, high strength gla 12%, stronger than straight evening primrose oil, vegetarian capsules with vitamin e at 83% nrv, pharmaceutical gmp standardswe’ve made this one of the strongest evening primrose oil product available in the uk by blending it with pure starflower oil to raise the gla to 12% (most evening primrose products contain between 8-10% gla). this makes the product great value for your money as it is considerably cheaper than most straight evening primrose products available in the shops.gla is an omega 6 fatty acid which can be made by the body but several studies have shown that a supplement is useful for some people. evening primrose oil is still one of the most popular supplements a status that is achieved by the simple fact that users find it makes a real difference.our other gla products are shown below with the strongest being the pure starflower oil product.