A surefire way to get into a woman's pants is Rohypnol, otherwise known as "roofies", "ruffies", "roche", "R-2", "rib", and "rope".
Rohypnol is a brand name for flunitrazepam, a very potent tranquilizer similar in nature to valium but many times stronger. The drug produces a sedative effect, amnesia, muscle relaxation, and a slowing of psychomotor responses. Sedation occurs 20-30 minutes after administration and lasts for several hours. Rohypnol can be combined with alcohol, marijuana, or cocaine to produce a very rapid high, or it can be added to any kind of drink and given to females in hopes of lowered inhibitions and facilitating potential sexual conquest.
An amnesia producing effect of Rohypnol may prevent users from remembering how or why they took the drug or even that they were given it by others. This makes investigation of sexually related or other offenses very difficult and may account for repeated reports of "date rapes" involving the use of the drug.
This is purely informational and I strongly advise you against using Rohypnol to get laid, even if you're such a loser you can't get laid otherwise. Thank you.