An orally available capsule-based nutritional supplement containing indole-3-carbinol, calcium-D-glucarate, Schizandra, vitamin D3, milk thistle, stinging nettle and hydroxymatairesinol (HMR) lignans, with potential estrogen modulating, antiproliferative and antioxidant activity. Indole-3-carbinol, found in vegetables of the Cruciferae family, may inhibit mammary cell growth and exerts antiestrogenic activity; Milk thistle (Silybum marianum) and Schizandra chinensis may enhance some of the phase II detoxification enzymes; calcium-D-glucarate and vitamin D3 may inhibit mammary cell growth; stinging nettle may exert its effect through its aromatase inhibiting activity; HMR lignans may have a beneficial effect on estrogen balance and levels. Therefore, ingredients in indole-3-carbinol/calcium/Schizandra/vitamin D3/milk thistle/stinging nettle/lignan-based nutritional capsule may alter estrogen balance and may protect against mammary carcinogenesis.