Luteolin (3',4',5,7-tetrahydroxyflavone) is a flavone found in celery, parsley, chamomile, artichoke, and green peppers. It is one of the most extensively studied dietary flavonoids, with 492+ publications in 2024-2026 alone and a rich preclinical evidence base spanning anti-infl
Clinical Summary
Luteolin (3',4',5,7-tetrahydroxyflavone) is a flavone found in celery, parsley, chamomile, artichoke, and green peppers. It is one of the most extensively studied dietary flavonoids, with 492+ publications in 2024-2026 alone and a rich preclinical evidence base spanning anti-inflammatory, neuroprotective, metabolic, and immunomodulatory pathways.
What it does well in the lab: Luteolin is a potent inhibitor of NF-κB, NLRP3 inflammasome, MAPK, and COX-2 pathways. It activates Nrf2 (antioxidant defense), AMPK (metabolic regulation), and stabilizes mast cells. It inhibits CD38 (NAD+ consumer), making it relevant to longevity research. Recent work shows ferroptosis regulation, PANoptosis inhibition, and epigenetic modulation (histone acetylation, DNA methylation).
The problem: Oral bioavailability is 5-10%. Extensive first-pass metabolism by UGT and SULT enzymes converts >90% to inactive conjugates. Achievable plasma concentrations (0.1-3 µmol/L) are often 10-100× below the IC50 values used in cell studies. This pharmacokinetic gap is the single biggest obstacle to clinical translation.
What has human evidence: Only the PEA+luteolin combination (ultra-micronized palmitoylethanolamide 700 mg + luteolin 70 mg) has meaningful RCT support — for post-COVID olfactory dysfunction (3 RCTs, N~300) and frontotemporal dementia (1 Phase 2 RCT, N=50). A 2024 critical evaluation (PMID 38861957) questioned the clinical meaningfulness of olfactory benefits. A 2026 cohort study (PMID 41493853) found luteolin supplementation associated with reduced kidney damage progression in diabetic patients — the first real human outcomes data for metabolic applications.
Who uses it: MCAS/mast cell activation syndrome patients (Theoharides NeuroProtek protocol), biohackers stacking for NAD+ preservation (CD38 inhibition), allergy sufferers, and longevity-focused individuals. The MCAS community is the largest user base.
Bottom line: A compound with exceptional preclinical credentials stuck in the clinical translation gap. The unpatentable nature of a natural flavonoid means no pharma company will fund the large RCTs needed. For now, only the PEA+luteolin combination for olfactory/neuroinflammatory conditions has defensible clinical evidence.
Reading this table: Stars = evidence volume. Type = what kind of evidence (see legend). BH = Bradford Hill causal strength (/9). Safety = FAERS/trial signals for THIS specific indication. One row = one decision.
Hard rule: Star rating cannot exceed the causal taxonomy ceiling for its Type. E.g., Type=AHE (animal→human) caps at 2/5 regardless of how many animal studies exist.
