Certified Organic 1000 mg Double Strength   Spirulina is a blue-green microalgae that has naturally occurring protein plus other nutrients such as vitamins, minerals and GLA (gamma-linolenic acid). NOW Spirulina delivers the natural nutrient profile found in genuine whole foods. This double strength product has twice the spirulina (1,000 mg per tablet) as in our regular strength product (500 mg per tablet).