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A Rabbit Afraid of K-Y Warming Jelly

6 Studies That Put K-Y Under The Microscope

The last time I was at Smitten Kitten I talked to one of their SESAs (sex educator sales associates) about lube.  When I asked what he thought about brands like K-Y his response was an “Oh we hate K-Y here”, then gave me their lube safety pamphlet.  After reading it, I was inspired to do some research and went looking on PubMed for more studies about K-Y.   Surprise surprise, there’s more bad news than good.

Study 1) Microbicide excipients can greatly increase susceptibility to genital herpes transmission in the mouse

Findings: K-Y Warming Jelly Causes Ten-Fold Increase in HIV transmission

In this study, K-Y warming jelly (KYWJ) was applied to the vaginal tissues of mice.  Twelve hours later the mice were exposed to the herpes virus, and then three days after were checked again.

Compared to the control group, mice exposed to KYWJ were 10 times more likely to contract Herpes.  The scientists believe the main ingredients to cause this are glycerol, propylene glycol, and PEG-8


2) Is Wetter Better? An Evaluation of Over-the-Counter Personal Lubricants for Safety and Anti-HIV-1 Activity

Findings: K-Y Jelly kills Lactobacilli, the vagina’s natural gate-keepers.

This 2012 study was done at the University of Pittsburgh and led by Charlene S. Dezzutti, an HIV researcher.  The goal of the study was to see what personal lubricants helped reduce the risk of HIV transmission.

The safest lubricants were silicone-based and organic water-based lube, and the most dangerous one? K-Y Jelly, which killed all three species of Lactobacilli in the vagina.  Researchers attributed the kill-off to K-Y Jelly’s anti-microbial ingredient chlorehexidine gluconate.

Lactobacilli are a healthy bacteria that occur naturally in the vaginal flora, they keep bad bacteria from growing out of control.  When Lactobacilli is killed, the bad bacteria and fungi grow out of control, leading to B.V., yeast infections, and increased STI suceptibility.


3) Use and procurement of additional lubricants for male and female condoms: WHO/UNFPA/FHI360: advisory note

Findings: K-Y warming gel has an osmolality 27 times higher than the United Nations’s recommended safe level.

The World Health Organization or WHO is an agency of the United Nations that concerns itself with International Public Health. Their teams of scientists analyze new studies and issue health reports and advisories on their findings.

In 2012, WHO made an announcement about the importance of using lubricants with condoms for anal sex.  Studies had shown that lubricant reduced the risk of condom breakage from 21.4% to 3% when used for anal intercourse.

In this same report, they advise avoiding lubes with an osmolality above 380 mOsm/kg.  This advisory is based on four studies that found high osmolalities caused tissue damage. While the osmolality of the vagina is 260-290 and sperm is 380, most lubes on the market had osmolalities well over 1,000.

When measured in a study, K-Y jelly had an osmolality of 2424, 6 times the recommended safe level.  K-Y’s other products like K-Y Warming Jelly had an osmolality of 10300, 27 times the safe amount.


4) Effect of Vaginal Lubricants on Natural Fertility

Findings: K-Y has a minimal effect on the ability to conceive


5) Hyperosmolal vaginal lubricants markedly reduce epithelial barrier properties in a three-dimensional vaginal epithelium model

Findings: K-Y damages the epithelial layer when observed under a microscope.

Done in 2018, this is the most recent study on K-Y.  It is the first step to use 3D vaginal tissue models to test the effects of K-Y.  Dr. Richard Cone says in the introduction that it is the closest thing to replicating the real world reactions.

The test used 10 lubricants on the vaginal tissue and a microscope to show the effects.  Compared to the control, which looks smooth an uniform, the tissue exposed to K-Y was torn up and warped in appearance.

6) Behind the label: K-Y Jelly

Findings: K-Y doesn’t have to display ingredients on the label.

If K-Y has nothing to hide, why wouldn’t they put the ingredients on the label? In this article of the ecologist, the author points out that since K-Y has FDA approval they aren’t required to put ingredients on the label of their product.  The FDA allows this so companies can keep their recipes a secret.  Like other scientists, author argues that the FDA testing process proves that K-Y is safe on the skin, but not on vaginal or anal tissues, where they are actually used.  So the lack of a label prevents people from doing in depth research on the safety of K-Y for themselves.

So Why’s It Still On Most Shelves?

With all this dirt on K-Y, it seems that there are few benefits of using its ingredients.  It continues to be on the shelves though, probably because it has fewer side effects for penises than it does for vaginas and butts.

It’s also strange that K-Y would ignore the United Nations health advisory and continue to make lubes with a high osmolality, despite the scientific evidence above that it’s risky.

You can also check out my big lube guide if you want to learn more about the different types of lube and which ingredients are the healthiest.