On the full moon, prepare the following in a large soup pot: a dozen oysters, one bunch of asparagus, a full bottle of red wine and at least a few pills of horny goat weed. Or is it 15 drops of Spanish Fly? Either way, bring to a boil, leave to simmer for one hour and dump it all down the drain because that sounds like a rancid tasting recipe full of hackneyed folk aphrodisiacs, which I am (hopefully very obviously) joking about preparing. (Thankfully, this joke is marginally funnier than my other one about looking under the couch.)
Joking aside, you should think about the last place you had a comparatively strong desire for sex and the difference between then and now. What changed in your life? Desire ebbs and flows, and is punctuated by psychological and physical demands. Big life changes (house, work, kids, social life) can raise you into such a heightened state of mental alert that it leaves your whole system too exhausted for anything sexual. Aside from that brain of yours, take note of the rest of your body. Has your diet changed? Are you taking any new medication? Are you exercising? If you’re really concerned about this it would be a good idea to take a step away from Internet advice columns and visit your physician for a full exam to see how your overall health is doing.
If nothing I mentioned above is a factor and everything is exactly how it was the last time you felt the level of desire you’re currently missing, go on a sexy quest. Find out what else in the world turns you on. We humans are into endless variety and novelty for stimulation and you may simply be bored. Make a list (a really common suggestion from me, I love lists, lists are awesome) of things you think you might want to try. Skim the surface - or even plunge the depths - of the Internet for ideas. Buy toys, sample them and discard them. The goal should not be an orgasm but pure stimulation. Your quest of sexy should only be to answer the question: "What else in the world excites me?"
Or, you know, look under the bed. We leave the strangest things under there sometimes.