Bio-identical hormone replacement therapy (BHRT) means that the chemical makeup of the replacement hormone is exactly the same as the human body produces. Bio-identical plant-derived estrogen and progesterone products have been safely prescribed by European physicians for over 50 years. These hormones are almost entirely without the side effects of the synthetic or semi-synthetic HRT drugs which do not allow a person to produce the full range of other hormones which are needed for the body to function at full potential.