The seeds have a protein content of about 15%, an oil content of 24% and contain about 43% cellulose. The proteins are especially rich in the sulphur-containing amino acids methionine and cysteine, as well as in tryptophan - all essential amino acids. There is a relative deficiency in lysine and four other essential amino acids. The nutrient of greatest interest is gamma-linolenic acid (GLA), a polyunsaturated fatty acid. For this reason evening primrose oil is a widely sold dietary supplement. The whole seeds can also be used similar to sesame roasted and in pastries.