Douglas Laboratories. Skin And Bone Health: Vitamin C is essential for the synthesis of collagen and glycosaminoglycans, which are the building materials of all connective tissues, such as skin, blood vessels, tendons, joint cartilage and bone. Immune Support: L-Lysine has been shown to be effective in supporting the healthy immune system.* Bone & Joint: Our bone & joint formulas are developed to help maintain healthy mobility and active lifestyles into the later years of adulthood.* Our uncompromising operational practices at our state-of-the-art manufacturing facilities surpass GMP standards and manufacturing regulations. All of our products are GMO-free. For 65 years, Douglas Laboratories has been dedicated to meeting the needs of healthcare professionals. As a globally recognized leader in the development of innovative, science-based nutritional supplements, we strive to help healthcare professionals and their patients push their potential for healthy living, today and in the future.*