Ergosterol Peroxide

Ergosterol Peroxide at a Glance

Ergosterol peroxide (5α,8α-epidioxy-22E-ergosta-6,22-dien-3β-ol) is the oxidised derivative of ergosterol — the parent fungal membrane sterol with a 5,8-endoperoxide bridge added across its B-ring. That bridge is the whole story: it forms when UV light or singlet oxygen oxidises ergosterol’s conjugated 5,7-diene, and it is the presumed pharmacophore behind everything interesting this molecule does ^{1,6Reference 1Rangsinth P et al. · 2023Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushroomsView study →Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

It is a widespread sterol of medicinal mushrooms — reishi (Ganoderma lucidum), cordyceps, chaga (Inonotus obliquus), Antrodia and many other Basidiomycetes accumulate it as the oxidised form of their abundant ergosterol ^{1,2Reference 1Rangsinth P et al. · 2023Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushroomsView study →Reference 2Takei T et al. · 2005Ergosterol peroxide, an apoptosis-inducing component isolated from Sarcodon aspratus (Berk.) SView study →}. And this is the key point for reading it alongside the parent page: ergosterol peroxide carries most of the “mushroom ergosterol” anticancer and anti-inflammatory signal — the antitumour, pro-apoptotic, anti-angiogenic and anti-inflammatory results that are frequently mis-credited to ergosterol itself actually belong to this oxidised relative ^{3,4,5Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}.

The honest headline sits underneath that: the oxidised sterol that carries most of the mushroom anticancer signal, but the evidence is preclinical and the parent sterol often gets the credit. Every result below is in-vitro (isolated compound at micromolar concentrations on cancer or immune cell lines) or in mice — there are no human trials — and the oral bioavailability of a lipophilic sterol is an open question the recent preclinical work is only beginning to address ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

The Oxidised Sterol That Carries the Signal

To read this correctly you have to separate two molecules that the literature routinely blurs. Ergosterol is the intact fungal membrane sterol — provitamin D2, the antifungal drug target — and its own bioactivity is thin ^{1Reference 1Rangsinth P et al. · 2023Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushroomsView study →}. Ergosterol peroxide is what you get when that sterol is oxidised at the 5,7-diene: molecular oxygen (as singlet oxygen, typically photosensitised by UV) adds across the ring to give a 5,8-endoperoxide, converting an ordinary sterol into a reactive one ^{1,6Reference 1Rangsinth P et al. · 2023Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushroomsView study →Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

That single modification is why the mushroom “anticancer sterol” story is really a story about the derivative, not the parent. When reviews and marketing credit Ganoderma or chaga’s antitumour activity to “ergosterol,” the isolated-compound experiments underneath almost always used ergosterol peroxide: it is the fraction that induces apoptosis in cancer lines, suppresses inflammatory macrophages, and lowers VEGF ^{3,4,5Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}. The parent ergosterol page makes the same point from the other side — that its anticancer signal “largely belongs to ergosterol peroxide” — and that molecule is documented here.

Because it forms spontaneously from ergosterol under light and air, ergosterol peroxide is also partly an artefact question: some of what is extracted from dried, UV-exposed or aged fungal material is peroxide generated during handling, not made by the living fungus. That does not undo the pharmacology — the isolated compound is genuinely active — but it means “how much the intact mushroom delivers” is even less certain than the cell data suggest.

The Endoperoxide Pharmacophore

The reason a small structural change matters so much is that the 5,8-endoperoxide bridge is a reactive motif, not a passive decoration. A peroxide (O–O) bond embedded in a ring is chemically primed to break and generate radicals or oxidising species — the same class of reactive endoperoxide that makes the antimalarial artemisinin work ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}. On that reading, ergosterol peroxide is best understood as an artemisinin-like sterol: a lipophilic scaffold that carries a reactive peroxide into cells.

This framing does real explanatory work across the pharmacology below. Several of the effects — ROS-dependent apoptosis in cancer cells, oxidative disruption of tumour and endothelial signalling — are consistent with the endoperoxide acting as an intracellular pro-oxidant trigger rather than the sterol acting as a classical receptor ligand ^{4,5Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}. It also predicts the molecule’s main liabilities: a reactive O–O bond is a stability concern (heat, light and reductants can degrade it) and a selectivity question (why tumour and immune cells, rather than all cells). The recent preclinical programme that made synthetic derivatives of ergosterol peroxide was aimed squarely at these problems — improving aqueous solubility and drug-likeness while keeping the peroxide pharmacophore ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

What It's Used For

Ergosterol peroxide’s pharmacology is broad on paper but uniformly preclinical: a substantial isolated-compound literature across cancer, inflammation, angiogenesis and viral models, with no human data anywhere. The load-bearing caveat is the one carried from the parent page — this is the molecule that earns the mushroom anticancer reputation, but only in cells and mice.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. Every row rests on isolated-compound cell and mouse work with no human trials, so scores stay low by design; read the per-row basis.

