GeneIII® L-Ergothioneine
Clinically studied to support sleep, energy, and cognitive health, with 30mg of 99.99% pure L-Ergothioneine in every capsule.*
How Benefits Build
Over Time
$15M+
Invested in
Clinical Studies
180K+
Customers
Worldwide
100+
Peer-Reviewed
Studies on EGT
30+
International
Patents
Uncompromising Quality
At GeneIII, we hold ourselves to the highest standards in research, quality, and safety.
See What Sets
GeneIII Apart
Frequently Asked Questions
Clinical Study Results
- Deeper sleep*
- Natural energy*
- Mental clarity*
Subscribe & Save:
What Is GeneIII® L-Ergothioneine?
L-Ergothioneine (EGT) is a naturally occurring compound found in foods like mushrooms. Your body has a dedicated transporter called OCTN1 that actively absorbs and retains it.
Research suggests EGT accumulates in tissues exposed to high oxidative stress, including the brain and liver, where it helps support cellular health and resilience.*
GeneIII produces EGT in-house using proprietary, patented fermentation and purifies it to 99.99% purity, the highest on the market. Each capsule provides 30 mg of EGT.
Key Ingredients
L-Ergothioneine — 30 mg
Pure L-Ergothioneine produced through GeneIII’s proprietary fermentation process.
Clean formulation:
✓ Vegan
✓ Gluten-free
✓ No artificial colors
✓ No artificial sweeteners
✓ No artificial preservatives
✓ Free from dairy, shellfish, peanuts, tree nuts, and eggs
How to Take
Take 1 capsule daily, with or without food. Many people prefer taking it in the morning as part of their daily routine.
For best results, take consistently for 3 months or longer.
What to Expect
Consistency matters with L-Ergothioneine.
In GeneIII® human studies, improvements in energy, fatigue, overall wellbeing, and key measures of liver and ovarian health were seen with consistent use ranging from 30 days to several months.*
For best results, make GeneIII® part of your daily routine.
Individual results may vary.
Quality & Testing
Quality is controlled at every step, with rigorous testing to verify purity, identity, and consistency before each batch is released.
✓ Third-party lab tested
✓ Manufactured in a cGMP-compliant facility
✓ FDA GRAS Notice GRN 001270 for GeneIII® L-Ergothioneine
✓ Certificates of Analysis available
What is L-Ergothioneine?
L-Ergothioneine (EGT) is a rare and powerful antioxidant naturally found in mushrooms. Unlike most antioxidants, your body has a dedicated transporter called OCTN1 specifically designed to absorb and retain it in areas with high oxidative stress, including the brain, liver, eyes, and skin.
Research suggests L-Ergothioneine plays an important role in supporting cellular health, healthy aging, cognitive function, and resilience against everyday oxidative stress.
What are the benefits of L-Ergothioneine?
L-Ergothioneine helps protect cells from oxidative damage and has been studied for its role in cognitive health, sleep, energy, liver health, ovarian health, and healthy aging.* Rather than acting like a stimulant or providing an immediate boost, EGT supports cellular health over time.
Can’t I just get L-Ergothioneine from food?
You can, but typically only in very small amounts.
Certain mushrooms are among the richest natural sources, but their EGT content depends on species, growing conditions, storage, and preparation. To reach the amount found in a single GeneIII capsule, you may need to consume several hundred grams of mushrooms daily.
Supplementation provides a simple way to get a consistent, measured amount every day.
What makes GeneIII different from other L-Ergothioneine supplements?
Unlike brands that simply source L-Ergothioneine, we manufacture our own GeneIII® L-Ergothioneine, giving us greater control over purity, consistency, and quality from batch to batch. GeneIII® is rigorously tested, third-party verified, and successfully notified to the FDA as a GRAS (Generally Recognized as Safe) ingredient. Not every L-Ergothioneine ingredient on the market comes with the same level of quality control and safety evaluation.
