What it is
Seed oils sold in capsules for their GLA — taken for skin, inflammation and PMS on the strength of one fatty acid.
Why your biology objects
The GLA story is the marketing; structurally these are among the highest omega-6 oils made — evening primrose runs ~70% linoleic acid — a massive peroxidation substrate with no ancestral precedent at supplement doses. The benefit claim doesn't offset the absolute LA load.