Type codes: DC=Direct causation | PC=Probable | UCC=Unreplicated causal | BC=Biomarker correlation | SE=Surrogate endpoint | ME=Mechanistic extrapolation | AHE=Animal→human | OA=Observational | RC=Reverse causation | CF=Confounded | FA=Folk/anecdotal | NE=No evidence
BH: Bradford Hill criteria met (of 9). 7-9=strong causal | 5-6=moderate | 3-4=weak | 1-2=speculative | 0=none
Safety flags:-- No signals | MON Monitor (known AEs, manageable) | WARN FAERS or trial safety signal — see Safety section | AVOID Contraindicated for this specific indication
Star rating legend:
Rating
Meaning
5/5
Multiple large RCTs + meta-analyses in humans
4/5
Several human RCTs OR extensive animal + limited human
3/5
Some human pilot data OR strong animal + mechanistic
2/5
Animal data only OR very limited human
1/5
No evidence, theoretical only, or debunked
Prescribing
Dosing Table
Population
Dose
Timing
Notes
Healthy adults (maintenance)
50-100 mg/day split BID
With fat-containing meals
Consistency > timing
Healthy adults (therapeutic)
100-300 mg/day split BID-TID
With fat-containing meals
Start low, titrate over 2 wk
PEA+lut combo (olfactory/neuro)
PEA 700mg + lut 70mg BID
With meals
Ultra-micronized form required
Allergy (seasonal)
100-200 mg/day
Start 2 wk before season
Adjunct, not monotherapy
IBD (active flare)
200-400 mg/day split BID
With meals; liposomal preferred
Absorption impaired in active IBD
Elderly (>65)
Start 50 mg/day → 200 mg max
With meals
Polypharmacy screening first
Renal impairment (GFR 30-59)
50% dose reduction
With meals
Conjugate accumulation risk
Hepatic impairment (Child-Pugh C)
Avoid
—
Impaired conjugation metabolism
Pregnancy / lactation
Avoid supplemental doses
—
Dietary sources (<5 mg/day) acceptable
Pediatric
Not recommended
—
No PK/safety data
Formulation Table
Form
Bioavailability
When to Use
Cost
Standard aglycone extract
5-10%
General maintenance, budget-conscious
$15-35/mo
Liposomal luteolin
15-25%
IBD, targeted therapy, GI-sensitive
$40-70/mo
Luteolin + Piperine (20mg)
10-15%
Enhanced absorption without liposomal cost
$20-40/mo
PEA+luteolin (ultra-micronized)
N/A (combo)
Olfactory dysfunction, FTD, neuroinflammation
$35-60/mo
Luteolin-7-O-glucoside
<5%
Not recommended (requires gut bacteria activation)
$15-25/mo
P-gp inhibition formulations
20-30% (projected)
Research phase — self-microemulsifying systems
Not available
Absorption essentials: Always take with 10-15g dietary fat (2-3× absorption improvement). Avoid high-fiber meals within 2 hours. Split dosing saturates conjugation enzymes more efficiently than single bolus. No cycling needed — no tolerance develops.
Topoisomerase II inhibition may interfere with doxorubicin/etoposide; antioxidant effects may protect cancer cells; BUT luteolin protects against dox-induced cardiotoxicity via PFKFB3 (PMID 41720006)
Avoid during active chemo unless oncologist approves
Rare (<0.1%): Elevated liver enzymes — isolated case reports, causality uncertain, monitor LFTs if >300 mg/day for >6 months; menstrual changes — theoretical estrogenic effects, anecdotal only
Serious (very rare): Bleeding events — primarily with anticoagulant co-use, no spontaneous reports from luteolin alone; DILI — extremely rare, more common with herbal combos
Photosensitivity — 1 FAERS report (report 21169941), non-serious, with pregabalin as primary suspect; not established as luteolin-caused
Animal toxicity note: 200 mg/kg caused liver/kidney toxicity in mice — equivalent to ~16g in 80kg human, far above any supplement dose (100-400 mg/day)
FAERS Signal Table (from BioMCP)
Reaction
FAERS Reports
Suspect Drug?
Seriousness
Linked Indication
Notes
Arthralgia
9
Luteolin as suspect
Mixed
MCAS treatment
Likely underlying condition, not drug effect
Drug ineffective
9
Luteolin as suspect
No
MCAS treatment
MCAS patients reporting treatment failure
Fatigue
7
Luteolin as suspect
Mixed
MCAS treatment
Confounded by underlying condition
Pain
7
Mixed
Mixed
Various
Non-specific, multi-drug reports
Anxiety
6
Mixed
Mixed
MCAS treatment
Underlying condition symptom
Depression
6
Mixed
Mixed
MCAS treatment
Underlying condition symptom
MCAS
6
Mixed
Serious
MCAS treatment
The condition being treated, not an AE
Rash
6
Mixed
No
Various
Non-specific
Photosensitivity
1
Concomitant (pregabalin suspect)
No
Pain
Only suspect-only report; pregabalin primary
Reading FAERS data: Of 29 total reports mentioning luteolin, only 1 listed luteolin as sole suspect drug (report 21169941: photosensitivity, rash, pain — non-serious). The remaining reports are from MCAS patients where luteolin was co-administered with other medications. The dominant FAERS signal is "drug ineffective" in MCAS patients — reflecting treatment failure for the underlying condition, not adverse effects from luteolin. Per FAERS supplement noise principles, these counts are heavily inflated by concomitant medication listings.