Just as importantly, GeneIII® is the specific L-Ergothioneine used in our human clinical research—not simply generic L-Ergothioneine. So the ingredient being studied is the same ingredient you’re actually taking.
Is GeneIII® L-Ergothioneine made from mushrooms?
No. GeneIII® is made through precision fermentation, not mushroom extraction. The amount of EGT in mushrooms can vary widely, and extracting it also pulls along many other unwanted components. Fermentation gives us much tighter control over how EGT is produced, so we can deliver a consistent, highly purified 99.99% L-Ergothioneine in every batch.
Can I take GeneIII with my other supplements?
GeneIII can generally be incorporated into an existing supplement routine. If you take medications, are pregnant or breastfeeding, or have a medical condition, consult your healthcare professional before use.
How long does it take to notice benefits from L-Ergothioneine?
L-Ergothioneine isn't an instant-effect supplement, and the timeline can vary by individual. Human research has evaluated outcomes after supplementation over several weeks or longer. Some people may notice benefits within a few weeks, while others may take longer. Like many supplements, L-Ergothioneine works best when taken regularly over time.
When is the best time to take L-Ergothioneine?
L-Ergothioneine can be taken at any time of day, with or without food. Some people prefer taking it in the morning, but there is no required time. For best results, L-Ergothioneine should be taken consistently as part of a daily routine.
How much L-Ergothioneine should I take?
Each GeneIII capsule contains 30 mg of L-Ergothioneine. We recommend taking 1–2 capsules daily, or as directed by your healthcare professional.
Is GeneIII third-party tested?
Yes. GeneIII undergoes third-party laboratory testing to help verify the identity, purity, and quality of our product before it reaches you. We also maintain Certificates of Analysis for added transparency.
GeneIII vs Other EGT
EGT vs Other Antioxidants
EGT
Glutathione
CoQ10
Resveratrol
Pulled directly into cells through a dedicated transporter, OCTN1
Concentrates in the brain, liver, eyes & other high-stress tissues
Crosses the blood-brain barrier
Retained in the body for weeks to months
Backed by human clinical studies
Partial
Partial
Unclear
Unclear
EGT vs Other Antioxidants
GeneIII vs Other EGT
In-House Manufacturing
FDA GRAS (GRN No. 1270)
99.99% Pure EGT
30+ International Patents
Investigator-Initiated Clinical Trials
Often ≤99%
Other
Brands
Ovarian Health
Liver Health
Postpartum Health
Energy & Fatigue
After 30 days, participants reported significant improvements in how they felt day to day— from their energy during the day to their overall physical wellbeing.*
+51.6% ↑
+39.0% ↑
Daytime Energy
Physical Wellbeing
Baseline
After 30 Days
Registered Trial: ChiCTR2400093739
Ovarian Health
Liver Health
Postpartum Health
Energy & Fatigue
After taking 60 mg/day of GeneIII® for 30 days, participants showed improvements in key liver health markers.*
-21.0% ↓
-19.6% ↓
ALT
(U/L)
AST
(U/L)
Baseline
After 30 Days
Registered Trial: ChiCTR2400093739
Ovarian Health
Liver Health
Postpartum Health
Energy & Fatigue
After taking 120 mg/day of GeneIII® for 3 menstrual cycles, participants showed significant improvements in key measures linked to ovarian health.*
+38.0% ↑
+38.0% ↑
AMH
(ng/mL)
E₂
(pmol/L)
Baseline
After 3-cycle
Registered Trial: ChiCTR2500104484
Ovarian Health
Liver Health
Postpartum Health
Energy & Fatigue
In a randomized, double-blind, placebo-controlled trial, postpartum women taking 120 mg/day of GeneIII® for 30 days showed improvements in quality of life, physical fatigue, sleep, and daytime function.*
+35.9% ↑
-27.8% ↓
Quality of Life
(SF-36)
Physical Fatigue
Baseline
After 30 Days
Registered Trial: ChiCTR2500114171
3 Months
6 Months
12 Months
First 30 Days
