They are called aphrodisiac substances.
An aphrodisiac is any substance that is supposed to fuel sexual desire and arousal. The term comes from Aphrodite (goddess of germination, love, pleasures, and beauty in Greek mythology).
These products are supposed to stimulate the libido, to favor the intensity of the orgasm, to facilitate the erection of the men, or to increase the sexual performances.
For example, ginger is known to be a good aphrodisiac for men. Certain drug improves the sexual performance like Sildenafil (VIAGRA)