[The best known is Cannabis.  The other is small doses of LSD.  Pleasure increases as you go up the States/Levels of consciousness Eight Circuits of Consciousness. Better still, learn Tantra and combine the two.  Avoid Amphetamines and Cocaine.]

8 Basic Winner and Loser scripts by Robert Anton Wilson

See: Psychedelics  Impotence

[2017 June] I Tried "Weed Lube" and Oh My God, Yes

[2016]  Is Cannabis An Aphrodisiac?

[1998] Marijuana and Sex: A Classic Combination

Much of the alchemical literature of Europe now appears to be a coded tradition of drug-and-sex programming.
....This code is especially notable in The Chemical Marriage of Christian Rosycross (1615), which forms the visible link between traditional alchemy and modern Rosicrucianism. The mystical rose and cross from which the Rosicrurians take their name are, in fact, no more or less than the vagina and the penis, respectively...(For the curious, here is the rest of the traditional symbolism, as given by Louis T. Culling in his Manual of Sex Magich Cucurbit—the vagina; retort—the same, during copulation; eagle—the vagina, or the female mouth, depending on the context; lion—the penis; transmutation—the sexual "peak experience"; elixer of life—the semen; quintessence—the semen as transmuted by ritual and ecstasy.) ----Sex and Drugs by Robert Anton Wilson p66

'LSD for sure; for me at least. The lady and I went camping on two and a half tabs (we split a 5 strip) and ended up cuddling on a flat rock after setting up camp. Nothing was said, we both got up, went to the tent and started to dry hump and kissing each other. Made crazy cosmic love and smoked bowls for about 4 hours inside our tent. It was one of the craziest experiences I have ever had. I felt like I had broken through. My only complaint is that it makes climaxing difficult but not impossible, things just get distracting. It feels crazy as hell and i'd recommend it 100% to anyone who enjoys LSD and the sexytime. She got way more playful than usual, and played with me and really got into what turns me on. A very connecting experience. Increased my visuals most definitely as well, her dreads were turning into roots and massaging me while everything had a bright patterned overtone and kept her in the center of my attention. She said that she wasnt sure if she was fucking a human or not, saying that my aesthetic had gotten very animalistic, she likes it when i make animal noises :wink: Gaaaaahhh I love this girl, and psychs have gotten us so much closer! It was like I was inside her soul space and dropped a download of my information as our DNA tango'ed.' http://www.shroomery.org/forums/showflat.php/Number/17415943

Marijuana helps to disinhibit people of the guilt and restraint they may have picked up in the past. It gives them the freedom to respond to each other in terms of here-and-now, rather than in terms of the constrictions they may have learned as they were maturing—then it heightens and enhances such love associated phenomena as tactile sensations, so that touching becomes immensely pleasurable The period of foreplay is, or appears to be, greatly prolonged. There is no rush to reach orgasm. And finally, marijuana opens up the associational bank of the mind, which then adds the fantasy. And fantasy is very important when it comes to good sex---I  feel that most of our sexual hang-ups stem from our puritanical training, from too much censorship. And for some people, marijuana may be a first, awakening step.---Reverend L. (Sutton (Methodist), National Sex and Drug Forum

I'm saying simply that sex under LSD becomes miraculously enhanced and intensified. I don't mean that it simply generates genital energy. It doesn't automatically produce a longer erection. Rather, it increases your sensitivity a thousand percent. Let me put it this way: Compared with sex under LSD, the way you've been making love no matter how ecstatic the pleasure you think you get from it is like making love to a department-store window dummy. In sensory and cellular communion on LSD, you may spend a half hour making love with eyeballs, another half hour making love with breath. As you spin through a thousand sensory and cellular organic changes, she does, too. Ordinarily, sexual communication involves one's own chemicals, pressure and interactions of a very localized nature in what the psychologists call the erogenous zones. A vulgar, dirty concept, I think. When you're making love under LSD, it's as though every cell in your body -- and you have trillions -- is making love with every cell in her body. Your hand doesn't caress her skin but sinks down into and merges with ancient dynamos of ecstasy within her. Chapter 7: She comes in colours

LSD is a specific cure for homosexuality. It's well known that most sexual perversions are the result not of biological binds but of freaky, dislocating childhood experiences of one kind or another. Consequently, it's not surprising that we've had many cases of long-term homosexuals who, under LSD, discover that they are not only genitally but genetically male, that they are basically attracted to females. The most famous and public of such cases is that of Allen Ginsberg, who has openly stated that the first time he turned on to women was during an LSD session several years ago. Bui this is only one of many such cases. Chapter 7: She comes in colours

An extremely attractive girl came down to our training center in Mexico. She was a Lesbian and she was very active sexually, but all of her energy was devoted to making it with girls. She was at an LSD session at one of our cottages and went down to the beach and saw this young man in a bathing suit and flash! for the first time in her life the cellular electricity was flowing in her body and it bridged the gap. Her subsequent sexual choices were almost exclusively members of the opposite sex. Chapter 7: She comes in colours

LSD is also a powerful panacea for impotence and frigidity, both of which, like homosexuality, are symbolic screw-ups. The LSD experience puts you in touch with the wisdom of your body, of your nervous system, of your cells, of your organs. And the closer you get to the message of the body, the more obvious it becomes that it's constructed and designed to procreate and keep the life stream going. When you're confronted with this basic cellular fact under LSD, you realize that your impotency, or your frigidity, is caused by neuropsychological hang-ups of fear or shame that make no sense to your cells, that have nothing to do with the biochemical forces inside your body urging you to merge and mate with a member of the opposite sex. Chapter 7: She comes in colours

we've found that in giving LSD to members of monastic sects, there has been a definite tendency for them to leave the monastic life and to find a mating relationship. Several were men in their late 40s who had been monks for 15 or 20 years, but who even at this mature age returned to society, married and made the heterosexual adjustment. It's not coincidental that of all those I've given LSD to, the religious group -- more than 200 ministers, priests, divinity students and nuns -- has experienced the most intense sexual reaction. And in two religious groups that prize chastity and celibacy, there have been wholesale defections of monks and nuns who left their religious orders to get married after a series of LSD experiences. The LSD session, you see, is an overwhelming awakening of experience; it releases potent, primal energies, and one of these is the sexual impulse, which is the strongest impulse at any level of organic life. For the first time in their lives, perhaps, these people were meeting head-on the powerful life forces that they had walled off with ritualized defenses and self-delusions. Chapter 7: She comes in colours

Sex and Drugs:  A Journey Beyond Limits by Robert Anton Wilson

[2016]  Is Cannabis An Aphrodisiac?