clinical evidence; antimicrobial findings are mostly in vitro.

  LOW · regulatory monograph and mixed scientific literature · WHO Monographs on Selected Medicinal Plants

Forms used traditionally

A listed form does not imply it suits every plant part, or that one preparation is interchangeable with another — see the plant’s own notes below.

Cats

• Caution

  The steam-distilled oregano essential oil was characterized as safe for cats only up to a calculated maximum feed concentration; cats received an additional uncertainty factor because of their unusually low capacity for glucuronidation. No cat-specific adverse signs were reported.

  Intrinsic toxicity · ORAL · steam-distilled essential oil incorporated into complete feed · HIGH · regulatory_guidance · Safety and efficacy of an essential oil from Origanum vulgare ssp ...

Dogs

• Caution

  The steam-distilled oregano essential oil was not established as safe for dogs at the proposed complete-feed use level; no dog-specific tolerance or toxicological studies were submitted. No dog-specific adverse signs were reported.

  Intrinsic toxicity · ORAL · steam-distilled essential oil incorporated into complete feed · HIGH · regulatory_guidance · Safety and efficacy of an essential oil from Origanum vulgare ssp ...

• Caution

  Greek oregano (Origanum vulgare hirtum) is listed under “Plants Toxic to Dogs.” No cat-specific evidence, toxic constituents, clinical signs, or preparation distinctions are provided.

  Intrinsic toxicity · UNKNOWN · Not stated; whole plant or plant group listing only · HIGH · poison_control_database · Toxic and Non-Toxic Plant List — Dogs - ASPCA

Additional safety notes (general, unstructured)

Free-text safety notes carried from their source — not broken out by species, route, or hazard type, and not equivalent to the structured records above. Each note names the kind of source it came from.

• SAFETY: Major issues include Concentrated oil irritant; allergy possible. Contraindications/cautions include Lamiaceae allergy.

  MODERATE · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements

• SAFETY: Clinically relevant interaction concerns include Potential additive anticoagulant and glucose-lowering effects.

  MODERATE · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements

  Some interactions are theoretical or based on case reports/pharmacokinetics rather than outcome trials.

• SAFETY: Pregnancy/lactation reference: Insufficient medicinal-dose pregnancy/lactation evidence.

  MODERATE · regulatory monograph or evidence synthesis · WHO Monographs on Selected Medicinal Plants

  Absence of evidence is not evidence of safety.

• The steam-distilled oregano essential oil was characterized as safe for cats only up to a calculated maximum feed concentration; cats received an additional uncertainty factor because of their unusually low capacity for glucuronidation. No cat-specific adverse signs were reported.

  HIGH · regulatory_guidance · Safety and efficacy of an essential oil from Origanum vulgare ssp ...

  The page contains a discrepancy between the stated calculated maximum safe concentration in the abstract/conclusions and the visibly displayed Table 3 value.

• The steam-distilled oregano essential oil was not established as safe for dogs at the proposed complete-feed use level; no dog-specific tolerance or toxicological studies were submitted. No dog-specific adverse signs were reported.

  HIGH · regulatory_guidance · Safety and efficacy of an essential oil from Origanum vulgare ssp ...

• Greek oregano (Origanum vulgare hirtum) is listed under “Plants Toxic to Dogs.” No cat-specific evidence, toxic constituents, clinical signs, or preparation distinctions are provided.

  HIGH · poison_control_database · Toxic and Non-Toxic Plant List — Dogs - ASPCA

  The listed taxon is a cultivar or subspecific form of Origanum vulgare, not the canonical species wording exactly; no essential-oil evidence is provided.

Taxonomic identity note

• Oregano is treated here as Origanum vulgare L. in the family Lamiaceae; recorded older names include Origanum creticum L..