other · for hot flashes
Evening Primrose Oil
Its active fat is thought to act on the signals that widen blood vessels during a flush.
Say that in clinical terms
Gamma-linolenic acid (GLA), the active fatty acid in evening primrose oil, is thought to influence prostaglandin pathways involved in blood vessel dilation, but a specific hot-flash mechanism has not been established.
How strong is the research?
No Benefit evidence
The Menopause Society does not recommend herbal supplements for hot flushes.
Clinical guideline
3 papers read, 2 against.
Tested as: evening primrose oil capsules, 500 mg twice daily (1,000 mg/day total) in the most-cited RCT; other trials in the meta-analysis used comparable gram-level daily doses.
Who was studied: Studied in postmenopausal women aged 45 to 59 with troublesome hot flushes.
How much to take
500–1000 mg