Libido is a sexual desire or drive. Libido is biological desire’s emotional energy, especially sexual desire. Biopsychosocial variables affect libido. Biologically, sex hormones and nucleus accumbent neurotransmitters (mainly testosterone and dopamine) govern human desire. Working, family, mentality, and stress might affect libido. Medical disorders, drugs, lifestyle, relationships, and age might affect libido (e.g., puberty). Hypersexuality is having frequent or suddenly increased sexual impulses; hyposexuality is the opposite. In psychoanalytic thought, libido is a mental drive or energy, connected with sexual instinct but is also present in other innate urges. A man may want sex but not be able to act on it, or may not for medical, moral, or religious reasons. Repressing or sublimating an urge is psychological. One can participate in sexual activity without a sire. Stress, illness, and pregnancy affect sperm drive. Testosterone, estrogen, progesterone, oxytocin, and norepinephrine act as serotonin This book chapter talks about how functional foods such as spinach, dark chocolate, peppers, green tea, oysters, crab, and pumpkin seeds, which contain neurotransmitters, affect libido.