What Low L-Ergothioneine Levels May Mean for Women's Health

Jul 7, 2026 GeneIII Admin

The human body cannot make L-ergothioneine on its own; its entire reserve comes from diet. As intake of ergothioneine-rich foods like mushrooms falls short, blood levels tend to decline — and this "ergothioneine gap" is increasingly being linked to women's health concerns.

Research by Professor Barry Halliwell's team at the National University of Singapore has observed that people with lower L-ergothioneine levels tend to fare worse across several health measures. That makes maintaining adequate L-ergothioneine levels a new angle worth attention in women's health.

Why L-Ergothioneine Is an Essential Nutrient

L-ergothioneine is a naturally occurring sulfur-containing amino acid, first isolated from ergot fungus in 1909 and later found in mushrooms, black beans, and other foods.

What sets it apart is the body's active uptake mechanism: a transporter called OCTN1, specifically expressed on cell membranes, efficiently absorbs L-ergothioneine from the diet and concentrates it selectively in tissues under the highest oxidative stress — the liver, kidneys, red blood cells, eyes, and reproductive cells such as sperm and oocytes.

The fact that the body maintains a dedicated transporter for a single nutrient speaks to its physiological importance. The key point is that the body cannot synthesize it; its supply comes entirely from diet. When intake of ergothioneine-rich foods is low, blood levels fall accordingly. For why everyday diet often falls short, see Why Diet Alone Isn't Enough for Sufficient L-Ergothioneine.

How L-Ergothioneine Levels Relate to Health Risks

A series of studies led by Professor Halliwell at the National University of Singapore has begun to reveal a potential relationship between blood L-ergothioneine levels and health status.

The research observed that people with lower L-ergothioneine levels face a higher risk of age-related neurological conditions such as dementia, as well as a higher risk of eye conditions like macular degeneration.

In women's health, a study led by Professor Douglas Kell in the UK found that lower L-ergothioneine levels were associated with an increased risk of preeclampsia in pregnancy, while women with higher levels were considerably less likely to develop this complication.

It is worth noting that these are associations observed at the epidemiological level and are not the same as causal conclusions. Still, they point in a common direction: an adequate L-ergothioneine level may be a meaningful baseline condition for maintaining health.

On the strength of these findings, Professor Halliwell has proposed that dietary L-ergothioneine is an important nutrient for sustaining normal physiological function.

Why Women in Particular Should Pay Attention

There are specific reasons for women to take note. OCTN1 concentrates L-ergothioneine in reproductive cells such as oocytes, and research has observed that women with declining ovarian function or infertility may have lower L-ergothioneine levels than those with normal fertility.

Pregnancy is a telling case. The oxidative stress burden on the mother's body is markedly higher during pregnancy, which gives cell-protective antioxidant nutrients particular significance at this stage.

Research has also found that L-ergothioneine can cross the placenta to the fetus — the higher the mother's level, the higher the level in the infant. From fertility through pregnancy to overall health, L-ergothioneine spans multiple life stages; for the fuller view, see L-Ergothioneine Across Women's Health Stages.

How to Maintain Adequate L-Ergothioneine Levels

Since the body depends on diet for L-ergothioneine and diet often falls short, steady supplementation becomes a practical way to maintain levels.

GeneIII has carried out several registered human clinical studies focused on women's health. In one study on ovarian reserve (ChiCTR2500104484), participants showed an average 36.26% increase in AMH, an indicator of ovarian function, after supplementing with L-ergothioneine.

This offers one indication that relevant health markers may improve when L-ergothioneine levels are restored. For the full picture, see GeneIII's 8 Clinical Trials.

On the product side, GeneIII's L-ergothioneine is produced through whole-cell fermentation, with third-party HPLC analysis reaching 99.99% purity, and has successfully filed for GRAS status with the FDA under GRN 001270. To view the product directly, visit the GeneIII L-Ergothioneine capsules product page.

FAQ: L-Ergothioneine and Women's Health

Q1: What happens if L-ergothioneine levels are low?

Research has observed that people with lower L-ergothioneine levels face relatively higher health risks in neurological, eye, and pregnancy-related areas. These are associations, suggesting that maintaining adequate levels is worthwhile.

Q2: Why should women pay particular attention to L-ergothioneine?

It is concentrated in reproductive cells such as oocytes and can cross the placenta to the fetus; the higher oxidative stress of pregnancy gives it significance across women's life stages.

Q3: Can L-ergothioneine levels be restored?

Yes. Because the body obtains L-ergothioneine from diet, steady supplementation is an effective way to maintain levels when dietary intake is insufficient.

Q4: Can it be taken during pregnancy or breastfeeding?

EFSA's safety assessment confirmed synthetic L-ergothioneine is safe for all population groups, including pregnant and breastfeeding women. Consult your doctor regarding your individual health situation.

Q5: Where can these studies be found?

These studies are registered with the Chinese Clinical Trial Registry (ChiCTR, chictr.org.cn) and are also searchable through the WHO International Clinical Trials Registry Platform (ICTRP, trialsearch.who.int) using their registration numbers.