Glycitein

Glycitein at a Glance

Glycitein, or 6-methoxydaidzein, is the third major soy isoflavone, sitting behind genistein and daidzein. In the whole soybean it is the minor member of the trio — usually only about 5–10% of the total isoflavones — so most soy research treats it as a background component of the mixture rather than a target in its own right ^{17,18Reference 17Křížová L et al. · 2019IsoflavonesView study →Reference 18Zaheer K · 2017ReviewAn updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human healthView study →}.

Two things make it worth its own page. First, it is the dominant isoflavone of the soy germ (hypocotyl) — the small embryonic part of the bean — so germ-derived soy ingredients carry a far higher share of glycitein than the cotyledon-heavy whole bean ^{9Reference 9Rüfer CE et al. · 2007In vitroIn vitro and in vivo metabolism of the soy isoflavone glyciteinView study →}. Second, its single distinguishing feature — a 6-methoxy group that daidzein lacks — makes it a weaker phytoestrogen than its unmethylated relatives ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →} but appears to give it better oral absorption ^{2,4Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}.

The honest posture is the same as for the other soy isoflavones: the human clinical record (menopausal symptoms, bone) belongs to whole soy and mixed-isoflavone supplements, not to isolated glycitein, whose own data are mostly in-vitro or animal ^{19,20Reference 19Kanadys W et al. · 2021Meta-analysisEffects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trialsView study →Reference 20Wei P et al. · 2012Systematic reviewSystematic review of soy isoflavone supplements on osteoporosis in womenView study →}. It is a normal dietary constituent carried at a low toxicity flag, with the usual estrogenic-caution footnote for concentrated supplements.

Glycitein vs. Genistein & Daidzein

The defining fact about glycitein is a trade-off buried in its structure. It is daidzein with an extra methoxy (–OCH₃) group at the 6 position — hence the systematic name 6-methoxydaidzein ^{15Reference 15Lang’at-Thoruwa C et al. · 2003A simple synthesis of 7,4’-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavoneView study →}.

That one substitution pulls in two directions:

• Weaker at the estrogen receptor. In the standard assays glycitein is estrogenic but weakly so — its uterotrophic and receptor-activating potency sits in the low range of the soy isoflavones and far below genistein, the most estrogenic of the three, and far below 17β-estradiol ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →}. If you rank the trio by raw estrogen-receptor drive, glycitein is at the bottom.
• Better absorbed. The same methoxy group improves its oral bioavailability. In a controlled human study glycitein was absorbed at least as efficiently as daidzein and appeared in urine at a higher fractional rate than genistein ^{2Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →}; in a hamster feeding study its apparent absorption was significantly greater than that of the other isoflavones ^{4Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}. Its glycoside (glycitin) is efficiently hydrolysed and reaches high plasma levels with little further breakdown ^{3Reference 3Setchell KD et al. · 2001Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone supplementsView study →}.

So glycitein is the isoflavone that gives up potency for delivery. This is why it can matter out of proportion to its low receptor affinity: more of it reaches the circulation. Whether that better delivery of a weaker ligand nets out to a meaningful whole-body effect is exactly the open question the human data have not answered.

What It's Used For

Glycitein’s evidence is thin where genistein and daidzein are thick. There are no glycitein-specific human trials; the human signal is inherited from whole-soy and mixed-isoflavone studies, and the molecule’s own data are cell-culture and animal work. Read every row below with that split in mind.

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 here rests on isolated-glycitein cell/animal work or on whole-soy human data in which glycitein is only a minor component — read the per-row basis.