Met/Met carriers: may have enhanced response; Val/Val: standard dosing
CYP2C9 (rs1799853)
*2, *3 (poor metabolizer)
Reduced CYP2C9 → increased warfarin interaction risk with luteolin co-use
3/5 (established for warfarin)
CYP2C9 poor metabolizers on warfarin: extra caution with luteolin, more frequent INR checks
CYP3A4 (rs2740574)
*1B and others
Ultra-rapid metabolizers may have reduced drug interaction risk; poor metabolizers increased risk
2/5 (class effect)
Poor metabolizers: increased caution with CYP3A4 drug combinations
Community & Anecdotal Evidence
Disclaimer: This section captures real-world user reports from online communities. None of this constitutes clinical evidence. N-sizes are approximate. Selection bias, placebo effect, and recall bias are inherent. Presented for completeness, not as medical guidance.
Dominant Sentiment
Mixed across ~200-500 reports. Polarized between MCAS community (frequent users, mixed results) and nootropic/longevity community (theoretical interest, fewer actual users).
What Users Report
Reported Effect
Frequency
Typical Onset
Source Communities
Reduced brain fog
Moderate
1-4 weeks
Health Rising, r/MCAS, r/nootropics
Allergy symptom reduction
Moderate
1-2 weeks
r/supplements, MCAS forums
No noticeable effect
Common
After 4-8 weeks
Reddit, Health Rising, Longecity
Improved focus/mental clarity
Occasional
2-4 weeks
r/nootropics, biohacker blogs
Reduced MCAS flares
Mixed (some benefit, many report ineffective)
2-6 weeks
r/MCAS, Health Rising
GI upset (nausea, bloating)
Occasional
Immediate
r/supplements, iHerb reviews
Calming/anxiolytic effect
Occasional
1-2 weeks
r/nootropics, SelfHacked
Community Dosing vs Clinical
Source
Dose
Route
Notes
Clinical trials (PEA+lut)
PEA 700mg + lut 70mg BID
Oral (ultra-micronized)
The only validated protocol
MCAS community (NeuroProtek)
~100-200mg luteolin + quercetin + rutin
Oral (liposomal softgel)
Theoharides protocol; mixed reviews
Nootropic community
50-100mg + Forskolin 250mg
Oral (artichoke extract)
PDE4 inhibition stack; limited validation
Longevity/NAD+ community
50mg luteolin + NMN
Oral
CD38 inhibition for NAD+ preservation
Reddit average
100-200mg/day
Oral capsule
Standard supplementation
Biohacker high-dose
400mg/day
Oral
One report: 400mg daily CD38 inhibitors didn't significantly impact biological age metrics
Theoharides conflict of interest: Theoharis C. Theoharides is Scientific Director and shareholder of Algonot LLC, which manufactures NeuroProtek (the leading luteolin supplement). He holds US Patent No. 8,268,365 and 30+ patents/trademarks. His prolific publication record (hundreds of papers on mast cells and luteolin) creates a single-researcher dependency where much of the luteolin clinical narrative flows through one person with direct financial interest.
MLM involvement: None detected. Luteolin is not MLM-distributed.
