🦴🦴🦴 Did you know 1 in 2 women in the United States over the age of 50 will have an osteoporosis-related fracture in her lifetime? During perimenopause, which can be as little as two or as many as eight years before the end of menstrual cycles, estrogen levels start to decrease. Between the ages of thirty and 35, your body will lose more bone mass than it can replace. That means women ages 35 and older should be particularly conscientious about maintaining strong, healthy bones.