01Phytoestrogen — Menopausal & Bone SupportShaky40%Whole-soy/mixed-isoflavone human trials for bone/menopause ^{19,20Reference 19Kanadys W et al. · 2021Meta-analysisEffects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trialsView study →Reference 20Wei P et al. · 2012Systematic reviewSystematic review of soy isoflavone supplements on osteoporosis in womenView study →}; glycitein-specific data are receptor & bone-cell assays ^{1,11,13Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →Reference 11Gutierrez-Zepeda A et al. · 2005Soy isoflavone glycitein protects against beta amyloid-induced toxicity and oxidative stress in transgenic Caenorhabditis elegansView study →Reference 13Winzer M et al. · 2010AnimalGlycitein decreases the generation of murine osteoclasts and increases apoptosisView study →}

02Antioxidant & CytoprotectionShaky34%In-vitro ROS/JNK protection ^{6Reference 6Kang KA et al. · 2007Inhibitory effects of glycitein on hydrogen peroxide induced cell damage by scavenging reactive oxygen species and inhibiting c-Jun N-terminal kinaseView study →}, C. elegans amyloid model ^{11Reference 11Gutierrez-Zepeda A et al. · 2005Soy isoflavone glycitein protects against beta amyloid-induced toxicity and oxidative stress in transgenic Caenorhabditis elegansView study →}, one in-vivo sow feeding study ^{16Reference 16Hu YJ et al. · 2015Effect of dietary supplementation with glycitein during late pregnancy and lactation on antioxidative indices and performance of primiparous sowsView study →}

03Anticancer / AntiproliferativeShaky28%In-vitro only: breast SKBR-3 ^{5Reference 5Zhang B et al. · 2015Inhibitory effects of O-methylated isoflavone glycitein on human breast cancer SKBR-3 cellsView study →}, glioma invasion ^{10Reference 10Lee EJ et al. · 2010Glycitein inhibits glioma cell invasion through down-regulation of MMP-3 and MMP-9 gene expressionView study →}, prostate epithelial cells ^{14Reference 14Clubbs EA · 2007Glycitein activates extracellular signal-regulated kinase via vascular endothelial growth factor receptor signaling in nontumorigenic (RWPE-1) prostate epithelial cellsView study →}

04Cardiometabolic (Cholesterol)Shaky22%A single hamster feeding study (−15% total, −24% non-HDL cholesterol) ^{4Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}

Mechanisms

The load-bearing contrast is estrogenic potency vs. delivery: glycitein is the weakest ER ligand of the soy trio ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →} but the best absorbed ^{2,4Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →} — most of its plausibility rides on that trade-off rather than on receptor drive.

Pharmacokinetics

Glycitein’s kinetics are its selling point. In food it occurs mostly as the glycoside glycitin, which is hydrolysed to the aglycone in the gut; Setchell’s human work found this hydrolysis efficient, with little further biotransformation, giving high plasma glycitein concentrations ^{3Reference 3Setchell KD et al. · 2001Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone supplementsView study →}. A dedicated human study in healthy men reported absorption comparable to daidzein and a higher fractional urinary excretion than genistein, and noted that a steady plasma level is reached with several intakes across the day ^{2Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →}. Colonic bacteria then process it: Eubacterium limosum O-demethylates glycitein to 6,7,4′-trihydroxyisoflavone ^{7Reference 7Hur H · 2000Biotransformation of the isoflavonoids biochanin A, formononetin, and glycitein by Eubacterium limosumView study →}, and mixed human gut flora generate dihydroglycitein and 6-O-methyl-equol among other metabolites, with the extent of degradation varying widely between people (high/moderate/low degraders) ^{8Reference 8Simons AL et al. · 2005Metabolism of glycitein (7,4’-dihydroxy-6-methoxy-isoflavone) by human gut microfloraView study →}. In-vitro and rat metabolism also yields oxidative metabolites, with 6-hydroxy-daidzein (6-OH-DAI) the main urinary metabolite ^{9Reference 9Rüfer CE et al. · 2007In vitroIn vitro and in vivo metabolism of the soy isoflavone glyciteinView study →}. The practical read: the 6-methoxy substituent that weakens receptor binding is the same feature that improves absorption, so more glycitein reaches the circulation than its potency alone would suggest ^{4Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}.

Clinical Trials

There are no registered clinical trials of isolated glycitein. Human evidence exists only for soy foods and mixed soy-isoflavone supplements, in which glycitein is a minor component — chiefly for menopausal symptoms and bone-mineral density, where meta-analyses find modest, heterogeneous effects ^{19,20Reference 19Kanadys W et al. · 2021Meta-analysisEffects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trialsView study →Reference 20Wei P et al. · 2012Systematic reviewSystematic review of soy isoflavone supplements on osteoporosis in womenView study →}. Everything glycitein-specific is preclinical.

