The primary nutrient content of the Mangosteen is not found in its sweet inner white fruit but rather in its bitter outer hull (pericarp). Mangosteen is made purely from the active pericarp portion. Emerald Labs is formulated and clinically validated by a well-respected licensed naturopathic medical doctor (N.M.D.) according to the highest standards of his medical practice. His expertise in nutrition herbal and vitamin therapies natural hormone replacement and integrative medicine has resulted in a professional line of clinical-potency formulas directly accessible to our consumers. Emerald Labs products are: Raw Whole-Food Based Formulas for Enhanced Absorption and Bioavailability. Formulated by Dr. Mark Stengler. Therapeutic Doses with Clinical Results. 100% Additive-Free – No Magnesium Stearate. Gluten-Free Formulas. Purity Tested – cGMP Certified Facility. Every product in vegetable capsules. All Emerald Laboratories products are produced at Emerald Laboratories in our own cGMP-Certified Facility in Carson CA. Emerald Laboratories has an in-house laboratory where all raw ingredients are tested.