Influencer concentration: Moderate — Dr. Theoharides is the dominant voice. Biohacker/longevity channels mention it occasionally but no single influencer drives hype.
Astroturfing signals: No clear patterns detected. Community sentiment is genuinely mixed, which argues against coordinated promotion.
"All that glitters" editorial: Theoharides himself published an editorial titled "Luteolin supplements: All that glitters is not gold" (2020) acknowledging quality and bioavailability problems — a point of intellectual honesty despite commercial interest.
Folk vs Clinical Reality Check
Community experience largely aligns with clinical data in one key area: the PEA+luteolin combination for brain fog and olfactory issues generates the most positive reports, consistent with RCT evidence. The biggest divergence is in MCAS: the community treats luteolin as a first-line mast cell stabilizer based on in vitro data, but FAERS data shows "drug ineffective" as the top reaction — many MCAS patients find it doesn't help. The nootropic/PDE4 inhibition use case (artichoke extract + forskolin) has theoretical mechanistic support but zero clinical validation. The CD38/NAD+ use case is mechanistically plausible but one biohacker's n=1 experiment with 400mg daily showed no biological age impact, consistent with the bioavailability problem limiting real-world efficacy.
FDA: Not approved as drug. Dietary supplement status. DrugBank ID: DB15584.
EMA: Not approved as drug. No monograph.
Regulatory context: Natural flavonoid — unpatentable, no commercial incentive for pharma to pursue drug approval. GRAS as food constituent. The clinical translation gap is primarily economic, not safety-driven.
No human RCT for luteolin monotherapy; bioavailability limits in vivo translation
Allergy / mast cell stabilization
ME
4/9
MON
FAERS: "drug ineffective" is top signal in MCAS users; in vitro potency ≠ in vivo efficacy
Metabolic / insulin sensitivity
AHE
4/9
--
Strong animal data but zero human RCTs; one observational cohort (PMID 41493853)
IBD / ulcerative colitis
AHE
4/9
--
Preclinical meta-analysis (PMID 40808687) but zero human trials
Neuroprotection / cognitive decline
AHE
3/9
--
CNS penetration unvalidated; FTD data is PEA+lut combo, not monotherapy
Cancer treatment
ME
2/9
WARN
IC50 concentrations 10-100× above achievable plasma levels; may interfere with chemo
Depression / anxiety
AHE
2/9
--
Animal behavioral data only; one flavone meta-analysis (PMID 39996320)
Hype Check (Mode 1: Fallacy Radar)
Hasty generalization (HIGH): Animal/in-vitro findings extrapolated to human supplementation throughout. "30-50% reduced neuronal death" in rodents presented alongside human dosing recommendations without acknowledging the species gap.
Composition fallacy (MEDIUM): PEA+luteolin combination shows clinical benefit, but luteolin alone gets credited. The file previously rated "luteolin alone (extrapolated)" at 3/5 based on combo evidence.
Appeal to mechanism (MEDIUM): "NF-κB inhibition, AMPK activation, Nrf2 activation" — mechanistic plausibility treated as evidence of clinical effect. Thousands of compounds inhibit NF-κB in vitro; very few produce human benefit.
Cherry-picking (MEDIUM): Cancer section emphasizes extensive in vitro anti-cancer effects while the pharmacokinetic impossibility (IC50 10-100× above achievable plasma) makes oral supplementation for cancer essentially moot.
Evidence Gaps
Zero human PK study establishing tissue-level concentrations at standard supplement doses
Zero head-to-head formulation comparison in humans (aglycone vs liposomal)
Zero IBD human clinical trial despite preclinical meta-analysis demanding it
Zero metabolic syndrome RCT despite 400+ animal studies
Zero pharmacogenomic stratification study (UGT1A1 effects on bioavailability unknown in humans)
Zero long-term safety study >12 months
No data on whether oral luteolin meaningfully crosses the blood-brain barrier
Bias Flags (Mode 4: First Principles)
Unexamined assumption #1: "Oral supplementation at 100-300mg achieves therapeutic tissue concentrations" — with 5-10% bioavailability and >90% conjugation, actual free luteolin at target tissues may be negligible. This is the load-bearing assumption for the entire supplement category.
