Luteolin
A flavone that inhibits mast cell activation. It gets attention in long-COVID and mast cell activation syndrome discussions, mostly on mechanism rather than trial data.
Luteolin quick facts
| Suggested dose | 100–300 mg daily, usually with quercetin and with a fat source. |
| How often | daily |
| Who it's for | Discussed for mast cell and neuroinflammatory symptoms. Evidence is mechanistic. |
Mechanistically well-founded and clinically under-evidenced, with human trials small and mostly in combination products. Frequently paired with PEA on the shared glial mechanism. It has aromatase-inhibiting activity, which is worth knowing for anyone managing estradiol. Poorly absorbed alone; formulation matters more than dose.
How Luteolin actually works
A flavone that inhibits mast-cell activation and microglial inflammatory signaling, crosses the blood-brain barrier, and inhibits several inflammatory kinases. It is central to the neuroinflammation model of brain fog — the argument that persistent fog with intact attention is glial rather than neurotransmitter in origin.
Where to get Luteolin
Find Luteolin on iHerb →The evidence for Luteolin
Graded by what exists behind each claim.
✅ Clinically validated
- Small open-label studies in children with autism and in adults with brain fog report symptom improvement — uncontrolled, so hard to weigh.
- No adequately powered placebo-controlled trial exists in any indication.
📊 Correlative data
- Dietary flavone intake is associated with lower inflammatory markers in cohort studies.
🧪 Theoretical / extrapolated benefits
- Inhibits mast cell degranulation and microglial activation in preclinical models, which is the basis of the neuroinflammation hypothesis it is sold on.
How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →
What Luteolin actually does
Luteolin is 3',4',5,7-tetrahydroxyflavone. It differs from apigenin by a single hydroxyl on the B ring, and that one group makes a catechol — which is why luteolin chelates transition metals, quenches radicals more effectively, and is conjugated and methylated differently in the gut and liver.
The cellular action is a named kinase pathway, not a vague anti-inflammatory claim. Luteolin reduces interleukin-6 production in microglia by inhibiting the phosphorylation of c-Jun N-terminal kinase and thereby the activation of the transcription factor AP-1 Jang 2008. That is a specific route from a flavone to a cytokine, in the specific cell type the neuroinflammation hypothesis is about.
The mast cell action is the second half and the reason this molecule has a following. Luteolin inhibits mast cell activation, and its effect on mast cells together with T cells is the basis of the multiple sclerosis proposal Theoharides 2007. Mast cells sit perivascularly in the brain and degranulate onto microglia, which is the mechanistic bridge under the “brain fog” hypothesis Theoharides 2015 and under the long-COVID proposal built on top of it Theoharides 2021.
The mechanism has to survive its own absorption chemistry, and this is where it gets difficult. In rat everted small intestine, luteolin is converted to glucuronides while crossing the mucosa; luteolin 7-O-beta-glucoside is absorbed only after hydrolysis to the aglycone; and the principal species circulating in blood is a monoglucuronide of the unchanged aglycone, alongside free luteolin and methylated conjugates. Absorption was faster from propylene glycol than from 0.5% carboxymethyl cellulose, with plasma peaking at 15 and 30 minutes respectively Shimoi 1998. Almost everything in circulation is conjugated, and a glucuronide is not the molecule that was applied to the microglia in the dish.
Cell, rodent, human — and where it stops
Cell: IL-6 suppression in microglia through JNK and AP-1 Jang 2008; mast cell inhibition Theoharides 2007.
Rodent, and this is the strongest preclinical link between an oral dose and a brain readout. Dietary luteolin reduced proinflammatory microglia in the brains of senescent mice Burton 2016 — oral exposure, aged animals, brain tissue as the endpoint. That is the design the human question needs and it was run in mice.
