Check the Ingredients – Propylene Glycol

Once upon a time, we knew nothing about lubricant

We went to a sex shop, we bought the recommended water-based lube and we used it for years. 

When we started to review sex products, we were offered free lubricant from the same company and we jumped with joy because a) we loved their lube and b) we were new to blogging and someone had said YES!

We reviewed the first one within our typical 4-week timeline and then life got in the way and we kept postponing the reviews of the other lubes. During this time, we learned a lot about lubricants and the ingredients that go in them. 

Recently, I set aside some masturbation time to focus on the lubricant we had been sent. 

And then right before I was about to pour one of them… I read the ingredients

Propylene glycol was in all of the water-based lubricants, including that very first lube that we had bought so many years ago! 

Pink Lubricant Propylene Glycol

Here is the issue with propylene glycol:

1. Propylene glycol can cause allergic reactions

“Propylene Glycol – a chemical derived from petroleum […] is a sensitizer, meaning the more you’re exposed to it the more likely you are to have allergic reactions to it.” – Smitten Kitten, 2015.

Translation: If you’re allergic to it, it will only get worse with more use.


2. Glycerol and propylene glycol increase the osmolality of lubricants

“The primary factor determining the osmolality of the majority of lubricants is the concentration of glycol. Glycols are added as humecants/moisturizers [which stops lube from drying out]. Glycerol and propylene glycol are most commonly used. ” – WHO, 2012.

Translation: Propylene glycol increases the osmolality of lubricants, which is not a good thing.


3. They often increase the osmolality above the recommended amount

“The normal osmolality of female vaginal secretions is 260–290 mOsm/kg and in human semen it is 250–380 mOsm/kg. Ideally, the osmolality of a personal lubricant should not exceed 380 mOsm/Kg to minimize any risk of epithelial damage. […] Given that most commercial lubricants significantly exceed this value, imposing such a limit at this time could severely limit the options for sourcing personal lubricants for sector procurement. It is therefore recommended on an interim basis that procurement agencies should source lubricants with osmolalities of not greater than 1200 mOm/kg.” – WHO, 2012.

Translation: The recommended osmolality should be similar to the normal osmolality of the vagina (250-380 mOsm/kg). However at the time of WHO’s research, most brands were high above this so they had to recommend a WORLD recommendation. Four years later, there are many lubricants that have a similar osmolality to a vagina.


4. High osmolality has health consequences

“Hyperosmotic lubricants dehydrate the body’s mucus and mucous membranes, and if they have a drastically higher osmolality this dehydration is so complete that the cells die and slough off, leaving the body irritated and more susceptible to infection.” – Smitten Kitten, 2015

“Several papers suggest that lubricants with high osmolality might cause vaginal and anal epithelial damage. […] Epithelial damage could in turn increase the risk of infection, for example by HIV and other sexually transmitted infections (STIs).” – WHO, 2012.

Translation: High osmolality can cause damage to the cells in your vagina or anus, which can increase your risk of infection. 


Gun Oil Lubricant Propylene Glycol

While Gun Oil does discuss the effects of small amounts of Propylene Glycol on their website, they do not discuss the increase in osmolality. 

WHO does list the Gun Oil H2O Gel as having an osmolality of 3955 mOsm/kg. That is more than TEN TIMES vaginal osmolality as well as more than TRIPLE the maximum recommended amount. 

Please note the propylene glycol is not found in their silicone lubricants. This is because the humecants/moisturizer properties of propylene glycol are only required in water-based or hybrid lubricants. 

We’re kinda bummed out that this happened, although we are super relieved that we procrastinated on these reviews. When we received them, we didn’t know about potential problems with propylene glycol, which means that we would have reviewed lubes that might have irritated my vagina. 

Side note: There is no need to gender lubricants but if you’re going to gender them anyway and make them evidently “pink for women” and “guns for men”, then at least match the osmolality of a vagina!

Our conclusion? We will not be reviewing any Gun Oil or Pink Lubricant products. We will also be paying much closer attention to lube ingredients. 


If you need more information, check out these sites:

  1. Dangerous Lilly: The Big Lube Guide
  2. DizzyGirl: Water-Based Lube – What You Should Know
  3. Sexational: Learn It, Know It – Osmolality, AKA Lube Science
  4. The CSPH Guide to Lube
  5. Smitten Kitten’s Shopping Guide to Lube
  6. Use and procurement of additional lubricants for male and female condoms: WHO/UNFPA/FHI360

If you’re looking for a lube to use, please feel free to contact us! We highly recommend Sliquid, System Jo‘s improved formulas and Hathor Aphrodisia

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  1. BOOOOO Propylene Glycol!! There’s a lot of baddies for lube ingredients that aren’t discussed enough, but this is definitely the most common culprit. Glad to see so much detail put into this – good job!

    • Thanks! I was so mad about this! I had been using the Pink Water lube for years!!! I also used to chronically get yeast infections, and although they aren’t technically related, I can’t imagine that it didn’t have an effect.

  2. Hi, great post we’ve been in a similar situation. Found a great lube, used for ages, unavailable on re ordering, bought product flashed up by website. Long story short, interrupted sessions due to burning sensations! Fortunately a few lovely people on various forums pointed us in the direction of Sliquid and, wow. What a product! Bought two bottles (offer) early June we’ve barely used half of the first. Awesome, unintrusive, odourless, tasteless (which we prefer) product that shortly after initial application you don’t know is there!

    Shame we like many others learnt the hard way.

    • Hey! So sorry for the delayed reply. We moved this weekend and so our internet presence has been limited.

      So glad that you found your way to Sliquid – they really are great. The Sliquid H2O is our current ‘go to’ water lube and the Sliquid Silk is our ‘go to’ hybrid lube.

      I still have a hard time understanding companies who should understand that science behind their products but ignore the health risks. Sigh…

      Sorry you had to go through all of that, but glad you ended up with Sliquid!

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