The lignans contained in flaxseed are phytoestrogens that can exert weak estrogenic effects and also antiestrogenic effects when binding to estrogen receptors. However, there is no clear research on the effect that flaxseed could have on sex hormones like testosterone or estrogen. A meta-analysis from 2023 found that flaxseed supplementation had no effect on testosterone, sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH), and dehydroepiandrosterone (DHEA).[1] However, some concerns still exist regarding flaxseed supplementation during pregnancy and whether it could affect male fertility.[2][1]
Can flaxseed affect sex hormones?
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•Last Updated: May 16, 2025
Flaxseed contains lignans that can have weak estrogenic and antiestrogenic effects, but research shows that it does not significantly affect sex hormones like testosterone, SHBG, FSH, or DHEA. There are still concerns about its effects during pregnancy and potential effects on male fertility.