Flaxseed (Linum usitatissimum) is used to support the female reproductive system based on both traditional use and emerging scientific evidence. Flaxseed is a rich source of lignans, which are phytoestrogens—plant compounds that have a weak estrogenic effect in the body. These phytoestrogens are thought to modulate estrogen metabolism, which may be beneficial for hormone balance in women.

Scientific studies have investigated flaxseed for its potential effects on menstrual health, menopausal symptoms, and hormonal regulation. Some small clinical trials and observational studies suggest that flaxseed supplementation may decrease the severity of hot flashes and improve menstrual regularity by influencing estrogen levels. For example, a few studies have found that daily flaxseed consumption modestly reduced hot flash frequency and intensity in menopausal women. Other research indicates that flaxseed may help to regulate menstrual cycle length and ovulation in women with irregular cycles, potentially due to its lignan content.

However, the overall quality and quantity of scientific evidence is moderate, with some inconsistencies in findings and many studies being small or preliminary. Major health organizations do not currently recognize flaxseed as a primary treatment for reproductive system concerns, but it is considered safe as a dietary supplement. In summary, there is some scientific support for the use of flaxseed for female reproductive health, especially for mild menopausal symptoms, but more large-scale, high-quality studies are needed.