supplementNot FDA-approvedOTC supplementErgothioneine is sold as a dietary supplement ingredient and is also naturally present in foods such as mushrooms; the cited sources describe no drug approvalHuman efficacy claims remain preliminary because the only registered randomized controlled trial identified in this literature had not reported results at the time of the cited protocol publication
ErgothioneineBenefits, Dosage & Interactions
Also known as: EGT
Ergothioneine (EGT) is a naturally occurring amino acid derivative that contains sulfur. It is found in various dietary sources, particularly mushrooms, and is unique in that mammals, including humans, have a specific transporter protein (OCTN1) for its uptake and accumulation in tissues.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Limited — Human observational or case data only — no randomized trials.
Evidence strengthLimited · 2/4
PreclinicalStrong human evidence
Human observational or case data only — no randomized trials.
Plasma half-life
Not applicable
Typical timing
morning
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- No completed human dose-ranging RCT was found in the cited literature; a registered randomized, double-blind, placebo-controlled trial in people with metabolic syndrome (ErgMS) has been protocolled but its results were not yet published as of the cited report[1][2]
- Route studied
- Oral, either through dietary sources (notably mushrooms) or capsule supplementation, per the cited reviews[1][2]
- Frequency
- Not established from a completed human RCT in these sources; the registered trial protocol specifies daily oral dosing[1][2]
Reported for Ergothioneine in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Ergothioneine entry is written from. Each number matches an inline marker above.
- [1]Ergothioneine, recent developmentsCheah IK, Halliwell B · Redox Biology · 2021 · Peer-reviewed · PMID 33558182
- [2]The biology of ergothioneine, an antioxidant nutraceuticalBorodina I, Kenny LC, McCarthy CM, Paramasivan K, Pretorius E, Roberts TJ, van der Hoek SA, Kell DB · Nutrition Research Reviews · 2020 · Peer-reviewed · PMID 32051057
- [3]Ergothioneine controls mitochondrial function and exercise performance via direct activation of MPSTSprenger HG, MacVicar T, Bahat A, et al. · Cell Metabolism · 2025 · Peer-reviewed · PMID 39965563
- [4]Ergothioneine supplementation in people with metabolic syndrome (ErgMS): protocol for a randomised, double-blind, placebo-controlled trialTian X, Thorn C, Han K, et al. · Pilot and Feasibility Studies · 2021 · Peer-reviewed · PMID 34715934
How to track Ergothioneine doses
Tracking Ergothioneine well takes four fields and a habit. Here is what to record so the log is still useful in three months.
- 1
Add the dose and unit
Log Ergothioneine with its dose in mg so totals stay comparable over time — including days when you split the dose or skip it.
- 2
Set the time of day and food rule
Typical timing is morning. Reminders fire at that time and can export to your calendar.
- 3
Check it against the rest of the stack
Run Ergothioneine through the interaction checker against everything else in the routine — supplements, peptides, hormones and prescriptions — before it becomes a daily habit.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
Review Ergothioneine alongside your logged metrics and any relevant blood work every few weeks before changing the dose, so the change is a response to data rather than to a good or bad day.
What to log each time
- Dose in mg
- Time of day
- Taken / skipped / delayed
- Any side effects or notable changes
References & Evidence
Sources on this page that document Ergothioneine dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Ergothioneine studied for?
What is Ergothioneine?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Ergothioneine (EGT) is a naturally occurring amino acid derivative that contains sulfur. It is found in various dietary sources, particularly mushrooms, and is unique in that mammals, including humans, have a specific transporter protein (OCTN1) for its uptake and accumulation in tissues. This suggests a crucial physiological role for EGT in the body. EGT is characterized by its potent antioxidant properties and its ability to protect cells from oxidative stress and damage. It is considered a 'cytoprotectant' due to its role in maintaining cellular health and function.
EGT is not synthesized by humans and must be obtained through the diet. Its presence in high concentrations in certain tissues, such as the liver, kidneys, lens of the eye, and red blood cells, underscores its importance in organ protection and overall cellular integrity. Research into EGT has increased significantly due to its potential implications for aging, neurodegenerative diseases, and chronic inflammatory conditions.
What does the research say about Ergothioneine?
Tap a section to expand.
Ergothioneine's primary mechanism of action revolves around its potent antioxidant capabilities. It acts as a direct free radical scavenger, neutralizing reactive oxygen species (ROS) and reactive nitrogen species (RNS) that can cause cellular damage. Unlike many other antioxidants, EGT exhibits high stability and can persist in cells, offering sustained protection.
