What is ergothioneine?

A naturally occurring antioxidant compound, notable partly because the body has a dedicated transporter for it — which is the genuinely interesting part of its biology.

Why do formulators like ergothioneine?

Stability. It holds up well in formulation, which matters more in a finished product than a raw ingredient's headline antioxidant number.

What is not yet established about it?

The article states its own honest limit: what is known about ergothioneine and skin does not yet amount to a demonstrated hair outcome, and it is not presented as one.

Ergothioneine: The Antioxidant You Have Not Heard Of

2026年8月17日

By Dr. Susan Lin, MD | MD HAIR | La Cañada Ventures, Inc.
Published on mdhair.com — Verbascoside & Lilac Science Series

You have reached the point in your research where you are reading ingredient lists. Not the front of the box — the actual list on the back, in six-point type, in an order you have half-learned to interpret. You have taught yourself what niacinamide is. You know roughly what a peptide is supposed to do. You have opinions about panthenol.

And then there is a word in the middle of the list that you have never seen anywhere else, that does not appear in any of the articles you have read, and that has no marketing story attached to it at all: ergothioneine.

It looks like something a chemist put in. It is, in fact, something a mushroom put in.

I want to spend this article on it, because it is the most genuinely interesting molecule I formulate with — and because the honest version of its story is more compelling than the version a marketing department would write. It is a compound your body cannot make, obtains only from your diet, and then goes to unusual and specific trouble to hold on to. That is a real biological fact with real implications, and it does not need to be exaggerated.

I am Dr. Susan F. Lin, M.D. — physician formulator behind the MD® line at La Cañada Ventures, Inc., trained at Boston University School of Medicine, board-certified in Obstetrics & Gynecology and in Anti-Aging Medicine (A4M), formulating for hair and skin since 2008.

I will also tell you at the outset where this article stops, because that boundary is the part most ingredient articles omit. Ergothioneine is an antioxidant in a cosmetic. No antioxidant has been shown to reverse pattern hair loss, and I am not going to imply that this one does. What follows is why it is nonetheless worth understanding, and worth having in a formula.

What It Is, and Where It Comes From

Ergothioneine is a naturally occurring thiourea derivative of the amino acid histidine — in plain terms, a small sulfur-containing molecule built on a histidine backbone. It was first isolated in 1909 from the ergot fungus, which is where the name comes from.

Here is the first genuinely unusual fact about it: almost nothing that isn't a fungus or a mycobacterium can make it. Biosynthesis is essentially restricted to certain fungi and bacteria. Plants do not synthesise it either — they acquire it from the soil, via fungal and microbial sources in the root environment.

Humans cannot synthesise it at all. Every molecule of ergothioneine in your body arrived through your diet.

The dietary sources are correspondingly specific. Mushrooms are the standout — by a wide margin, and with substantial variation between species; oyster, shiitake, maitake and king oyster mushrooms are reported at considerably higher levels than the common white button mushroom, though the button mushroom still contributes meaningfully because of how much of it people eat (Kalaras et al., 2017). Beyond fungi, it appears in smaller amounts in foods grown in ergothioneine-containing soils and in animal tissues from animals that ate them — oats, beans, liver and kidney among them (Ey, Schömig & Taubert, 2007).

So the molecule enters the human food chain through fungi, and everything above the fungi in that chain is borrowing.

The Transporter: Why This Is the Interesting Part

If ergothioneine were merely a dietary antioxidant, it would be one of hundreds and this article would not exist. What makes it distinctive is what your body does with it once it arrives.

There is a dedicated transporter for it.

In 2005, Gründemann and colleagues identified the physiological function of a previously orphan transport protein — OCTN1, encoded by the gene SLC22A4 — and reported that its function is the transport of ergothioneine, with a specificity and efficiency far exceeding its handling of other substrates (Gründemann et al., 2005). The protein has since been widely described in the literature as the ergothioneine transporter (Cheah & Halliwell, 2012).

I want to be careful about how much weight I put on this, because it is the point where an ingredient story usually starts inflating. So let me state the inference and its limits separately.

