This book is solely devoted to natural methods to increase sex drive, sexual arousal and libido, both in males and females, using natural substances, which are generally called by the name Aphrodisiac. Sexual dysfunction is extremely common among both males and females. According to World famous sex researchers, Masters and Johnson, during sexual intercourse men took around 4 minutes to reach orgasm with their partners, but women took about 10-20 minutes to reach orgasm with their partners, but only about 4 minutes to reach orgasm, when they masturbated. So it is not very difficult to guess from these figures, why anorgasmia is much more common among women than among males. Some 10% of women have never got orgasm, over 15% report difficulties of getting orgasm, and 40-50% of women have complaints about sexual dissatisfaction or becoming sexually aroused. At least 70-80% of women can get orgasm only through clitoris stimulation, but possibly at least 90% of their male partners do not known this fact or do not care about it. As is well known, clitoris stimulation is almost impossible with the most common sexual intercourse position, the Missionary position. Because women reach orgasm less often during sexual intercourse than males, they are more likely than men to have and show a fake orgasm. At least 150 million men in the World suffer from erectile dysfunction. The figure is between 10-20% in younger males but can reach over 50% at ages over 60. But premature ejaculation is much more common than erectile dysfunction. According to Masters and Johnson, up to 20% of men suffer from premature ejaculation, so they get orgasm within a very short time period during sexual intercourse and their female partner does not have any possibility of getting sexual pleasure or orgasm. Sexual dysfunction increases rapidly during aging, both among males and females, mostly due to hormonal reasons. Menopause in females decreases strongly sexual activity, due to decreasing Estrogen, DHEA and Testosterone. In males Testosterone and DHEA decrease steadily during aging, but the catabolic, "Anti-sex" hormones Cortisol and Prolactin tend to increase. There exists astonishing number of simple and very common natural products, which increase sex drive, sexual arousal, libido, erection, Testosterone, sperm count and sperm motility. This book shows over 300 plants, food items, nutrients and methods, which by research have been shown to increase sexual performance, libido, sexual arousal, Testosterone, erection, orgasm, sperm count and sperm motility, and to decrease high Cortisol and Prolactin. Together with Ethnobotanical research studies, this book shows over 600 plants and products, which are used as aphrodisiacs all over the World. This book is based strictly on scientific experiments with humans and animals, and there are totally several hundreds of research study references, which can be seen on the Reference pages at the end of the book.