Sexual Alchemy is also known as the Art of Sexual Health Preservation. It originated from Emperor Huangdi and flourished during the time of Pengzu. It is also called the “Union of Qi” technique for couples. It is a scientific practice method for sexual restraint and preservation of essence and brain energy, aiming to achieve health preservation and energy conservation through sexual intercourse. By exchanging and generating energy from the universe through sexual union between men and women, the two types of energy – yin and yang – can be exchanged within the body, fully stimulating the vitality of physiological functions and reviving weakened functions to “rise from the dead”. This leads to harmony between yin and yang, family harmony, disease prevention and longevity, and enlightenment of the mind and understanding.