Dr. Riegel saw a need to serve women in the realms of Sexual Dysfunction, Menopause and Age Management Medicine. As these areas are not addressed in formal Ob/Gyn training, Dr. Riegel sought out the leading experts internationally for their knowledge. He underwent years of additional course work and training in these areas from The Berman Center, The Cenegenics Medical Institute and the American College of Ob/Gyn. In 2005, Dr. Riegel opened the first specialty clinic of it's kind in North Texas, The Center for Female Sexual Medicine and Menopause.

The Center has served thousands of women from all over Texas. The word is out and women have been telling their friends. Dr. Riegel sees many new patients everyday at the urging of their friends and family. Patients have travelled from as far as Alabama and Arizona for the treatments Dr. Riegel has tailored specifically for them. With a regimen of diet, exercise, vitamins, antioxidants and hormone replacement therapy, Dr. Riegel is able to transform the condition of women to enable them to lead healthier and more productive lives. Many paients have expressed their gratitude and amazement to Dr. Riegel in saying "I haven't felt this good in 15 years" and "What can I say? Thanks for giving me my life back." For Dr. Riegel, there is nothing more rewarding than helping a patient transform her life through his treatment regimens.