Rosmarinic Acid
Research reviewed: Up until 03/2026
Rosmarinic Acid (Rosmarinic acid (alpha-o-caffeoyl-3,4-dihydroxyphenyllactic acid)) is a dietary supplement with 10 published peer-reviewed studies involving 168 participants, researched for Allergy & Asthma, Neuroprotection & Cognition, Anti-inflammatory & Antioxidant and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Allergy & Asthma
ModerateNeuroprotection & Cognition
ModerateAnti-inflammatory & Antioxidant
ModerateReviews & Bioavailability
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Allergy & Asthma
To evaluate rosmarinic acid supplementation on seasonal allergic rhinoconjunctivitis symptoms.
Study Type
Randomised double-blind placebo-controlled
Purpose
To evaluate rosmarinic acid supplementation on seasonal allergic rhinoconjunctivitis symptoms.
Dose
200 mg rosmarinic acid daily
Participants
30 adults with seasonal allergic rhinitis
Duration
4 weeks
Results
Rosmarinic acid significantly reduced total nasal symptom score (-37%), ocular symptom score, and nasal eosinophil count vs placebo.
How They Measured It
Nasal symptom score, ocular symptom score, eosinophil count in nasal lavage
To assess rosmarinic acid supplementation for allergic asthma management.
Study Type
Randomised placebo-controlled pilot
Purpose
To assess rosmarinic acid supplementation for allergic asthma management.
Dose
100-200 mg rosmarinic acid daily
Participants
27 adults with mild-moderate allergic asthma
Duration
8 weeks
Results
Significant improvement in FEV1 (+9%) and reduction in exhaled NO (-28%); sputum eosinophils reduced vs placebo.
How They Measured It
FEV1, FVC, peak expiratory flow, exhaled NO, eosinophils in induced sputum
To investigate rosmarinic acid's inhibition of the Complement C5a-mediated allergic inflammatory cascade.
Study Type
In vitro mechanistic study
Purpose
To investigate rosmarinic acid's inhibition of the Complement C5a-mediated allergic inflammatory cascade.
Dose
5-100 µM rosmarinic acid
Participants
Human neutrophils and mast cell line (RBL-2H3)
Duration
Acute assay
Results
Rosmarinic acid potently inhibited C5a-induced neutrophil migration and IgE-mediated histamine release from mast cells; mechanism involves complement inhibition.
How They Measured It
C5a-induced neutrophil migration, complement assay, histamine release from mast cells
Neuroprotection & Cognition
To evaluate rosmarinic acid on Alzheimer's disease pathology and cognitive function.
Study Type
Animal study
Purpose
To evaluate rosmarinic acid on Alzheimer's disease pathology and cognitive function.
Dose
50-100 mg/kg rosmarinic acid
Participants
APP/PS1 transgenic Alzheimer's mice
Duration
3 months
Results
Rosmarinic acid significantly improved spatial memory, reduced amyloid-beta deposition (-50%), and normalised inflammatory cytokine levels in hippocampus.
How They Measured It
Morris water maze; hippocampal Abeta levels; tau phosphorylation; neuroinflammation
To evaluate rosmarinic acid supplementation on cognitive function and mood in mild cognitive impairment.
Study Type
RCT
Purpose
To evaluate rosmarinic acid supplementation on cognitive function and mood in mild cognitive impairment.
Dose
200 mg rosmarinic acid daily
Participants
50 adults with mild cognitive impairment
Duration
16 weeks
Results
Significant improvements in verbal learning and memory tests; mood disturbance (POMS) and anxiety scores reduced vs placebo.
How They Measured It
MMSE, digit span, Rey Auditory Verbal Learning Test, POMS
Anti-inflammatory & Antioxidant
To assess rosmarinic acid supplementation on systemic inflammation markers in healthy adults.
Study Type
RCT
Purpose
To assess rosmarinic acid supplementation on systemic inflammation markers in healthy adults.
Dose
150 mg rosmarinic acid daily
Participants
44 healthy adults
Duration
8 weeks
Results
Significant reductions in hs-CRP (-24%) and IL-6 (-20%) and improvement in total antioxidant status vs placebo.
How They Measured It
Serum hs-CRP, IL-6, TNF-alpha, total antioxidant status
To characterise the molecular antioxidant and anti-inflammatory mechanisms of rosmarinic acid.
Study Type
In vitro mechanistic study
Purpose
To characterise the molecular antioxidant and anti-inflammatory mechanisms of rosmarinic acid.
Dose
1-50 µM rosmarinic acid
Participants
Multiple cell lines (HepG2, RAW264.7, HEK293)
Duration
24-48 hours
Results
Rosmarinic acid exhibited high ORAC activity; suppressed NF-kB and AP-1 transcription factors; activated Nrf2/HO-1 cytoprotective pathway.
How They Measured It
DPPH, ORAC; NF-kB, AP-1 pathway analysis; Nrf2/HO-1 activation
To evaluate rosmarinic acid's anti-arthritic effects in a rat model of rheumatoid arthritis.
Study Type
Animal study
Purpose
To evaluate rosmarinic acid's anti-arthritic effects in a rat model of rheumatoid arthritis.
Dose
25-100 mg/kg rosmarinic acid
Participants
CIA rat model
Duration
4 weeks
Results
Rosmarinic acid significantly reduced paw oedema, joint pathology, and serum inflammatory cytokines; comparable effect to low-dose methotrexate at highest dose.
How They Measured It
Paw oedema, joint histopathology, serum TNF-alpha, IL-1beta, anti-CII antibody
Reviews & Bioavailability
To characterise rosmarinic acid absorption and pharmacokinetics from rosemary extract supplement.
Study Type
Bioavailability study
Purpose
To characterise rosmarinic acid absorption and pharmacokinetics from rosemary extract supplement.
Dose
500 mg rosemary extract (50 mg rosmarinic acid)
Participants
12 healthy adults
Duration
Single dose and 4-week
Results
Rosmarinic acid bioavailability ~30%; peak plasma at 1-1.5 h; metabolised to caffeic acid and ferulic acid by colonic microbiota.
How They Measured It
Plasma rosmarinic acid and metabolites by LC-MS/MS
To review the clinical and pre-clinical evidence for rosmarinic acid across disease applications.
Study Type
Systematic review
Purpose
To review the clinical and pre-clinical evidence for rosmarinic acid across disease applications.
Dose
Varied
Participants
Multiple studies reviewed
Duration
Review
Results
Rosmarinic acid has consistent anti-inflammatory, antioxidant, and neuroprotective effects; clinical evidence is strongest for allergic rhinitis; expanding evidence for cognitive and metabolic benefits.
How They Measured It
Comprehensive literature synthesis
Frequently Asked Questions
Common questions about Rosmarinic Acid research
There are currently 10 peer-reviewed studies on Rosmarinic Acid (Rosmarinic acid (alpha-o-caffeoyl-3,4-dihydroxyphenyllactic acid)), involving 168 total participants. Research covers Anti-inflammatory, Allergy & asthma, Neuroprotection and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (5 human studies), and reported outcomes.
Rosmarinic Acid has been researched for: Anti-inflammatory, Allergy & asthma, Neuroprotection, Antioxidant protection. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 5 out of 10 studies are human trials. Human trials carry more weight in our evidence scoring system.
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