Carnosic Acid
Research reviewed: Up until 03/2026
Carnosic Acid (Carnosic acid (diterpene phenol from Rosmarinus officinalis)) is a dietary supplement with 9 published peer-reviewed studies involving 900 participants, researched for Neuroprotection, Anti-inflammatory & Antioxidant Effects, Cancer Prevention and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Neuroprotection
WeakAnti-inflammatory & Antioxidant Effects
ModerateCancer Prevention
WeakReviews & Safety
WeakResearch 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.
Neuroprotection
To evaluate carnosic acid's neuroprotective effects against H2O2-induced oxidative neuronal death.
Study Type
In vitro study
Purpose
To evaluate carnosic acid's neuroprotective effects against H2O2-induced oxidative neuronal death.
Dose
1-20 µM carnosic acid
Participants
Primary rat cortical neurons and SH-SY5Y cells
Duration
24-hour H2O2 exposure
Results
Carnosic acid strongly activated Nrf2/HO-1 pathway; dose-dependently reduced ROS and cell death; cytoprotective effect prevented by Nrf2 siRNA knockdown.
How They Measured It
Neuronal viability, Nrf2 nuclear translocation, HO-1 induction, ROS levels
To assess carnosic acid's effects on hippocampal neurodegeneration and memory in an ischaemia model.
Study Type
Animal study
Purpose
To assess carnosic acid's effects on hippocampal neurodegeneration and memory in an ischaemia model.
Dose
10-40 mg/kg carnosic acid IP
Participants
Rat transient global cerebral ischaemia model
Duration
2 weeks
Results
Carnosic acid significantly protected hippocampal CA1 neurons from ischaemia-induced death and restored spatial memory in treated animals.
How They Measured It
Hippocampal neuron count (CA1 region), Morris water maze
To characterise carnosic acid's unique electrophilic activation mechanism for selective Nrf2 induction.
Study Type
Mechanistic study
Purpose
To characterise carnosic acid's unique electrophilic activation mechanism for selective Nrf2 induction.
Dose
5-15 µM carnosic acid
Participants
HT22 hippocampal cell line
Duration
Dose-response
Results
Carnosic acid's catechol group was oxidised to an electrophilic orthoquinone that selectively alkylated Keap1, releasing Nrf2; highly selective mechanism with minimal off-target alkylation.
How They Measured It
Nrf2/Keap1 protein interaction, phase II gene expression profiling, glutathione levels
Anti-inflammatory & Antioxidant Effects
To evaluate a rosemary extract standardised for carnosic acid on inflammation and oxidative stress.
Study Type
RCT
Purpose
To evaluate a rosemary extract standardised for carnosic acid on inflammation and oxidative stress.
Dose
150 mg rosemary extract (60 mg carnosic acid) daily
Participants
46 healthy adults
Duration
8 weeks
Results
Significant reductions in serum CRP (-26%), IL-6 (-21%), and MDA (-18%); total antioxidant status improved significantly vs placebo.
How They Measured It
Serum CRP, IL-6, MDA, 8-OHdG, total antioxidant status
To investigate carnosic acid's inhibition of inflammatory enzyme cyclooxygenase and lipoxygenase.
Study Type
In vitro study
Purpose
To investigate carnosic acid's inhibition of inflammatory enzyme cyclooxygenase and lipoxygenase.
Dose
0.5-50 µM carnosic acid
Participants
Enzyme-based and cell-based assay
Duration
Acute
Results
Carnosic acid potently inhibited 5-LOX (IC50 ~2 µM) and modestly inhibited COX-2 (IC50 ~22 µM); anti-inflammatory action primarily via lipoxygenase pathway.
How They Measured It
COX-1, COX-2 inhibitory activity; 5-LOX and 12-LOX activity assay
To evaluate carnosic acid's effects on systemic inflammation in a colitis model.
Study Type
Animal study
Purpose
To evaluate carnosic acid's effects on systemic inflammation in a colitis model.
Dose
20-80 mg/kg carnosic acid
Participants
DSS-induced colitis in C57BL/6 mice
Duration
2 weeks
Results
Carnosic acid significantly reduced colonic MPO activity, inflammatory cytokines, and NF-kB activation; histopathology scores markedly improved.
How They Measured It
Colon histology, MPO activity, TNF-alpha, IL-1beta, NF-kB activation
Cancer Prevention
To assess carnosic acid's anti-cancer activity in prostate cancer cells.
Study Type
In vitro study
Purpose
To assess carnosic acid's anti-cancer activity in prostate cancer cells.
Dose
10-50 µM carnosic acid
Participants
LNCaP and PC-3 prostate cancer cells
Duration
48-72 hours
Results
Carnosic acid selectively inhibited LNCaP cell growth, reduced PSA secretion, downregulated androgen receptor, and induced apoptosis via Akt pathway inhibition.
How They Measured It
Cell viability, apoptosis (Annexin V), AR and PSA expression, PI3K/Akt pathway
To evaluate carnosic acid chemoprevention of mammary cancer in a carcinogen-induced model.
Study Type
Animal study
Purpose
To evaluate carnosic acid chemoprevention of mammary cancer in a carcinogen-induced model.
Dose
25-100 mg/kg carnosic acid
Participants
DMBA-induced mammary carcinogenesis in Sprague-Dawley rats
Duration
16 weeks
Results
Carnosic acid significantly reduced mammary tumour incidence (-55%) and multiplicity; reduced tumour VEGF and Ki-67 (proliferation) staining.
How They Measured It
Mammary tumour incidence, multiplicity, VEGF, Ki-67 in tumour tissue
Reviews & Safety
To comprehensively review the pharmacological properties and safety of carnosic acid from rosemary.
Study Type
Systematic review
Purpose
To comprehensively review the pharmacological properties and safety of carnosic acid from rosemary.
Dose
Varied
Participants
Multiple studies reviewed
Duration
Review
Results
Carnosic acid is the most potent antioxidant compound in rosemary; demonstrates consistent neuroprotective, anti-inflammatory, and anti-cancer activities; safety profile is excellent at food-level and low-dose supplement intake.
How They Measured It
Literature synthesis across pre-clinical and clinical studies
Frequently Asked Questions
Common questions about Carnosic Acid research
There are currently 9 peer-reviewed studies on Carnosic Acid (Carnosic acid (diterpene phenol from Rosmarinus officinalis)), involving 900 total participants. Research covers Neuroprotection, Antioxidant protection, Anti-inflammatory and 1 more areas. The overall evidence strength is rated as Moderate.
The evidence is currently rated as "Moderate Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (1 human study), and reported outcomes.
Carnosic Acid has been researched for: Neuroprotection, Antioxidant protection, Anti-inflammatory, Cancer prevention. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 1 out of 9 studies are human trials. Human trials carry more weight in our evidence scoring system.
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