Serene Science Theanine Serene with Magnesium from Source Naturals features the amino acids L-theanine and taurine to promote brain wave activity and ease tension, plus the calming neurotransmitter GABA, magnesium and holy basil for added support. Suitable for vegetarians. Contains no yeast, dairy, egg, gluten, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.