Personal lubricant
Personal lubricants (colloquially termed lube) are specialized lubricants used during sexual acts, such as intercourse and masturbation, to reduce friction to or between the penis and vagina, anus or other body parts, or applied to sex toys to reduce friction or to ease penetration.
The viscosity of these products can be altered by adjusting their water content and concentration of cellulose or other gel-forming hydrophilic ingredient.
The Population Council, in a 2011 study, tested commercially available water-based sexual lubricants, and found that many damaged human rectal cells and that some of them – those containing polyquaternium-15 – appeared to actively increase HIV replication in cell cultures and therefore could raise one's risk of HIV transmission.
[7][8] Silicone-based lubricants are not usually recommended for use with sex toys or other products that are made from silicone because the formula may dissolve the surface, making it sticky to the touch, and cause disintegration of the item over time.
Silicone-based lubricant is also used in the manufacture of pre-lubricated condoms, due to its long-lasting properties and superior latex compatibility.
[16][20] Such lubricants are therefore unsafe for use during fertility procedures such as semen collection[11][13][14][17] or by couples trying to conceive by natural or assisted reproduction.
Additionally, a commonly used numbing agent benzocaine can cause an allergic reaction in those with an allergy to PABA (4-aminobenzoic acid).
Many of these types of lubricants also market themselves as "natural" and do not contain parabens, glycerin, diethanolamine (DEA) or animal-based ingredients.
Personal lubricants are particularly useful for intercourse when a partner experiences dryness or excessive contraction (tightness) of the vagina or anus.
Hand lotion is often used for recreational masturbation and popularly seen as an alternative to lubricants created specifically for sexual intercourse.
[32] Enema nozzles[33][34] and rectal thermometer tips should be lubricated before use to minimize friction while inserting through the tightly retentive anal sphincter.
[citation needed] The agency classifies them as medical devices, so testing occurs on animals such as rabbits and guinea pigs.
[citation needed] In 2012 it was reported that participants who consistently used personal lubricants for rectal intercourse had a higher prevalence of sexually transmitted infections (STI), such as chlamydia, than inconsistent users.
[citation needed] Some warming lubricants have been shown to have an osmolality count more than 30 times the body's own fluid.
Lubricants with osmolalities closer to that of the body, such as agar-based lubes, did not damage the tissue samples or boost HIV infection rates.
[7] Nonoxynol-9, a spermicide contained in some lubricants, can destroy vaginal and rectum cell membranes which may increase the rate of STI transmission.