What is established: humans do not synthesise ergothioneine; it is obtained from diet; and there exists a transport protein whose principal characterised substrate is ergothioneine, expressed in a range of human tissues, which concentrates the molecule inside cells against its concentration gradient. Tissue distribution is not uniform — ergothioneine accumulates preferentially in certain tissues, with those subject to high oxidative demand among those reported to hold higher concentrations (Halliwell, Cheah & Tang, 2018).

What that reasonably suggests: evolution does not usually maintain a dedicated, energy-consuming, substrate-specific transport system for a molecule the organism has no use for. A transporter is not proof of physiological importance — but it is a meaningful hint, and it is the reason ergothioneine has attracted serious research attention rather than remaining a curiosity of fungal chemistry.

What it does not establish: the transporter's existence does not tell us what ergothioneine's physiological role actually is, does not establish that supplementing or applying it produces a clinical benefit, and says nothing whatsoever about hair. Researchers in this field have been explicit that a defined physiological function has not been settled, and some have proposed the term longevity vitamin for nutrients in this general class. That literature is interesting and preliminary, and this article deliberately stays out of it — I am not going to borrow the emotional weight of longevity research to sell a scalp serum.

Oxidative Stress at the Scalp: A Note on Framing

Before going further I want to set the frame carefully, because this is where hair-ingredient writing most often overreaches.

The scalp is a genuinely demanding environment. It is horizontally oriented and therefore receives more cumulative ultraviolet exposure than almost any other skin site; it is where airborne particulate settles; and it sits above follicles that are, during their growth phase, among the most metabolically active structures in the body — and metabolic activity generates reactive oxygen species as an unavoidable byproduct of mitochondrial respiration. Trüeb's review sets out the case that oxidative load is a meaningful factor in hair ageing, and Wood and colleagues documented hydrogen peroxide accumulation and failed methionine sulfoxide repair in the greying human hair follicle — a direct, visible readout of oxidation in this specific tissue (Trüeb, 2009; Wood et al., 2009).

Now the framing discipline. Oxidative stress is part of the environment the follicle lives in. It is not an established cause of pattern hair loss. Androgenetic alopecia is driven by inherited androgen sensitivity at susceptible follicles — a genetic and endocrine story — and no amount of antioxidant chemistry changes a follicle's androgen receptor density.

So when I say I want antioxidant architecture in a scalp formulation, the claim I am making is a modest one: the tissue operates under a measurable oxidative and ultraviolet load, that load is part of the conditions the follicle has to work in, and reducing avoidable burden on the environment is a reasonable formulation objective. That is a claim about conditions, not about cause, and the difference is not a technicality — it is the difference between a defensible sentence and a false one.

Why Formulators Actually Like It: Stability

Here is the practical reason ergothioneine appears in cosmetic formulations, and it is not glamorous.

Most antioxidants are difficult to formulate with, because being easy to oxidise is their entire job description. Ascorbic acid is the standard cautionary tale: highly effective, and notoriously unstable in aqueous solution, degrading with exposure to oxygen, light, heat and metal ions — which is why vitamin C serums brown over time and why so much formulation effort goes into derivatives, low-pH systems, anhydrous vehicles and opaque airless packaging. Thiol antioxidants have their own version of the problem; free thiols oxidise readily to disulfides.

Ergothioneine behaves differently, and the reason is structural. It exists predominantly as a thione rather than a free thiol at physiological pH — the sulfur sits in a tautomeric form that is markedly less prone to spontaneous autoxidation than an ordinary thiol group. It does not readily generate the pro-oxidant behaviour that some antioxidants show in the presence of transition metals, and it is described in the literature as unusually resistant to autoxidation under physiological conditions (Cheah & Halliwell, 2012; Halliwell, Cheah & Tang, 2018).

The practical translation: it is unusually durable. It survives being in a bottle. It is still the molecule you formulated with several months later.

I want to use that word precisely, and flag why. Some copy in this category — including, historically, some of our own — has described ergothioneine as one of nature's most powerful antioxidants. I have stopped using that phrase, because it is a superlative I cannot source. There is no ranked league table of antioxidant potency that I could point you to, powerful has no defined unit, and a claim I cannot support is a claim I should not make. Unusually durable is defensible on stability grounds, it is the property that actually matters in a finished product, and it is what I will say from here on.

That is a small change. I am mentioning it because you should know when a brand quietly revises its own copy, and because it is the kind of thing I would want disclosed to me.

