Choosing Lubricants

Lubricants are usually desireable and sometimes a necessity...

For vaginal sex they can supplement a womans natural lubrication, making for a better experience for both partners.

For anal sex and the use of sex toys they are prettymuch essential.

There are three main types of lubricants, plus other "speciality" lubes :

Water-based : Water-based personal lubricants are water-soluble and are the most widely-used personal lubricants - they're smooth and slick, but not sticky and messy like silicone and oil-based lubes can be.  Because water-based lubricants are absorbed into the skin and will evaporate, water-based lubricants can dry out during use... reapplication of the lubricant or the addition of water or saliva is usually sufficient to reactivate them.  Some newer water-based lubricants are formulated with natural skin moisturizers.   Cleaning-up after using water-based lubricants is easy - just a little warm water, maybe some soap, and the lube will easily wash off the skin.  Water based lubes are condom-safe.

Oil-based : Oil-based lubricants tend to be longer-lasting than water based ones but are not suitable for use with condoms.  There are also some concerns for vaginal health regarding oil-based lubes so these tend to be most popular for male solo masturbation. 

Silicone-based : Silicone-based lubricants do not contain any water and offer a different feel from water-based lubricants as they are generally much greasier despite being thinner. Silicone-based lubricants are not absorbed by skin or mucus membranes, and consequently last longer than water-based lubricants.   Silicon-based lubes also work in water so are ideal for bathroom fun but this also means they are not so easy to clean up after. Silicone-based lubricants are not usually recommended for use with sex toys or other products that are made from silicone because they may dissolve the surface making it sticky to the touch, and cause disintegration of the item over time.  Pre-lubricated condoms use silicone-based lubricant and it's generally considered to be condom-safe.

Speciality lubricants : Warming lubricants contain specific ingredients to cause a sensation of warmth. Breathing on these types of lubricants may increase the effect. "Cooling" or "tingling" lubricants may contain ingredients such as peppermint.