First 30 Days
EGT starts building in your body, using a dedicated transporter to reach and stay in tissues that need it most.*
Month 3
Month 6
Month 12+
First 30 Days
3 Months
6 Months
12 Months
First 30 Days
3 Months
This is where consistency can start to feel different. Think better sleep, steadier energy, and more support for how you feel day to day.*
Month 6
Month 12+
First 30 Days
3 Months
6 Months
12 Months
First 30 Days
Month 3
6 Months
EGT accumulates in high-stress tissues like the brain, liver, eyes, and blood cells— helping protect them from the everyday wear and tear that builds with age.*
Month 12+
First 30 Days
3 Months
6 Months
12 Months
First 30 Days
Month 3
Month 6
12 Months
The real advantage is staying consistent. EGT keeps supporting your cells against everyday stress, helping you stay sharper, stronger, and more resilient over time.*
GeneIII®
L-Ergothioneine
Clinically studied to support sleep, energy, and cognitive health, with 30mg of 99.99% pure L-Ergothioneine in every capsule.*
Frequently Asked Questions
Uncompromising Quality
At GeneIII, we hold ourselves to the highest standards in research, quality, and safety.
How Benefits Build Over Time
$15M+
Invested in Clinical Studies
180K+
Customers Worldwide
100+
Peer-Reviewed Studies on EGT
30+
International Patents
Clinical Study Results
See What Sets GeneIII® Apart





- Deeper sleep*
- Natural energy*
- Mental clarity*
Subscribe & Save:
What Is GeneIII® L-Ergothioneine?
L-Ergothioneine (EGT) is a naturally occurring compound found in foods like mushrooms. Your body has a dedicated transporter called OCTN1 that actively absorbs and retains it.
Research suggests EGT accumulates in tissues exposed to high oxidative stress, including the brain and liver, where it helps support cellular health and resilience.*
GeneIII produces EGT in-house using proprietary, patented fermentation and purifies it to 99.99% purity, the highest on the market. Each capsule provides 30 mg of EGT.
Key Ingredients
L-Ergothioneine — 30 mg
Pure L-Ergothioneine produced through GeneIII’s proprietary fermentation process.
Clean formulation:
✓ Vegan
✓ Gluten-free
✓ No artificial colors
✓ No artificial sweeteners
✓ No artificial preservatives
✓ Free from dairy, shellfish, peanuts, tree nuts, and eggs
How to Take
Take 1 capsule daily, with or without food. Many people prefer taking it in the morning as part of their daily routine.
For best results, take consistently for 3 months or longer.
What to Expect
Consistency matters with L-Ergothioneine.
In GeneIII® human studies, improvements in energy, fatigue, overall wellbeing, and key measures of liver and ovarian health were seen with consistent use ranging from 30 days to several months.*
For best results, make GeneIII® part of your daily routine.
Individual results may vary.
Quality & Testing
Quality is controlled at every step, with rigorous testing to verify purity, identity, and consistency before each batch is released.
✓ Third-party lab tested
✓ Manufactured in a cGMP-compliant facility
✓ FDA GRAS Notice GRN 001270 for GeneIII® L-Ergothioneine
✓ Certificates of Analysis available
Energy & Fatigue
Liver Health
Ovarian Health
Postpartum Health
First 30 Days
3 Months
6 Months
12 Months
First 30 Days
EGT starts building in your body, using a dedicated transporter to reach and stay in tissues that need it most.*
Month 3
This is where consistency can start to feel different. Think better sleep, steadier energy, and more support for how you feel day to day.*
Month 6
EGT accumulates in high-stress tissues like the brain, liver, eyes, and blood cells— helping protect them from the everyday wear and tear that builds with age.*
Month 12
The real advantage is staying consistent. EGT keeps supporting your cells against everyday stress, helping you stay sharper, stronger, and more resilient over time.*
What is L-Ergothioneine?