Last checked: July 2026.

Isolate vs. Plant Studies

Glycitein sits firmly on the isolate-in-vitro side of the ledger. The molecule’s own studies — estrogenic assays ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →}, osteoclast/osteoblast cultures ^{12,13Reference 12Yoshida H et al. · 2001Glycitein effect on suppressing the proliferation and stimulating the differentiation of osteoblastic MC3T3-E1 cellsView study →Reference 13Winzer M et al. · 2010AnimalGlycitein decreases the generation of murine osteoclasts and increases apoptosisView study →}, ROS/JNK protection ^{6Reference 6Kang KA et al. · 2007Inhibitory effects of glycitein on hydrogen peroxide induced cell damage by scavenging reactive oxygen species and inhibiting c-Jun N-terminal kinaseView study →}, the C. elegans amyloid model ^{11Reference 11Gutierrez-Zepeda A et al. · 2005Soy isoflavone glycitein protects against beta amyloid-induced toxicity and oxidative stress in transgenic Caenorhabditis elegansView study →}, the cancer cell lines ^{5,14Reference 5Zhang B et al. · 2015Inhibitory effects of O-methylated isoflavone glycitein on human breast cancer SKBR-3 cellsView study →Reference 14Clubbs EA · 2007Glycitein activates extracellular signal-regulated kinase via vascular endothelial growth factor receptor signaling in nontumorigenic (RWPE-1) prostate epithelial cellsView study →}, and the hamster cholesterol study ^{4Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →} — nearly all use purified glycitein in cells or animals, which is a clarity strength: the effects are the molecule’s, not a mixture’s. The weakness is the other half of the transferability problem: the human evidence is exclusively whole-soy / mixed-isoflavone, where glycitein is only ~5–10% of the isoflavone dose and cannot be disentangled from genistein and daidzein ^{19,20Reference 19Kanadys W et al. · 2021Meta-analysisEffects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trialsView study →Reference 20Wei P et al. · 2012Systematic reviewSystematic review of soy isoflavone supplements on osteoporosis in womenView study →}. So for glycitein we have isolate mechanism without isolate human outcomes, and human outcomes without isolate attribution — the reverse of a molecule proven in people.

Prevalence in Nature

Glycitein is, for practical purposes, a soy isoflavone. In the whole soybean (Glycine max) it is the minor member of the genistein–daidzein–glycitein trio, typically ~5–10% of total isoflavones ^{17,18Reference 17Křížová L et al. · 2019IsoflavonesView study →Reference 18Zaheer K · 2017ReviewAn updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human healthView study →}. Its distribution within the bean is uneven and this is the interesting part: it is concentrated in the germ (hypocotyl), the embryonic axis of the seed, where it becomes the dominant isoflavone rather than a trace one ^{9Reference 9Rüfer CE et al. · 2007In vitroIn vitro and in vivo metabolism of the soy isoflavone glyciteinView study →}. Because commercial “soy germ” or “soy hypocotyl” extracts are milled from that fraction, they carry a much higher glycitein share than cotyledon-based soy protein — the single most useful sourcing fact about this molecule.

Beyond soy it is reported, generally at low levels, in other legumes including red clover (Trifolium pratense) and kudzu (Pueraria spp.), whose isoflavone profiles are dominated by other members (biochanin A / formononetin in red clover; puerarin / daidzein in kudzu) ^{18Reference 18Zaheer K · 2017ReviewAn updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human healthView study →}. In plants glycitein and its relatives function as phytoalexins and nodulation signals — defence and legume–rhizobium communication molecules — which is plant biology, not a prediction of human pharmacology.

