Estro Clear is calcium bound to d-glucaric acid, which is a natural compound produced in small amounts by the human body and is abundantly found in various plant foods such as broccoli, cabbage, kale, apples, oranges, and grapefruit. Research shows that d-glucaric acid derivatives such as calcium d-glucarate help support the body’s natural defense against toxins and excess steroid hormones.** Unlike glucaric acid, Estro Clear is available as a supplement. Oral supplementation of Estro Clear is an ideal way to provide the body with an efficient, slow-release source of its active metabolite, D-glucaro-1, 4-lactone.