Human, and there is exactly one trial of any length. Fifty children aged 4 to 10 with autism spectrum disorder, 42 boys and 8 girls, enrolled in a 26-week prospective open-label trial of a formulation containing luteolin 100 mg from chamomile, quercetin 70 mg and the quercetin glycoside rutin 30 mg per capsule, formulated in olive kernel oil to increase absorption, dosed at one capsule per 10 kg body weight per day with food. Forty completed. Vineland Adaptive Behavior Scales age-equivalent scores improved by 8.43 months in communication, 7.17 months in daily living skills and 8 months in the social domain, p < 0.005; Aberrant Behavior Checklist subscale scores fell by 26.6% to 34.8%; and 27 of the 50 participants had transient increased irritability lasting 1 to 8 weeks Taliou 2013.
The obstacle here is unusually clean, so it is worth spelling out. That trial has no control group. Twenty-six weeks of ordinary development in a 4-to-10-year-old produces gains in age-equivalent scores with no capsule at all, which is precisely why the outcome was expressed in months of age-equivalence and precisely why an open-label design cannot interpret the number. The formulation contained three flavonoids, so no result in it belongs to luteolin. The population was autistic children and the reader is an adult with brain fog. And the long-COVID literature that drives current demand is a mechanistic proposal rather than a trial Theoharides 2021. There is no adequately powered placebo-controlled trial of luteolin in any indication in adults. That single sentence is the honest summary of this molecule's clinical evidence.
Luteolin — which form, and does it matter
Aglycone versus glycoside. Luteolin 7-O-glucoside must be hydrolyzed before the aglycone can be absorbed Shimoi 1998, so a milligram of glycoside and a milligram of aglycone are not the same dose and the difference depends on your gut flora.
The vehicle is part of the intervention, not packaging. Absorption was faster from propylene glycol than from a cellulose suspension Shimoi 1998, and the human trial deliberately formulated its flavonoids in olive kernel oil to increase oral absorption Taliou 2013. A dry luteolin capsule swallowed on an empty stomach is the least absorbable version of this molecule. The card's advice to take it with a fat source is right for a reason it does not give: the studied product was a lipid formulation.
Source decides the impurity profile. The trial's luteolin was chamomile-derived at greater than 95% purity Taliou 2013; commercial luteolin is also extracted from peanut hull, Sophora and perilla, with different accompanying flavonoids and different residual solvent questions.
Quercetin travels with it almost everywhere, including in the trial. The studied capsule was luteolin plus quercetin plus rutin Taliou 2013, and most retail products pair luteolin with quercetin as well. A “luteolin result,” clinically and personally, is almost always a luteolin-plus-quercetin result.
What would have to be true, and how you would know it was not
There is no blood test for brain fog, and this is the page where that has to be said rather than fudged. So: instruments, twice, at a fixed interval, plus the one mechanistic marker that exists.
1. The symptom read. The Fatigue Severity Scale and a cognitive-failures questionnaire at day 0 and day 56, plus a 10-minute psychomotor vigilance task at both ends at the same hour, on 100–300 mg/day taken with food. Predict no change beyond regression to the mean, because there has never been a controlled trial of this molecule in adults Taliou 2013.
2. The one marker worth drawing, and it is the mechanistic one. High-sensitivity CRP at day 0 and day 56, with interleukin-6 if you can get it. Predict no measurable fall. The IL-6 suppression was demonstrated in microglia in culture Jang 2008, the brain-tissue effect was in mice Burton 2016, and no human has ever been shown to change a systemic cytokine on a supplement dose of luteolin.
3. The prediction that cuts against the product. Predict that if you feel better it happens in the first fortnight and fades by week eight. That is the shape of an expectancy response in an uncontrolled setting, and an uncontrolled setting is the only one this molecule has ever been tested in Taliou 2013. It is also the shape you should expect from a fluctuating symptom that people start supplements during the worst of.
4. TSH at baseline and at 12 weeks if you take it daily, because flavones of this class have been reported to affect thyroid hormone economy and nobody has characterized luteolin at supplement doses. This is a monitoring recommendation from chemistry, labeled as such.
What will fool you: quercetin, which is in the capsule with it Taliou 2013, and the natural course of brain fog, which waxes and wanes on its own over exactly the timescale people run these experiments on.
