Science-Based Nutrition™Environmentally FriendlyNaturally FermentedShellfish FreeDietary SupplementVeganNon-GMO/Gluten Free/Soy FreeHelps Support Joint Health Why vegan? Every year, over 7,000 tons of glucosamine derived from shellfish (primarily shrimp shells) are imported into the United States. Some shrimp are raised in water polluted with pesticides and veterinary drugs. The residue of this production is the source of significant water pollution. GreenGrown® Glucosamine's natural fermentation process uses Non-GMO corn as its source to make glucosamine. Doctor's Best Vegan. Glucosamine is an environmentally friendly and sustainable alternative to shellfish based glucosamine with the same efficacy.