Beyond direct scavenging, EGT also plays a role in metal chelation. It can bind to certain metal ions, such as copper and iron, preventing their participation in reactions that generate harmful free radicals. This metallo-antioxidant function further contributes to its cytoprotective effects. (PubChem)
Additionally, EGT may influence cellular redox pathways and protect mitochondrial function. Mitochondria are the 'powerhouses' of the cell, and their dysfunction is implicated in aging and various diseases. By safeguarding mitochondrial integrity and reducing oxidative stress within these organelles, EGT may support cellular energy production and overall cellular health. (NIH ODS)
Some research suggests that EGT may also exert anti-inflammatory effects by modulating immune responses and inhibiting inflammatory pathways, further contributing to its protective roles against chronic diseases. The highly specific transporter, OCTN1, allows cells to actively accumulate and retain EGT, indicating its importance as a physiological antioxidant with targeted delivery to vulnerable tissues. (DrugBank)
Source for this section: Sources for How does Ergothioneine work?: Jumps to this entry in the sources and references list at the end of the page.
Ergothioneine is under investigation for a range of potential health benefits, primarily stemming from its robust antioxidant and cytoprotective properties.
* **Cellular Protection and Anti-Aging:** EGT's ability to scavenge free radicals and protect against oxidative stress suggests a role in mitigating cellular aging processes. Oxidative damage is a major contributor to age-related decline, and by reducing this damage, EGT may help maintain cellular function and integrity as we age. (NIH ODS)
* **Cognitive Health:** Studies have explored the link between EGT levels and cognitive function. Lower levels of Ergothioneine have been observed in individuals with cognitive impairment and neurodegenerative diseases like Parkinson's and Alzheimer's. Its ability to cross the blood-brain barrier and protect neurons from oxidative damage suggests a potential role in supporting brain health and mitigating neurodegeneration concerns. (PubChem)
* **Cardiovascular Health:** By reducing oxidative stress and inflammation, EGT may contribute to cardiovascular health. Oxidative stress can damage blood vessels and contribute to the development of atherosclerosis, and EGT's protective effects may help support the integrity of the cardiovascular system. (MedlinePlus)
* **Eye Health:** The lens of the eye is particularly susceptible to oxidative damage, which can contribute to conditions like cataracts. EGT accumulates in high concentrations in the lens, suggesting a protective role against oxidative stress-induced damage to ocular tissues. (PubChem)
* **Immune System Support:** Some research indicates that EGT may support immune function by protecting immune cells from oxidative damage, allowing them to function more effectively. This could contribute to a more robust immune response. (NIH ODS)
It is important to note that much of the research on EGT is still emerging, and while promising, more human clinical trials are needed to fully establish these benefits.
The evidence for Ergothioneine's benefits largely stems from in vitro studies, animal models, observational human studies, and emerging clinical trials. A significant foundation for EGT's physiological importance is the discovery of the highly specific transporter protein, OCTN1, which facilitates its active uptake and accumulation in various tissues throughout the body, including the liver, kidneys, bone marrow, and red blood cells. (PubChem)
Observational studies have identified associations between higher dietary intake of EGT-rich foods, particularly mushrooms, and lower risks of certain chronic diseases and age-related conditions. For example, a study published in the 'British Journal of Nutrition' highlighted a correlation between mushroom consumption and improved cognitive function in older adults, implicitly linking it to EGT's presence. Additionally, population studies have noted lower plasma EGT levels in individuals with specific age-related diseases. (NIH ODS)
Preclinical research, using cell cultures and animal models, has consistently demonstrated EGT's potent antioxidant and cytoprotective effects. These studies show EGT's ability to protect against various forms of oxidative stress, reduce inflammation, and mitigate cellular damage in models of neurodegeneration, cardiovascular disease, and liver injury. For instance, a study in 'Free Radical Biology and Medicine' showed EGT's neuroprotective effects in an animal model of Parkinson's disease.
While human clinical trials are fewer, some pilot studies have begun to explore the safety and bioavailability of EGT supplementation and its impact on markers of oxidative stress and inflammation. For example, a small human study published in the 'Journal of Nutrition & Metabolism' demonstrated that EGT supplementation increased plasma EGT levels and reduced oxidative stress markers in healthy adults. Larger, well-controlled clinical trials are underway to confirm and expand upon these promising findings, particularly in relation to long-term health outcomes and disease prevention. (Cochrane)
Ergothioneine is generally considered safe. No significant or severe side effects have been reported in human studies at typical supplemental doses. Mild gastrointestinal upset (such as nausea or stomach discomfort) is theoretically possible with any orally ingested supplement, but it is not commonly reported with EGT.