What nobody has tested yet
Nobody has run a placebo-controlled trial of luteolin in any indication in adults. That sentence is the whole page. The card's own admission that this one is honestly mechanism-only in humans is correct, and it is rare enough on a supplement shelf to be worth crediting.
Nobody has measured plasma luteolin and its glucuronide in a human after a labeled supplement dose. The absorption and conjugation chemistry is rat work Shimoi 1998. Ten adults, a 200 mg capsule with food, eight draws over 24 hours, aglycone and conjugate quantified separately.
Nobody has shown a luteolin species reaches the human brain. The mouse study demonstrated a brain-tissue microglial effect from dietary exposure Burton 2016; there is no human cerebrospinal fluid measurement and no imaging ligand.
Nobody has separated luteolin from quercetin. The single human dataset used both plus rutin Taliou 2013, so it can attribute nothing to either. A two-arm trial of luteolin alone against luteolin plus quercetin would cost little and would tell every buyer on this shelf which molecule they are paying for.
And nobody has tested the mast cell hypothesis where it is loudest. A randomized placebo-controlled trial in mast cell activation syndrome or in post-viral brain fog, with serum tryptase, hs-CRP and a validated symptom scale, has never been published Theoharides 2021 Theoharides 2015. The hypothesis is ten years old and the trial is still missing.
Luteolin — its own safety story, not its category's
The one adverse effect anybody has actually counted. In the 26-week trial, 27 of 50 participants developed transient increased irritability lasting between 1 and 8 weeks Taliou 2013. That is more than half of the people who took it, it resolved, and it is worth knowing before you start rather than after — particularly if you are taking it for a symptom that irritability makes worse.
CYP inhibition in vitro gives a theoretical interaction with drugs cleared by those enzymes. “Clinical significance not established” here means nobody has looked, which is a different statement from somebody having looked and found nothing. If you take a narrow-therapeutic-index drug, that distinction matters.
Thyroid. Flavones of this class can affect thyroid hormone economy and luteolin has not been characterized at supplement doses. Monitor TSH if you have thyroid disease.
The specific risk of this product is substitution, not toxicity, and it is a serious one. Luteolin is bought by people with long COVID, ME/CFS or mast cell symptoms who are genuinely ill and often poorly served, on the strength of a mechanistic hypothesis Theoharides 2021 and one uncontrolled trial in children Taliou 2013. Spending six months and several hundred pounds on a mechanism-only supplement has a real cost when the differential for brain fog includes iron deficiency, hypothyroidism, obstructive sleep apnea, B12 deficiency, celiac disease and depression — all of which are testable, several of which are treatable in weeks, and none of which a flavone addresses.
Who should not take it: anyone on a narrow-therapeutic-index drug cleared by CYP enzymes without checking; anyone with thyroid disease not being monitored; anyone pregnant or breastfeeding, where there is no data at all; and anyone who has not yet had the boring blood tests, because those are the ones that find the answer.
Sources read for this page
- Jang S, Kelley KW, Johnson RW. Luteolin reduces IL-6 production in microglia by inhibiting JNK phosphorylation and activation of AP-1. Proceedings of the National Academy of Sciences 2008 · PMID 18490655
- Shimoi K, Okada H, et al. Intestinal absorption of luteolin and luteolin 7-O-beta-glucoside in rats and humans. FEBS Letters 1998 · PMID 9827549
- Burton MD, Rytych JL, et al. Dietary Luteolin Reduces Proinflammatory Microglia in the Brain of Senescent Mice. Rejuvenation Research 2016 · PMID 26918466
- Taliou A, Zintzaras E, et al. An open-label pilot study of a formulation containing the anti-inflammatory flavonoid luteolin and its effects on behavior in children with autism spectrum disorders. Clinical Therapeutics 2013 · PMID 23688534
- Theoharides TC, et al. Mast cells, T cells, and inhibition by luteolin: implications for the pathogenesis and treatment of multiple sclerosis. Advances in Experimental Medicine and Biology 2007 · PMID 17713031
- Theoharides TC, Stewart JM, et al. Brain 'fog,' inflammation and obesity: key aspects of neuropsychiatric disorders improved by luteolin. Frontiers in Neuroscience 2015 · PMID 26190965
- Theoharides TC, Cholevas C, et al. Long-COVID syndrome-associated brain fog and chemofog: Luteolin to the rescue. BioFactors 2021 · PMID 33847020
How you would know if it worked
There is no blood test for this one. That is not a criticism — it is a fact about the effect, and it changes how you should judge it.