Unexamined assumption #2: "Anti-inflammatory mechanisms translate to clinical benefit" — most NF-κB inhibitors fail clinically. Being a potent in vitro inhibitor is necessary but nowhere near sufficient.
Unexamined assumption #3: "Luteolin works as monotherapy" — ALL clinical evidence is for combination therapy (PEA+luteolin). Standalone supplement recommendations are extrapolation.
Manipulation Flags (Mode 2: Manipulation Shield)
Industry marketing: Moderate. NeuroProtek/Algonot LLC markets luteolin supplements for MCAS, autism, and brain fog. Claims are qualified but the single-researcher pipeline (Theoharides → Algonot → NeuroProtek) creates a closed loop where the researcher, manufacturer, and brand are the same entity.
Influencer economics: Low-moderate. Dr. Theoharides dominates the luteolin narrative through 30+ patents and hundreds of publications. No major social media influencer drives hype.
Counter-narrative manipulation: No significant anti-luteolin actors detected. The compound is too small-market for pharma suppression.
Cui bono summary:Who wins if you take it: Supplement manufacturers (Algonot/NeuroProtek, Life Extension, Swanson), Theoharides' research group. Who wins if you don't: Nobody — there's no competing product with incentive to suppress luteolin. The honest assessment is that nobody has strong financial motive to either inflate or suppress this compound, except the single researcher-manufacturer entity.
Red team highlight: The most concerning angle is evidence quality — the entire clinical narrative rests on PEA+luteolin combination therapy for olfactory dysfunction, conducted by research groups connected to the supplement manufacturer. Independent replication from groups without commercial interest is the single most important missing piece. The 2024 German critical evaluation (PMID 38861957) from an independent group questioning clinical meaningfulness is the most important counterpoint.
Decision Support (Mode 3: Clarity Compass)
Health utility score: 5/10 — broad preclinical anti-inflammatory profile with universal theoretical relevance, but weak bioavailability (5-10%), no validated human monotherapy dose, and sparse independent clinical data limit real-world utility.
Opportunity cost: $15-45/month for a compound with 5-10% bioavailability and no validated human dose. Could be spent on better-validated options (Omega-3, Curcumin with human RCTs, Quercetin with some clinical data).
Verdict:WATCH LIST
Conditions (revisit when): (a) A human dose-response trial is published for any indication as monotherapy, (b) bioavailability solutions (P-gp inhibition SMEDDS, PMID 41570979) reach commercial market, (c) FTD Phase 2 results are independently replicated, (d) the NCT06718452 tinnitus trial or NCT06777680 stroke trial report results
Exception: PEA+luteolin combination for post-viral olfactory dysfunction — this specific use is CONDITIONAL (only if dealing with persistent anosmia/parosmia >6 months post-infection)
Bottom Line
Luteolin has one of the richest preclinical portfolios of any dietary flavonoid — 492+ publications in 2024-2026, mechanisms spanning NF-κB to ferroptosis to epigenetics, and a safety profile that appears favorable. But the compound is trapped in the supplement industry's most common failure mode: extraordinary lab promise, inadequate clinical proof. The 5-10% bioavailability means most of what you swallow never reaches its targets as free compound. The only validated clinical application is the PEA+luteolin combination for olfactory dysfunction and neuroinflammation, and even that is being questioned by independent groups. The unpatentable nature of a natural flavonoid means the large RCTs needed to move the needle will likely never be commercially funded. For biohackers willing to accept that calculated uncertainty: the safety profile supports self-experimentation at 100-200 mg/day, monitoring is minimal, and the downside risk is primarily wasted money. For evidence-based decision-makers: WATCH LIST until human monotherapy data emerges.