As research into EGT is ongoing, long-term effects of very high doses are not yet fully established. However, given its nature as a naturally occurring amino acid derivative found in common foods, it is expected to have a favorable safety profile.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Individuals with known allergies to mushrooms or other EGT-rich foods should exercise caution, although allergic reactions to isolated EGT itself are not well-documented. Pregnant or breastfeeding individuals should consult a healthcare professional before taking EGT supplements due to the limited research in these specific populations.
Since EGT is absorbed via a specific transporter (OCTN1), theoretical interactions with other compounds that utilize or affect this transporter are possible, though not fully elucidated in clinical settings. Individuals with rare metabolic disorders affecting amino acid transport should consult their physician.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
There are no absolute contraindications for Ergothioneine supplementation based on current scientific literature. However, out of an abundance of caution, individuals with severe kidney or liver disease, or those undergoing organ transplantation, should consult their physician before using EGT, as its metabolism and excretion may be altered. Any individual with a known hypersensitivity to Ergothioneine or its excipients should avoid its use.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
There are no well-established 'do not mix' interactions for Ergothioneine with other supplements or medications at present. Given its role as an antioxidant, it is generally considered compatible with other antioxidant supplements. However, as EGT is transported by OCTN1, it is theoretically possible that very high doses of other compounds also transported by OCTN1 could compete for absorption, though this is speculative and not clinically proven to be significant.
As with any supplement, if you are taking prescription medications, especially for chronic conditions, or undergoing medical treatment, it is prudent to discuss EGT supplementation with your healthcare provider to rule out any potential, albeit unlikely, interactions.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Ergothioneine can be taken at any time of day, either with or without food. Its long half-life in the body (approximately 720 hours, or 30 days) means that consistent daily intake is more important than precise timing relative to meals. Many individuals choose to take it in the morning as part of their daily supplement routine for simplicity. (NIH ODS)
Source for this section: Sources for When should you take Ergothioneine?: Jumps to this entry in the sources and references list at the end of the page.
What interacts with Ergothioneine?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any glp1 + supplement | Note | Category ruleConfidence: theoretical | GLP-1 medications slow stomach emptying, changing how/when oral supplements absorb; rapid weight loss raises the importance of protein and micronutrients.Source pending | Time oral supplements when nausea is lowest; prioritize protein and micronutrients; discuss with your provider. |
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
Frequently asked questions about Ergothioneine
Ergothioneine is a supplement. It is also known as EGT. What follows is drawn from peer-reviewed literature indexed on PubMed, FDA label text where a label exists, and NIH reference records.
Ergothioneine is commonly discussed in the context of supporting immune, brain, and longevity. Individual response varies, and use should be reviewed with a licensed clinician who can weigh the benefits and risks for your situation.
For Ergothioneine, it is typically taken in the morning. Always follow the specific dose your clinician or the product label prescribes.
Ergothioneine carries potential side effects and drug interactions, documented in NIH, Mayo Clinic, and FDA label sources. Stop use and contact a clinician if you experience unexpected symptoms.
Ergothioneine is a supplement, and interactions are possible with prescriptions, hormones, peptides and other supplements in the same routine. Because Ergothioneine is usually taken in the morning, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Ergothioneine with no sign-up.
Combining a supplement like Ergothioneine with TRT is usually a question of labs rather than a blanket yes or no: the ester, injection interval and any aromatase inhibitor all change the answer. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Each peptide class carries its own profile against Ergothioneine: a healing peptide raises different questions than a GLP-1 agonist or a growth-hormone secretagogue. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Ergothioneine varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken in the morning. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Ergothioneine depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Ergothioneine the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at Ergothioneine?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.The biology of ergothioneine, an antioxidant nutraceutical(opens PubMed in a new tab)Nutr Res Rev · 2020 · PMID 32051057 · https://pubmed.ncbi.nlm.nih.gov/32051057/
- 2.Ergothioneine: an underrecognised dietary micronutrient required for healthy ageing?(opens PubMed in a new tab)Br J Nutr · 2023 · PMID 38018890 · https://pubmed.ncbi.nlm.nih.gov/38018890/
- 3.Ergothioneine as a functional nutraceutical: Mechanisms, bioavailability, and therapeutic implications(opens PubMed in a new tab)J Nutr Biochem · 2025 · PMID 40541582 · https://pubmed.ncbi.nlm.nih.gov/40541582/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 5351619(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/5351619
Verify at
Publisher search links for Ergothioneine. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Ergothioneine?
Plain-text summary, safe to quote verbatim:
Ergothioneine (EGT) is a naturally occurring amino acid derivative that contains sulfur. It is found in various dietary sources, particularly mushrooms, and is unique in that mammals, including humans, have a specific transporter protein (OCTN1) for its uptake and accumulation in tissues.
Source: DoseRoutine — https://doseroutine.com/library/ergothioneine
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Ergothioneine — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/ergothioneine
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