What Is Known About Ergothioneine and Skin

The dermatological literature on ergothioneine is genuine but modest, and I will describe it at exactly the level it exists.

Markova and colleagues reported that skin cells express the OCTN1 transporter and are capable of taking up and using L-ergothioneine as part of their antioxidant defence, with protective effects against ultraviolet-induced oxidative damage in cultured cells (Markova et al., 2009). Subsequent work has examined ergothioneine in the context of cutaneous oxidative stress and photoprotection at the cell and tissue level (review: Molecules, 2023).

That is the honest summary: cell-level and laboratory-level characterisation in skin, showing uptake and antioxidant function. It is a reasonable evidentiary basis for including an antioxidant in a cosmetic formulation. It is not a clinical trial, it is not a hair study, and it does not permit any claim about hair growth.

The follicle-specific literature on ergothioneine is thin. I would rather tell you that than construct an argument out of adjacent findings. Its inclusion in a scalp product rests on cytoprotective chemistry and a well-characterised environmental rationale, not on hair outcome data — and a formulator who tells you otherwise is describing a study that has not been run.

The Honest Limit

Let me put the boundary in one place, unhedged.

Ergothioneine is an antioxidant in a cosmetic product. It is not a drug and it is not a treatment for hair loss.
No antioxidant has been shown to reverse pattern hair loss, and pattern hair loss is not an oxidative disease.
Its hair-specific evidence is limited; its skin-cell and general cytoprotective characterisation is much better.
Its inclusion in a formula is a reasonable environmental measure, in the same category as sun protection and avoiding chronic scalp irritation. It belongs in the supporting cast.

Why include it at all, then? Because a scalp product is a whole formulation, not a single hero ingredient — and the antioxidant column is a real column. The follicle runs hot, sits under UV, and lives in the most exposed skin on the body. I would rather that formula contain a well-characterised, unusually stable antioxidant that skin cells demonstrably take up than not. That is a modest argument, and it is the true one.

The Bottom Line

Ergothioneine is a fungal-origin, histidine-derived, sulfur-containing molecule that humans cannot synthesise and obtain entirely from diet, principally from mushrooms. The most striking fact about it is that the human body maintains a dedicated transport protein — OCTN1, the product of SLC22A4 — whose principal characterised substrate is ergothioneine, and which concentrates it inside cells. Evolution rarely builds and maintains a specific transporter for a molecule it has no use for, which is a strong hint, not a proof.

Its unusual chemical stability — the thione tautomer's resistance to autoxidation — is the practical reason formulators reach for it: it is an antioxidant that survives being in a product.

And the limit is real. Oxidative load is part of the scalp's environment, not a demonstrated cause of pattern hair loss, and no antioxidant has been shown to reverse it. Ergothioneine belongs in a scalp formulation the way good sun habits belong in a skin routine: it addresses the conditions, not the diagnosis.

That is a smaller claim than the ingredient's biology might tempt someone to make. It is also, I think, the more interesting story — a molecule your body cannot build, goes out of its way to keep, and that we still do not fully understand.

Dr. Susan Lin's Clinical Perspective

"The reason I keep coming back to ergothioneine is the transporter. Biology is economical — it does not build and maintain a specific, energy-consuming transport system for a molecule it has no use for. That is not proof of anything, and I am careful to say so, but it is the most interesting hint I know of in the ingredient list of any product I make. What I will not do is convert that hint into a promise. Pattern hair loss is an inherited androgen-sensitivity problem, and no antioxidant on earth changes a follicle's receptor biology. My live copy used to call this molecule one of nature's most powerful antioxidants; I have withdrawn that phrase because I could not source the superlative. Unusually durable, I can defend. That distinction is most of what separates a formulator from a marketer."

— Dr. Susan F. Lin, M.D., Physician Formulator, MD HAIR

Mechanism Spotlight: The Thione Tautomer, and Why Stability Is a Formulation Property Worth Paying For

Most sulfur-containing antioxidants work as thiols — an –SH group that donates a hydrogen atom to neutralise a radical. Glutathione, the cell's principal endogenous antioxidant, works this way. The cost of that chemistry is fragility: free thiols oxidise readily to disulfides on contact with oxygen, and the reaction is accelerated by light, heat and trace transition metals. In a finished cosmetic that means measurable degradation over shelf life.