Discovery & Synthesis

Glycitein was characterised as the third soybean isoflavone alongside genistein and daidzein, its structure established as 7,4′-dihydroxy-6-methoxyisoflavone — daidzein bearing an extra 6-methoxy group ^{15Reference 15Lang’at-Thoruwa C et al. · 2003A simple synthesis of 7,4’-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavoneView study →}. As a laboratory target it long trailed its more famous relatives; a simple total synthesis was published in 2003 by Lang’at-Thoruwa and colleagues, who built the isoflavone skeleton and installed the 6-methoxy substituent to obtain glycitein directly, explicitly to make “the third soybean isoflavone” available for study ^{15Reference 15Lang’at-Thoruwa C et al. · 2003A simple synthesis of 7,4’-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavoneView study →}. Manufacture today is overwhelmingly by extraction and enrichment from soy, particularly the glycitein-rich germ/hypocotyl fraction, rather than by total synthesis; the molecule is a food-derived constituent, not a bulk synthetic chemical.

Patents: not yet researched.

Toxicity & Safety

Glycitein carries a low toxicity flag. It is a normal dietary constituent of soy foods eaten safely for centuries, present in ordinary meals at levels far below anything studied for harm, and no distinct toxicity syndrome is attributed to it ^{17,18Reference 17Křížová L et al. · 2019IsoflavonesView study →Reference 18Zaheer K · 2017ReviewAn updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human healthView study →}. The single genuine caveat is shared by the whole soy-isoflavone class rather than specific to glycitein: it is a phytoestrogen, so the relevant caution is about concentrated isoflavone supplements in hormone-sensitive situations, not dietary soy. Glycitein is the weakest estrogen of the three major soy isoflavones ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →}, which makes its individual estrogenic risk correspondingly small — but its better absorption means more of it circulates ^{2,4Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}, so it is not simply negligible.

Safety at a Glance

✅ Low / no toxicity

• Ordinary dietary constituent. Glycitein is a minor, long-consumed component of soy foods with no distinct toxicity attributed to it.
• Weakest of the soy phytoestrogens. Its estrogen-receptor activity is well below genistein and daidzein ^{1Reference 1Song TT et al. · 1999Estrogenic activity of glycitein, a soy isoflavoneView study →}.
• Phytoestrogen — concentrated supplements. As with all soy isoflavones, caution is advised for hormone-sensitive situations when taking concentrated isoflavone / soy-germ supplements, not for dietary soy.
• Better absorbed than its potency suggests. The 6-methoxy group raises glycitein’s bioavailability, so estrogenic exposure per milligram is not as trivial as its weak receptor binding implies ^{2,4Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}.

Reproductive/developmental toxicity for isolated glycitein has not been characterised; pregnancy and lactation decisions belong to the soy food or supplement product where intake is decided, not to this molecule page. No comprehensive isolate genotoxicity or repeat-dose package is characterised here beyond the dietary and phytoestrogen-class context above.

Dosage

There is no established dose of isolated glycitein, and it is not sold as a stand-alone supplement. Human exposure is dietary, as part of the soy isoflavone mixture, or via soy-germ / hypocotyl extracts, which are unusually glycitein-rich ^{9Reference 9Rüfer CE et al. · 2007In vitroIn vitro and in vivo metabolism of the soy isoflavone glyciteinView study →}. In soy isoflavone research the total isoflavone dose typically runs ~40–100 mg/day, of which glycitein is only a small fraction (roughly 5–10% in whole-bean material, more in germ-derived products) ^{18,19Reference 18Zaheer K · 2017ReviewAn updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human healthView study →Reference 19Kanadys W et al. · 2021Meta-analysisEffects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trialsView study →}. Because glycitein is comparatively well absorbed ^{2,4Reference 2Shinkaruk S et al. · 2012Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian menView study →Reference 4Lee SO et al. · 2007Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamstersView study →}, a germ-based supplement can deliver more circulating glycitein than the raw milligram figure implies. These are the figures used in research on the soy isoflavone mixture and are not a personal recommendation.

