Evidence supporting the use of: Evening primrose oil
For the health condition: Menstrual Irregularity

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Synopsis

Source of validity: Traditional
Rating (out of 5): 1

Evening primrose oil (EPO) has traditionally been used as a natural remedy to support menstrual health and to address menstrual irregularities such as irregular cycles, premenstrual syndrome (PMS), and associated symptoms like breast tenderness and mood swings. Historical and folk medicine sources have described its use for women's health, attributing its benefits to the gamma-linolenic acid (GLA) content, an omega-6 fatty acid thought to modulate prostaglandin synthesis and thereby influence hormonal balance and inflammation.

However, the scientific evidence supporting the use of EPO specifically for menstrual irregularity is limited and weak. Most studies and reviews focus on EPO’s effects on PMS or mastalgia (breast pain) rather than on cycle regularity itself. The available clinical trials are often small, methodologically limited, and have yielded inconsistent results. Some women report subjective improvement in menstrual symptoms, but these outcomes may be influenced by placebo effects or are not directly related to restoring regular menstrual cycles.

Major health organizations and systematic reviews generally conclude that robust scientific evidence is lacking to recommend evening primrose oil for menstrual irregularity. Its continued use for this purpose is primarily based on traditional practice and anecdotal reports, rather than large, high-quality scientific studies.

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