GLA - Gama Linolenic Acid was first isolated from Evening Primrose oil.  Even better sources are  Borage Oil, and Black Currant Oil

If the body is healthy, it should be able to convert linoleic acid better known as Omega 6 oil into GLA.

Most diets already contain an ample supply of Omega 6. It is important to take Omega 3 oils when consuming isolated GLA, because the body might convert GLA into bad eicosanoids unless there is an adequate amount of EPA from the Omega 3.

These eicosandoids can contribute to inflammation, high blood pressure and lowered immune response.

However GLA with EPA helps reduce inflammation, and nerve pain in those who have neuropathy..  It is also shows promise as a vessel dilator, anti coagulant, PMS, arthritis, cardiac disease and retaining young looking skin.

A study on estrogen effected breast cancer show that woman taking GLA responded better when taking tamoxifen.