L-Ergothioneine (EGT) is a rare and powerful antioxidant naturally found in mushrooms. Unlike most antioxidants, your body has a dedicated transporter called OCTN1 specifically designed to absorb and retain it in areas with high oxidative stress, including the brain, liver, eyes, and skin.
Research suggests L-Ergothioneine plays an important role in supporting cellular health, healthy aging, cognitive function, and resilience against everyday oxidative stress.
What are the benefits of L-Ergothioneine?
L-Ergothioneine helps protect cells from oxidative damage and has been studied for its role in cognitive health, sleep, energy, liver health, ovarian health, and healthy aging.* Rather than acting like a stimulant or providing an immediate boost, EGT supports cellular health over time.
Can’t I just get L-Ergothioneine from food?
You can, but typically only in very small amounts.
Certain mushrooms are among the richest natural sources, but their EGT content depends on species, growing conditions, storage, and preparation. To reach the amount found in a single GeneIII capsule, you may need to consume several hundred grams of mushrooms daily.
Supplementation provides a simple way to get a consistent, measured amount every day.
What makes GeneIII different from other L-Ergothioneine supplements?
Unlike brands that simply source L-Ergothioneine, we manufacture our own GeneIII® L-Ergothioneine, giving us greater control over purity, consistency, and quality from batch to batch. GeneIII® is rigorously tested, third-party verified, and successfully notified to the FDA as a GRAS (Generally Recognized as Safe) ingredient. Not every L-Ergothioneine ingredient on the market comes with the same level of quality control and safety evaluation.
Just as importantly, GeneIII® is the specific L-Ergothioneine used in our human clinical research—not simply generic L-Ergothioneine. So the ingredient being studied is the same ingredient you’re actually taking.
Is GeneIII® L-Ergothioneine made from mushrooms?
No. GeneIII® is made through precision fermentation, not mushroom extraction. The amount of EGT in mushrooms can vary widely, and extracting it also pulls along many other unwanted components. Fermentation gives us much tighter control over how EGT is produced, so we can deliver a consistent, highly purified 99.99% L-Ergothioneine in every batch.
Can I take GeneIII with my other supplements?
GeneIII can generally be incorporated into an existing supplement routine. If you take medications, are pregnant or breastfeeding, or have a medical condition, consult your healthcare professional before use.
How long does it take to notice benefits from L-Ergothioneine?
L-Ergothioneine isn't an instant-effect supplement, and the timeline can vary by individual. Human research has evaluated outcomes after supplementation over several weeks or longer. Some people may notice benefits within a few weeks, while others may take longer. Like many supplements, L-Ergothioneine works best when taken regularly over time.
When is the best time to take L-Ergothioneine?
L-Ergothioneine can be taken at any time of day, with or without food. Some people prefer taking it in the morning, but there is no required time. For best results, L-Ergothioneine should be taken consistently as part of a daily routine.
How much L-Ergothioneine should I take?
Each GeneIII capsule contains 30 mg of L-Ergothioneine. We recommend taking 1–2 capsules daily, or as directed by your healthcare professional.
Is GeneIII third-party tested?
Yes. GeneIII undergoes third-party laboratory testing to help verify the identity, purity, and quality of our product before it reaches you. We also maintain Certificates of Analysis for added transparency.
GeneIII vs Other EGT
Pulled directly into cells through a dedicated transporter, OCTN1
Concentrates in the brain, liver, eyes & other high-stress tissues
Crosses the blood-brain barrier
Retained in the body for weeks to months
Backed by human clinical studies
EGT vs. Other Antioxidants
EGT
Glutathione
CoQ10
Resveratrol
Partial
Partial
Unclear
Unclear
EGT vs. Other Antioxidants
GeneIII vs Other EGT
In-House Manufacturing
FDA GRAS (GRN No. 1270)
99.99% Pure EGT
30+ International Patents
Investigator-Initiated Clinical Trials
Brands
Often ≤99%


