Bremelanotide. It's a nasal spray, works quickly. Looks like it can be bought online.
Is it a party drug, or a medical drug? I do not know. Haven't tried it yet, personally, but I probably would if only for my educational purposes...
All of the late middle-aged docs I know are "scientifically" curious about it. It is said to be the only true aphrodisiac. If it has no serious side effects, I can see this drug leave Oxycontin in the dust on the black market.
Not everybody, for sure, is fully satisfied with his or her sex life, unless young and in love.