No matter if you have anal or vaginal sex, lubrication usually makes the sex more comfortable. It’s reducing the risk of minor wounds and injuries on the mucous membranes inside the ass or vagina. Lube can, of course be used for other types of sex as well. Silicon-based lube also makes an excellent massage oil.
Cremes that contain fat (such as ointments, skin lotions, massage oils and other oils), weaken latex condoms and can make them break easily. Instead, it’s better to use either a water or silicon-based lubricant if you’re using a condom. Water-based lubricants are thick and may dry out after a while, so you’ll need to apply more as needed. Silicon-based lubes are thinner, don’t dry out and last a long time, even if you don’t use a lot. Both can be washed off with soap and water, even though silicon lubes are slightly harder to rinse off. If you prefer to use oil based cremes you can always use plastic condoms, they are not usually avaliable in regular stores so you might have to order them online.
You can buy lube at the pharmacy, online and at some supermarkets. Sex shops and condom shops generally have a bigger selection. Feel your way and try out different kinds of lube, and see what’s best for you.