# Secoisolariciresinol diglucoside **Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/secoisolariciresinol-diglucoside **Data Source:** Hermetica Superfoods Ingredient Encyclopedia **Updated:** 2026-03-30 **Evidence Score:** 2 / 10 **Category:** Compound **Also Known As:** SDG, Secoisolariciresinol di-glucoside, Flaxseed lignan, Linum usitatissimum lignan, Plant lignan diglucoside, Phytoestrogen lignan, Enterolactone precursor ## Overview Secoisolariciresinol diglucoside (SDG) is a plant lignan found primarily in flaxseed that acts as a precursor to the mammalian lignans enterodiol and enterolactone. These metabolites exhibit phytoestrogenic activity and provide [antioxidant protection](/ingredients/condition/antioxidant) against oxidative stress and liver peroxidation damage. ## Health Benefits • Antihyperglycemic effects: SDG at 25 mg/kg body weight showed potential in animal models [1]. • [Antioxidant](/ingredients/condition/antioxidant) properties: Functions as a phytoestrogen preventing liver peroxidation damage [1]. • Precursor to mammalian lignans: Converts to enterodiol and enterolactone in the colon, which have health benefits [7]. • Potential [cardiovascular](/ingredients/condition/heart-health) benefits: Derived from its antioxidant capacity, though specific human studies are lacking [4]. • Supports [hormonal balance](/ingredients/condition/hormonal): As a phytoestrogen, may help modulate estrogen levels, though direct evidence is minimal [4]. ## Mechanism of Action SDG is converted by colonic bacteria into the mammalian lignans enterodiol and enterolactone, which bind to estrogen receptors and exert phytoestrogenic effects. These metabolites scavenge free radicals and inhibit [lipid peroxidation](/ingredients/condition/antioxidant) through their phenolic hydroxyl groups. The compounds also modulate [glucose metabolism](/ingredients/condition/weight-management) pathways, contributing to their antihyperglycemic properties. ## Clinical Summary Current evidence for SDG comes primarily from animal studies rather than human clinical trials. In animal models, SDG at 25 mg/kg body weight demonstrated antihyperglycemic effects and liver protection against oxidative damage. The compound's conversion to enterodiol and enterolactone has been documented in human studies, though specific health outcomes from SDG supplementation require more extensive clinical research. Evidence strength remains preliminary due to limited human trials. ## Nutritional Profile Secoisolariciresinol diglucoside (SDG) is a pure polyphenolic lignan compound, not a whole food, so traditional macronutrient/micronutrient profiles do not apply. Key compositional and bioactive data: SDG is a diglucoside ester of secoisolariciresinol (SECO), with molecular weight approximately 686.7 g/mol. It is the predominant lignan in flaxseed, found at concentrations of 6–37 mg/g of defatted flaxseed meal, and is typically isolated as part of a lignan-rich fraction (SDG complex) comprising approximately 40–60% SDG by weight alongside other phenolic compounds including cinnamic acid glucosides (ferulic acid glucoside, p-coumaric acid glucoside) and 3-hydroxy-3-methyl glutaric acid. As an isolated compound, it contains no meaningful protein, fat, or carbohydrate nutritional content. Bioactive profile: SDG serves as a direct precursor to mammalian lignans enterodiol (ED) and enterolactone (EL) via colonic bacterial [metabolism](/ingredients/condition/weight-management); conversion efficiency varies by [gut microbiome](/ingredients/condition/gut-health) composition. SDG itself exhibits [antioxidant activity](/ingredients/condition/antioxidant) with an oxygen radical absorbance capacity (ORAC) measurable in vitro. Bioavailability: oral bioavailability of SDG is moderate; colonic bacteria cleave the glucoside bonds releasing SECO, which is further converted to ED and EL. Peak plasma enterolactone levels typically appear 8–10 hours post-ingestion. Fat co-ingestion may enhance absorption. Typical experimental doses used in animal studies: 25 mg/kg body weight. Human supplementation studies have used SDG complex doses of 300–600 mg/day. ## Dosage & Preparation Animal studies suggest an effective dose of 25 mg/kg body weight for antihyperglycemic effects. Human dosage guidelines are not available from the provided research. Consult a healthcare provider before starting any new supplement. ## Safety & Drug Interactions SDG safety profile appears favorable based on its natural