Ergothioneine is built differently. Its sulfur sits on an imidazole ring, and at physiological pH the molecule exists predominantly in the thione tautomer rather than the thiol form. That tautomeric preference is the whole story: the thione is markedly less susceptible to spontaneous autoxidation, so the molecule does not readily self-destruct in solution. It is also, notably, not prone to the pro-oxidant behaviour some antioxidants exhibit in the presence of iron or copper (Cheah & Halliwell, 2012; Halliwell, Cheah & Tang, 2018).

Why does a formulator care? Because an antioxidant that has oxidised in the bottle is no longer an antioxidant — it is a degradation product with a nice name on the ingredient list. Stability determines whether what you tested is what the customer applies in month nine. Ergothioneine's chemistry means the answer is more often yes.

That is a claim about the molecule's behaviour in a container. It is not a claim about what it does to a follicle, and the two should never be blurred.

MD HAIR Product Recommendation

MD® Follicle Energizer — /products/follicle-energizer

If this article persuaded you of anything, I hope it was the modest version: that the scalp is a chemically demanding environment and that a formulation aimed at it should have a real antioxidant column rather than a decorative one. MD® Follicle Energizer is where ergothioneine sits in the MD® line — formulated alongside Biotinoyl Tripeptide-1, panthenol, niacinamide and biotin in a serum designed for the hairline, crown and part line, applied with a precision brush so the formula lands on scalp rather than on hair.

The reason ergothioneine is in it is the reason given above and no more than that: it is an antioxidant that skin cells have been shown to take up and use in laboratory studies, and it is unusually durable, so it is still doing its job late in the bottle's life. It is a supporting ingredient in the formula's environmental architecture, not its hero, and I am not going to tell you it grows hair.

Drug-free and hormone-free, physician-formulated by Dr. Susan F. Lin, M.D. under the MD® mark (U.S. Reg. No. 4,471,494), and manufactured in FDA-registered, GMP-compliant facilities in the USA. In a 119-day (17-week) Spincontrol North America study of the two-step topical system — n=24, split-scalp design, self-reported questionnaire, no placebo arm — 71% agreed their hair growth had improved. The report's own assessment states that "the satisfaction rate (concerning the overall efficacy) is not significantly validated." Individual results vary; study on file. MD® Follicle Energizer is a cosmetic product and is not intended to diagnose, treat, cure, or prevent any disease.

Alongside it: MD Nutri Hair™ — /products/nutri-hair-supplement

Antioxidant and inflammatory load at the scalp is not only a surface matter, which is why I pair the topical with an internal input rather than asking you to choose. MD Nutri Hair™ is a once-daily capsule built on a 300 mg proprietary blend with niacinamide, vitamin E as alpha tocopheryl acetate, and D-biotin at 0.05 mg — a sensible cofactor dose rather than the megadoses that can interfere with laboratory immunoassays — plus flaxseed powder, lignan powder and lilac. Its lilac component is standardized for verbascoside, a plant phenol which in controlled laboratory studies on human dermal papilla cells induced cell proliferation, prevented testosterone-induced cell death, and reduced the release of pro-inflammatory signals including IL-1α, IL-6, IL-1β and TNF-α (Wisuitiprot et al., 2022). Those are cell studies, not human trials, and the authors state that clinical study is still needed; the material studied was verbascoside from Acanthus, not from lilac — same molecule, different botanical source, and not a study of our own material.

In the MD Nutri Hair™ 30-day in-office consumer use study (30 subjects, self-reported), 95% saw improved hair appearance, 90% reported better manageability, and 75% reported increased fullness. Individual results vary. As a dietary supplement, MD Nutri Hair™ is not intended to diagnose, treat, cure, or prevent any disease, and it is not FDA approved — no dietary supplement is. Label warning: keep out of the reach of children. Do not take if you are pregnant or breast feeding. For adults only; one capsule daily.

A note on assessment window: whatever you use, give it a full hair cycle before you judge it. Ninety days is the minimum honest assessment period for anything in this category, mine included, because a follicle cannot report back faster than it grows.