01Anticancer / AntiproliferativeShaky42%Apoptosis + cell-cycle arrest across several cancer lines + mouse tumour models ^{2,3,4,5,6Reference 2Takei T et al. · 2005Ergosterol peroxide, an apoptosis-inducing component isolated from Sarcodon aspratus (Berk.) SView study →Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}

02Anti-inflammatoryShaky34%NF-κB / MyD88 suppression in LPS macrophages; RIG-I block ^{3,7Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 7Zhou B et al. · 2019Ergosterol peroxide suppresses influenza A virus-induced pro-inflammatory response and apoptosis by blocking RIG-I signalingView study →}

03Anti-angiogenicShaky30%STAT3↓ / VEGF↓ in U266 myeloma cells + mice ^{5Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}

04Antiviral / AntiparasiticShaky20%Influenza via RIG-I; older antiviral/trypanocidal reports ^{7Reference 7Zhou B et al. · 2019Ergosterol peroxide suppresses influenza A virus-induced pro-inflammatory response and apoptosis by blocking RIG-I signalingView study →}

Mechanisms

The load-bearing idea is the top row: a single reactive endoperoxide distinguishes this molecule from inert ergosterol and plausibly underlies the ROS-dependent apoptosis and the anti-inflammatory and anti-angiogenic signalling below. Everything here is preclinical.

Pharmacokinetics

For most of its history ergosterol peroxide’s ADME was simply unstudied — the pharmacology sits on μM cell exposures and injected mouse doses, not on any characterised oral disposition. The most useful data come from the 2024 preclinical programme, which found the compound metabolically stable in liver microsomes and plasma and well tolerated in mice (no toxicity at escalating doses up to ~500 mg/kg), while noting that its poor aqueous solubility is the practical limit on developing it — the reason the same work synthesised more soluble derivatives ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}. Two consequences follow. First, as with the parent sterol, in-vitro potency likely overstates what an eaten mushroom delivers systemically, because a lipophilic sterol is not readily absorbed intact. Second, the reactive endoperoxide is itself a stability variable — heat, light and reducing conditions can degrade it — so formulation, not just dose, governs exposure. Robust human PK does not exist.

Clinical Trials

There are no clinical trials of ergosterol peroxide in any indication. The entire evidence base is isolated-compound cell work and mouse models.

Last checked: July 2026.

Isolate vs. Plant Studies

The split here is unusually clean and worth stating plainly: essentially all of the pharmacology is the isolated molecule. Ergosterol peroxide has been tested as a purified compound in radical-driven apoptosis assays, on cancer cell lines, in LPS-stimulated macrophages, on endothelial tube-formation, and in tumour-bearing mice ^{2,3,4,5,6,7Reference 2Takei T et al. · 2005Ergosterol peroxide, an apoptosis-inducing component isolated from Sarcodon aspratus (Berk.) SView study →Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →Reference 7Zhou B et al. · 2019Ergosterol peroxide suppresses influenza A virus-induced pro-inflammatory response and apoptosis by blocking RIG-I signalingView study →} — a genuinely strong isolate mechanism base, and a completely silent human one.

In its source mushrooms the compound is one contributor among many. Reishi, chaga, Cordyceps and Antrodia are complex matrices of triterpenes, polysaccharides (β-glucans) and multiple sterols, so a whole-mushroom effect cannot be attributed to ergosterol peroxide alone even when the isolate studies were designed to probe its share ^{1,3Reference 1Rangsinth P et al. · 2023Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushroomsView study →Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →}. The transferability caveat is therefore doubled: from cell line to whole mushroom (undercut by the poor absorption expected of a lipophilic sterol ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}), and from the reactive peroxide to the far less active parent ergosterol that often gets the credit.

Prevalence in Nature

Ergosterol peroxide is widespread across the higher fungi as the oxidised counterpart of their dominant membrane sterol. It has been isolated from a long list of medicinal and edible mushrooms — reishi (Ganoderma lucidum), cordyceps, chaga (Inonotus obliquus), Antrodia camphorata, oyster mushroom (Pleurotus ostreatus), Sarcodon aspratus — as well as from marine and endophytic fungi such as Phoma and Paecilomyces ^{2,3,5Reference 2Takei T et al. · 2005Ergosterol peroxide, an apoptosis-inducing component isolated from Sarcodon aspratus (Berk.) SView study →Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}. Wherever there is abundant ergosterol and an oxidising environment, some peroxide tends to accompany it.

Its distribution is entangled with how it forms. Because ergosterol’s 5,7-diene is oxidised to the 5,8-endoperoxide by singlet oxygen under UV light (and slowly by air), part of the ergosterol peroxide recovered from dried, sun- or lab-exposed and aged fungal material is generated during harvest and processing rather than made by the living fungus. This is the same photochemistry that, on a different reaction path, turns ergosterol into vitamin D2 — here the oxygen adds instead of the ring opening. As a result the compound is rarely quantified as a fixed “content”; reported levels depend heavily on species, tissue and handling.

Quantitative source levels are not well established and are tracked for a later pass.