occurrence in flaxseed, though comprehensive safety data is limited. Due to its phytoestrogenic activity through enterodiol and enterolactone metabolites, individuals with hormone-sensitive conditions should exercise caution. Potential interactions with anticoagulant medications may occur due to flaxseed's fiber content affecting drug absorption. Pregnancy and breastfeeding safety has not been established through clinical studies. ## Scientific Research The research dossier does not provide specific human clinical trials or meta-analyses with PubMed PMIDs. The references to antihyperglycemic effects and the role of SDG as a precursor to mammalian lignans are based on preliminary findings from animal studies and biochemical analyses. ## Historical & Cultural Context The research dossier does not include information on the traditional or historical use of SDG. Its applications seem to be more contemporary, focusing on its biochemical properties and potential health benefits. ## Synergistic Combinations Flaxseed oil, Omega-3 fatty acids, Vitamin E, Curcumin, Resveratrol ## Frequently Asked Questions ### What foods contain secoisolariciresinol diglucoside? Flaxseed is the richest dietary source of SDG, containing 75-800 mg per 100g depending on variety. Smaller amounts are found in sesame seeds, sunflower seeds, and some whole grains like rye and oats. ### How much secoisolariciresinol diglucoside is in flaxseed? Flaxseed contains approximately 75-800 mg of SDG per 100g, with brown flaxseed typically containing higher concentrations than golden varieties. One tablespoon of ground flaxseed provides roughly 8-85 mg of SDG. ### Does cooking destroy secoisolariciresinol diglucoside? SDG is relatively heat-stable, with studies showing minimal degradation during normal cooking temperatures. However, extensive processing and high-temperature treatments may reduce SDG content by 10-30%. ### How long does it take for SDG to convert to lignans? Bacterial conversion of SDG to enterodiol and enterolactone typically occurs within 8-24 hours in the colon. Peak plasma levels of these mammalian lignans are usually reached 15-20 hours after flaxseed consumption. ### Can secoisolariciresinol diglucoside help with diabetes? Animal studies suggest SDG at 25 mg/kg body weight may have antihyperglycemic effects, but human clinical trials are lacking. Current evidence is too preliminary to recommend SDG specifically for diabetes management. ### What is the difference between secoisolariciresinol diglucoside (SDG) and the lignans it converts to? Secoisolariciresinol diglucoside (SDG) is a plant lignan precursor found in foods like flaxseed, while enterodiol and enterolactone are mammalian lignans produced when gut bacteria convert SDG in the colon. SDG itself has limited bioactivity until this microbial conversion occurs, making the end-product lignans responsible for most health benefits including antioxidant and phytoestrogenic effects. Individual variation in gut microbiota affects how efficiently SDG is converted, which influences the actual bioavailable lignans your body receives. ### Does SDG supplementation require a healthy gut microbiome to be effective? Yes, secoisolariciresinol diglucoside requires adequate gut bacteria to convert into active mammalian lignans (enterodiol and enterolactone), making microbiome health critical for its therapeutic potential. People with dysbiosis, those taking long-term antibiotics, or those with certain digestive conditions may have reduced lignan conversion and thus diminished health benefits from SDG. Maintaining a diverse, healthy gut microbiota through diet and lifestyle may optimize SDG's antioxidant and cardiovascular benefits. ### Is secoisolariciresinol diglucoside safe to combine with hormone-sensitive medications or hormone replacement therapy? Because SDG functions as a phytoestrogen and converts to estrogenic mammalian lignans, people taking hormone-sensitive medications or hormone replacement therapy should consult their healthcare provider before supplementing. While SDG's estrogenic activity is generally mild compared to pharmaceutical hormones, cumulative effects could theoretically interfere with hormone-related treatments or conditions. Individual risk depends on dosage, baseline estrogen levels, and specific medications involved. --- *Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com* *License: CC BY-NC-SA 4.0 — Attribution required. Commercial use: admin@hermeticasuperfoods.com*