A note on authenticity: genuine MD HAIR™ and MD Nutri Hair™ products are sold only through mdhair.com, md-factor.com, and the official La Cañada Ventures, Inc. stores on Amazon and Walmart. We cannot verify the storage, handling or lot integrity of units bought anywhere else — which matters more than usual for an antioxidant, since storage conditions are exactly what stability depends on.

Not sure where your hair concern fits? Take the MD HAIR Quiz — a starting point for reasoning, not a diagnosis.

Learn more about scalp environment and follicle health at mdhair.com/pages/scalp-health-guide

References

Gründemann D, Harlfinger S, Golz S, et al. (2005). Discovery of the ergothioneine transporter. Proceedings of the National Academy of Sciences USA, 102(14), 5256–5261. PMID 15795384
Cheah IK, Halliwell B. (2012). Ergothioneine; antioxidant potential, physiological function and role in disease. Biochimica et Biophysica Acta, 1822(5), 784–793. PMID 22001064
Halliwell B, Cheah IK, Tang RMY. (2018). Ergothioneine — a diet-derived antioxidant with therapeutic potential. FEBS Letters, 592(20), 3357–3366. PMID 29851075
Ey J, Schömig E, Taubert D. (2007). Dietary sources and antioxidant effects of ergothioneine. Journal of Agricultural and Food Chemistry, 55(16), 6466–6474. PMID 17616140
Kalaras MD, Richie JP, Calcagnotto A, Beelman RB. (2017). Mushrooms: a rich source of the antioxidants ergothioneine and glutathione. Food Chemistry, 233, 429–433. PMID 28530594
Markova NG, Karaman-Jurukovska N, Dong KK, Damaghi N, Smiles KA, Yarosh DB. (2009). Skin cells and tissue are capable of using L-ergothioneine as an integral component of their antioxidant defense system. Free Radical Biology and Medicine, 46(8), 1168–1176. PMID 19439218
Trüeb RM. (2009). Oxidative stress in ageing of hair. International Journal of Trichology, 1(1), 6–14. PMID 20805969
Wood JM, Decker H, Hartmann H, et al. (2009). Senile hair graying: H2O2-mediated oxidative stress affects human hair color by blunting methionine sulfoxide repair. FASEB Journal, 23(7), 2065–2075. PMID 19237503
Safe and effective antioxidant: the biological mechanism and potential pathways of ergothioneine in the skin. Molecules, 28(4), 1648 (2023). doi:10.3390/molecules28041648
Wisuitiprot V, Ingkaninan K, Chakkavittumrong P, Wisuitiprot W, Neungchamnong N, Chantakul R, Waranuch N. (2022). Effects of Acanthus ebracteatus Vahl. extract and verbascoside on human dermal papilla and murine macrophage. Scientific Reports, 12(1), 1491. PMID 35087085
Spincontrol North America. 119-day (17-week) consumer study of the MD® two-step topical system; n=24, split-scalp design, self-reported questionnaire, no placebo arm. Report on file, La Cañada Ventures, Inc.
30-day in-office consumer use study — MD Nutri Hair™ (30 subjects, self-reported). Report on file, La Cañada Ventures, Inc.
U.S. Food and Drug Administration. FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. fda.gov

Dr. Susan F. Lin, M.D. is the physician formulator behind MD HAIR and MD Nutri Hair™, product lines of La Cañada Ventures, Inc. — physician-formulated since 2008 under the MD® mark (U.S. Reg. No. 4,471,494). She trained at Boston University School of Medicine and is board-certified in Obstetrics & Gynecology and in Anti-Aging Medicine (A4M).

MD® products are cosmetics and dietary supplements manufactured in FDA-registered, GMP-compliant facilities. Facility registration is not product approval: MD® products are not FDA approved, and no cosmetic or dietary supplement is. Individual results vary. MD Nutri Hair™ is a dietary supplement. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Because there are no clinical data in pregnant or breastfeeding women, we do not advocate using MD HAIR products during pregnancy or lactation.

In vitro and cell-culture findings described in this article are laboratory characterisations of ingredient behaviour, not clinical outcomes in people. This article is for educational purposes and does not constitute medical advice. Consult your own physician for personalized guidance, and do not start, stop, or change any medication without consulting your prescriber.

Explore more in our Verbascoside & Lilac Science series at mdhair.com/pages/lilac-verbascoside-science