Personal lubricants have long had a bad rap. "It's just so funny that it's got this reputation of, 'Oh, I don't need to use that,' because it can be a lot of fun for so many couples," says Vanessa Marin, sex therapist. As you experiment with lubricants, however — and you should — be mindful of what's in them. After all, these products are going on the most sensitive parts of our bodies. Women, in particular, are susceptible to problems that may be caused by ingredients in lubes. "The pH and bacteria levels of the vagina are very sensitive, and it is important to choose products that will not disrupt that," says Carlen Costa, sexologist and relationship therapist. Using the wrong products can lead to irritation and unwanted bacterial growth. Fortunately, it's fairly easy to find a more natural lube, so long as you know what to look for.