- What to watch: A specific symptom with a count, not a syndrome. Flushing episodes per week. Times per day the fog is bad enough to stop what you are doing. Hives, or a heart rate that spikes on standing. The mast cell hypothesis it is sold on predicts particular symptoms, and only a count will separate those from the week they happened in.
- How long before it means anything: Four to eight weeks, taken with fat, since absorption without one is poor. There is no trial to point at for a window, which is itself the most useful fact about this compound.
- What will fool you: No adequately powered placebo-controlled trial exists in any indication, so nothing here is settled and a coherent mechanism is doing all the work. It is also almost always taken with quercetin, which means an effect cannot be assigned to either. Mast cell and post-viral symptoms swing hard on their own, so a good month is well inside what they do untreated.
Run it one variable at a time. Starting three things in one week means a result you cannot attribute, which is the same as no result.
Luteolin — safety & side effects
- Well tolerated; GI upset at higher doses.
- Inhibits several CYP enzymes in vitro, so theoretically it can raise levels of medications cleared that way. The clinical significance is not established.
- May lower thyroid hormone. Long-term safety has not been characterized — the trials run weeks to months, not years. That is a real limit on what anyone can tell you about daily use for a decade.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this against it with a pharmacist or doctor — pharmacists are underused and free.
- When to take it, and what to take it with
- Which form actually absorbs
- Who it's worth it for
- Coach Cam's stacks and notes
- Fasted or with food, and when in the day
- Morning or night, and why that window
- Around training, or deliberately away from it
- What it must not share a window with
Everything above is free and stays free. Skool is where it becomes a plan — Luteolin in an order, with the rest of what you're running.
Unlock in Skool — $10/mo →Bloodwork to run alongside Luteolin
Baseline first, then again at 8–12 weeks.
| Marker | What it’s watching for |
|---|---|
| TSH (Thyroid-Stimulating Hormone) | Thyroid disease imitates every cognitive complaint there is |
| Vitamin B12 | Deficiency causes fog long before it causes anemia |
| Methylmalonic Acid (MMA) | Catches the deficiency a normal B12 hides |
| Ferritin | Low iron flattens cognition at levels most labs call fine |
| Vitamin D (25-Hydroxy) | Commonly low, cheap to correct, associated with mood |
The Brain Fog & Cognition panel covers these in one order — 12 markers, $233.06 with the discount applied.
Check results you already have → · All 103 markers A–Z
Luteolin — frequently asked questions
What is Luteolin?
A flavone that inhibits mast cell activation. It gets attention in long-COVID and mast cell activation syndrome discussions, mostly on mechanism rather than trial data.
What is the suggested dose of Luteolin?
100–300 mg daily, usually with quercetin and with a fat source. This is a general reference for education only — statements have not been evaluated by the FDA and this is not medical advice.
Where can I find Luteolin dosing and the full breakdown?
The suggested dose and the full evidence — clinical, correlative and theoretical — are on this page. What's inside Skool is when to take it, which form actually absorbs, the brand worth buying and Coach Cam's stacks.
Where can I buy Luteolin?
Coach Cam sources Luteolin from vetted, top-rated brands on iHerb — use the buy link on this page.
Luteolin inside a finished plan
One arm of 1 Protocol Blueprint, free to read in full.
What Luteolin is used for
Luteolin appears under 4 goals in the goal router.
Related Cognitive & Mood supplements
Where this goes next
Luteolin is the neuroinflammation arm of this plan. The page above is the free breakdown of one compound; the plan it belongs to — the dosing, the order to correct things in, the week-by-week schedule and what to retest — is a lesson inside Skool.