FSH is follicle stimulating hormone is produced by the pituitary gland. High FSH levels can mean low fertility, menopause or early menopause, among other things. A prospective, interventional study published in the Journal of Clinical Endocrinology and Metabolism (2016 Jan;101(1):324-33. doi: 10.1210/jc.2015-2913. Epub 2015 Nov 2) looked at 15 obese and 12 normal-weight between the ages 28-34 years, with normal menstrual cycles. FSH was tested before and after 1 month of omega-3 PUFA supplementation with 4 g of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) daily.

Supplementation with omega-3 fatty acids resulted in reduction of FSH and FSH response to GnRH by 17% on average (P = .06 and P = .03, respectively) in non-obese woment, but not obese women. Serum levels of IL-1β and TNF-α were reduced after omega-3 PUFA supplementation in obese women, but not in non-obese women. This reduction, however, was not associated with a hormonal change in obese women. Researchers concluded that dietary administration with omega-3  fatty acids decreased serum FSH levels in non obese women but not in obese women with normal ovarian reserve.