References

1. Song TT, Hendrich S, Murphy PA (1999). Estrogenic activity of glycitein, a soy isoflavone. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/10564025/
2. Shinkaruk S, et al. (2012). Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian men. Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/22953831/
3. Setchell KD, et al. (2001). Bioavailability of pure isoflavones in healthy humans and analysis of commercial soy isoflavone supplements. Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/11285356/
4. Lee SO, Renouf M, Ye Z, Murphy PA, Hendrich S (2007). Isoflavone glycitein diminished plasma cholesterol in female golden Syrian hamsters. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/18038972/
5. Zhang B, et al. (2015). Inhibitory effects of O-methylated isoflavone glycitein on human breast cancer SKBR-3 cells. International Journal of Clinical and Experimental Pathology. https://pubmed.ncbi.nlm.nih.gov/26339345/
6. Kang KA, et al. (2007). Inhibitory effects of glycitein on hydrogen peroxide induced cell damage by scavenging reactive oxygen species and inhibiting c-Jun N-terminal kinase. Free Radical Research. https://pubmed.ncbi.nlm.nih.gov/17516245/
7. Hur H, Rafii F (2000). Biotransformation of the isoflavonoids biochanin A, formononetin, and glycitein by Eubacterium limosum. FEMS Microbiology Letters. https://pubmed.ncbi.nlm.nih.gov/11040423/
8. Simons AL, Renouf M, Hendrich S, Murphy PA (2005). Metabolism of glycitein (7,4’-dihydroxy-6-methoxy-isoflavone) by human gut microflora. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/16248547/
9. Rüfer CE, Maul R, Donauer E, Fabian EJ, Kulling SE (2007). In vitro and in vivo metabolism of the soy isoflavone glycitein. Molecular Nutrition & Food Research. https://pubmed.ncbi.nlm.nih.gov/17579888/
10. Lee EJ, et al. (2010). Glycitein inhibits glioma cell invasion through down-regulation of MMP-3 and MMP-9 gene expression. Chemico-Biological Interactions. https://pubmed.ncbi.nlm.nih.gov/20188714/
11. Gutierrez-Zepeda A, et al. (2005). Soy isoflavone glycitein protects against beta amyloid-induced toxicity and oxidative stress in transgenic Caenorhabditis elegans. BMC Neuroscience. https://pubmed.ncbi.nlm.nih.gov/16122394/
12. Yoshida H, et al. (2001). Glycitein effect on suppressing the proliferation and stimulating the differentiation of osteoblastic MC3T3-E1 cells. Bioscience, Biotechnology, and Biochemistry. https://pubmed.ncbi.nlm.nih.gov/11440142/
13. Winzer M, et al. (2010). Glycitein decreases the generation of murine osteoclasts and increases apoptosis. Wiener Medizinische Wochenschrift. https://pubmed.ncbi.nlm.nih.gov/20714813/
14. Clubbs EA, Bomser JA (2007). Glycitein activates extracellular signal-regulated kinase via vascular endothelial growth factor receptor signaling in nontumorigenic (RWPE-1) prostate epithelial cells. Journal of Nutritional Biochemistry. https://pubmed.ncbi.nlm.nih.gov/17156992/
15. Lang’at-Thoruwa C, Song TT, Hu J, Simons AL, Murphy PA (2003). A simple synthesis of 7,4’-dihydroxy-6-methoxyisoflavone, glycitein, the third soybean isoflavone. Journal of Natural Products. https://pubmed.ncbi.nlm.nih.gov/12542367/
16. Hu YJ, et al. (2015). Effect of dietary supplementation with glycitein during late pregnancy and lactation on antioxidative indices and performance of primiparous sows. Journal of Animal Science. https://pubmed.ncbi.nlm.nih.gov/26020321/
17. Křížová L, Dadáková K, Kašparovská J, Kašparovský T (2019). Isoflavones. Molecules. https://pubmed.ncbi.nlm.nih.gov/30893792/
18. Zaheer K, Humayoun Akhtar M (2017). An updated review of dietary isoflavones: nutrition, processing, bioavailability and impacts on human health. Critical Reviews in Food Science and Nutrition. https://pubmed.ncbi.nlm.nih.gov/26565435/
19. Kanadys W, et al. (2021). Effects of soy isoflavones on biochemical markers of bone metabolism in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials. International Journal of Environmental Research and Public Health. https://pubmed.ncbi.nlm.nih.gov/34067865/
20. Wei P, Liu M, Chen Y, Chen DC (2012). Systematic review of soy isoflavone supplements on osteoporosis in women. Asian Pacific Journal of Tropical Medicine. https://pubmed.ncbi.nlm.nih.gov/22305793/

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