PEA+luteolin: Guna (ultra-micronized, used in clinical trials), Epitech Group
Quality markers: >98% luteolin by HPLC; heavy metals <10 ppm; CoA available on request
Red flags: Proprietary blends, "100% absorption" claims, no CoA, <$10/month pricing
Storage & Handling
Standard capsules: room temp (15-25°C), opaque container, away from humidity. Shelf life 2-3 years unopened.
Liposomal: refrigerate after opening, 6-12 month shelf life opened. Phospholipids oxidize.
Luteolin degrades with UV exposure — always store in amber/opaque container.
Palatability & Compliance
Powder is slightly bitter — capsules preferred for most users
Can mix into smoothies, nut butter, or full-fat yogurt if using powder
Avoid mixing with hot liquids >60°C (degrades luteolin)
Split dosing improves compliance vs 3x daily
Exercise & Circadian Timing
No strong circadian effects identified; consistency > timing
Pre-exercise (1-2h before): theoretical anti-inflammatory benefit, no human exercise data
One animal study suggests luteolin-7-glucoside enhances sleep via GABAergic modulation (PMID 41276885) — evening dosing may have marginal benefit, but unvalidated
NCT07280520 (athletic performance trial, enrolling) will be first human exercise data
Cost
Standard extract: $0.50-1.50/day ($15-45/month)
Liposomal: $1.50-2.50/day ($45-75/month)
PEA+luteolin: $1.50-2.00/day ($45-60/month)
Dietary sources (celery, parsley, artichoke): essentially free but provide only 1-5mg/day
What We Don't Know
Whether oral luteolin supplements achieve therapeutically relevant tissue concentrations in any organ
The optimal human dose for any indication (all dosing is extrapolated from animals)
Whether luteolin crosses the blood-brain barrier in meaningful amounts after oral dosing
Long-term safety beyond 12 months of continuous supplementation
Whether luteolin-7-glucoside (plant form) is effectively converted to active aglycone by human gut bacteria
The real contribution of luteolin vs PEA in combination therapy
Whether UGT1A1 polymorphisms (Gilbert syndrome) meaningfully alter supplement bioavailability
Whether the CD38 inhibition observed in vitro translates to NAD+ preservation at supplement doses in humans
Whether newer delivery systems (P-gp inhibition SMEDDS, intranasal nanocomposites) will solve the bioavailability problem
Whether the hormetic dose-response (PMID 34403687) means lower doses are actually more effective than higher doses
Whether the new eye health data (photoreceptor protection, vitreoretinopathy, glaucoma) translates to oral supplementation benefits
References
Systematic Reviews & Meta-Analyses
Capra AP et al. (2023). PEA+luteolin for post-COVID olfactory dysfunction meta-analysis. Biomedicines. PMID: 37626685
Shi Y et al. (2026). Anti-neuroinflammatory supplement + OT for post-COVID olfactory disorders SR+MA. Eur Arch Otorhinolaryngol. PMID: 41559316
Feng Y et al. (2025). Preclinical evidence for luteolin in UC meta-analysis. Front Pharmacol. PMID: 40808687
Wang Q et al. (2025). Antidepressant activity of flavones meta-analysis. Pharm Biol. PMID: 39996320
Bischoff S et al. (2024). Treatment of COVID-19 olfactory dysfunction SR. Curr Allergy Asthma Rep. PMID: 39477832
Guo H et al. (2026). Global research landscape luteolin bibliometric. Front Nutr. PMID: 41684783
Landmark RCTs & Clinical Trials
Di Stadio A et al. (2023). PEA+luteolin RCT, COVID olfactory, N=202. Eur Arch Otorhinolaryngol. PMID: 37380908
Cantone E et al. (2024). PEA+luteolin vs ALA, COVID parosmia, N=85. Eur Arch Otorhinolaryngol. PMID: 38492007