Discovery & Synthesis

Ergosterol peroxide entered the literature as an oxidation product of ergosterol rather than as a headline discovery of its own — it was characterised through twentieth-century work on mushroom and fungal sterols, in which the 5,8-endoperoxide of ergosterol was recognised as a recurring natural sterol and as the photo-oxidation product of the parent. No single “first isolation” date stands out; the molecule’s identity is inseparable from ergosterol’s.

Preparation reflects that origin. The compound can be extracted from fungal biomass (reishi, chaga, Antrodia and others), but it is also made directly by photo-oxygenation of ergosterol — irradiating ergosterol in the presence of oxygen and a photosensitiser adds singlet oxygen across the 5,7-diene to give the 5,8-endoperoxide, the same reaction that happens incidentally during UV exposure of mushrooms. The recent medicinal-chemistry interest has gone the other way, using ergosterol peroxide as a scaffold for synthetic derivatives designed to raise its aqueous solubility and drug-likeness while retaining the reactive peroxide ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

Patents: not yet researched.

Toxicity & Safety

Ergosterol peroxide carries a low flag, but for a specific, evidence-limited reason: it is a normal constituent of edible and medicinal mushrooms long consumed by humans, and in the one preclinical toxicity assessment available it was well tolerated in mice with no observed toxicity at doses up to ~500 mg/kg, including no cardio- or hepatotoxic signal in the accompanying assays ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}. In the cell literature it appears as a selective pro-apoptotic agent — active against cancer and inflammatory cells at concentrations far above anything an eaten mushroom delivers ^{3,5Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →Reference 5Rhee YH et al. · 2012Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cellsView study →}.

The caveats are the honest ones for a preclinical molecule:

Safety at a Glance

✅ Low / no toxicity

• A dietary mushroom sterol, well tolerated in the one animal study. Present in commonly eaten and medicinal mushrooms; no toxicity in mice up to ~500 mg/kg, and no established toxicity for the isolate ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.
• Safety rests entirely on preclinical data. There are no human safety trials, and no characterised repeat-dose, genotoxicity or reproductive package for the pure compound ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.
• It carries a reactive endoperoxide. The pharmacophore is a pro-oxidant motif; the same reactivity behind its anticancer effect is why selectivity and off-target oxidative effects at medicinal (not dietary) doses are unquantified ^{4,6Reference 4Li X et al. · 2016Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cellsView study →Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.
• Extract fractions ≠ the food. The bioactivity data use purified compound at high in-vitro concentrations; they do not describe culinary mushroom intake ^{3Reference 3Kobori M et al. · 2007Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cellsView study →}.

Pregnancy and lactation are decided on the herb or supplement page where intake is chosen, not on this molecule page; no isolate-specific reproductive dataset is characterised here for ergosterol peroxide, and no verdict is issued.

Dosage

There is no established or recommended human dose for ergosterol peroxide. It has never been tested in people, and its lipophilic-sterol chemistry means an oral “dose” cannot be translated from the preclinical work with confidence ^{6Reference 6Ling T et al. · 2024Early preclinical studies of ergosterol peroxide and biological evaluation of its derivativesView study →}.

The figures that exist are research values, not recommendations:

Practical human exposure is dietary — via medicinal and edible mushrooms (reishi, cordyceps, chaga and others) — where the compound is one of many constituents and its systemic absorption is uncertain. These are research figures, not a personal recommendation.

References

1. Rangsinth P, et al. (2023). Potential beneficial effects and pharmacological properties of ergosterol, a common bioactive compound in edible mushrooms. Foods. https://pubmed.ncbi.nlm.nih.gov/37444267/
2. Takei T, Yoshida M, Ohnishi-Kameyama M, Kobori M (2005). Ergosterol peroxide, an apoptosis-inducing component isolated from Sarcodon aspratus (Berk.) S. Ito. Bioscience, Biotechnology, and Biochemistry. https://pubmed.ncbi.nlm.nih.gov/15665489/
3. Kobori M, Yoshida M, Ohnishi-Kameyama M, Shinmoto H (2007). Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cells. British Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/17160010/
4. Li X, Wu Q, Bu M, et al. (2016). Ergosterol peroxide activates Foxo3-mediated cell death signaling by inhibiting AKT and c-Myc in human hepatocellular carcinoma cells. Oncotarget. https://pubmed.ncbi.nlm.nih.gov/27058618/
5. Rhee YH, Jeong SJ, Lee HJ, et al. (2012). Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cells. BMC Cancer. https://pubmed.ncbi.nlm.nih.gov/22260501/
6. Ling T, Arroyo-Cruz LV, Smither WR, et al. (2024). Early preclinical studies of ergosterol peroxide and biological evaluation of its derivatives. ACS Omega. https://pubmed.ncbi.nlm.nih.gov/39246459/
7. Zhou B, Liang X, Feng Q, et al. (2019). Ergosterol peroxide suppresses influenza A virus-induced pro-inflammatory response and apoptosis by blocking RIG-I signaling. European Journal of Pharmacology. https://pubmed.ncbi.nlm.nih.gov/31323223/

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