Study: Glycerin & Propylene Glycol in Personal Lubricants and Their Effects on Vaginal Tissue Damage
An independent review exposing the risks of chemical, synthetic, and petroleum-derived ingredients in lubricants—and their impact on women’s health.
Study: Glycerin In Personal Lubricants & Its Effect On Vaginal Tissue Damage
An independent review exposing the risks of high-glycerin lubricants and their impact on women’s health
Has Glycerin or Propylene Glycol Burned You Or Someone You Know?
If you’ve used personal lubricants in the past decade, you might have been exposed to high levels of glycerin — a chemical compound that, in elevated concentrations, may cause irritation or even chemical burns to sensitive vaginal tissue. Additionally lubricants with propylene glycol that can cause dryness also, and in high blood concentrations can cause toxicity leading to cardiac arrhythmia, seizers, and more.
This article was born from firsthand experience. After years of battling vaginal dryness, discomfort, and stinging — and being handed product after product by doctors that only made things worse — the author began digging into the research. What started as personal investigation turned into something deeper: a study of how one widely used ingredient could be quietly harming countless women.
What Is Glycerin?
Glycerin, also known as glycerol, is a colorless, odorless, viscous liquid widely used in pharmaceuticals and personal care products. Glycerin functions as a humectant, meaning it attracts water to itself, not necessarily to your skin, and is commonly found in lotions, soaps, and lubricants. In theory and practical applications in topical moisturizers typically used on your face and non-mucous membrane areas, glycerin is added to draw moisture to the skin.
In low concentrations and humid environments, this can help hydrate skin or mucosal tissue. In conventional skincare—especially for external, non-mucous membrane areas—glycerin can help maintain hydration by drawing moisture from the air. But in high concentrations or dry air, glycerin can actually pull moisture from the deeper layers of your skin or tissues, leading to dryness, tightness, or irritation.
The Three Sources of Glycerin
Most consumers assume glycerin is a harmless plant-based ingredient—but that’s not always the case. Glycerin can come from three different sources, and manufacturers are not required to disclose which one they use:
Vegetable-Based Glycerin
Derived from oils such as coconut, soy, or palm, this is the most desirable form for those seeking plant-based or “natural” products. It’s often marketed as organic or eco-friendly—but even vegetable glycerin can cause issues if used in high concentrations on internal tissue.Animal-Based Glycerin
Sourced from animal fats as a byproduct of soap or meat processing. This form may be used in pharmaceutical or industrial applications and is generally not vegan or cruelty-free. Brands rarely disclose animal sourcing unless specifically asked.Petroleum-Derived Glycerin
Synthesized from petrochemical feedstocks, this is the cheapest and least “natural” form. It’s chemically identical to other types of glycerin, but the source alone raises red flags for those concerned with clean, non-toxic products—especially for internal use.
Typical Glycerin Concentrations in Cosmetics
In most cosmetic products, glycerin is used at concentrations between 3% and 5%. This range is generally considered safe and effective for moisturizing purposes.
How Glycerin Is Intended to Act in Low Concentrations
Glycerin pulls moisture from the air and any surface it contacts, like skin. In moist climates, it can draw in moisture from the air and, in theory, deposit that moisture into the skin when in low concentrations. However, when not in a humid environment — and especially in concentrations higher than 5% — glycerin begins to pull moisture from the skin rather than deposit it.
High Glycerin Levels and Potential Risks
Some personal lubricants contain glycerin concentrations of 30% or higher. Elevated levels of glycerin can increase the osmolality of the product, leading to cellular dehydration and potential damage to vaginal tissues. High-osmolality lubricants have been associated with epithelial cell damage and increased susceptibility to infections. Thus, in addition to being in a dry environment, higher concentrations of glycerin will further pull moisture from the skin — resulting in dryness, irritation, and even burns.
Reported Reactions to Glycerin-Based Lubricants
Many women report immediate burning, stinging, or rawness after using personal lubricants containing high concentrations of glycerin. These sensations are not merely signs of “sensitivity” — they often indicate cellular dehydration and tissue irritation due to glycerin’s high osmolality.
In addition to surface-level discomfort, studies have shown that such lubricants can disrupt the natural balance of vaginal flora, increasing the risk of bacterial vaginosis. Glycerin’s sugar-like structure may also promote the growth of Candida, leading to a heightened risk of yeast infections — especially in women already prone to them.
What is Propylene Glycol?
Propylene glycol is a synthetic compound used in a wide range of products—from antifreeze and processed foods to skincare and personal lubricants. In lubricants, it functions as a humectant (moisture-retainer), solvent, and texture enhancer, helping to dissolve other ingredients and improve glide. It’s also known to enhance absorption, which might sound beneficial—until you realize it may also increase the absorption of potentially harmful chemicals.
While the FDA classifies propylene glycol as “generally recognized as safe” (GRAS) for many uses, its safety has primarily been evaluated for ingestion or external application—not for prolonged use on sensitive mucosal tissue like the vaginal canal. For some users, especially with frequent exposure, propylene glycol can cause burning, itching, dryness, or even allergic reactions. Despite these risks, it remains a cheap and common base in many drugstore lubes.
How Propylene Glycol Is Sourced
Propylene glycol is derived through the hydration of propylene oxide, a petroleum byproduct. This means the substance is petroleum-based and fully synthetic, produced in industrial settings—not extracted from natural or botanical sources. Its widespread use is largely due to its low cost, chemical stability, and ease of manufacturing—not because it’s inherently safe for intimate use.
High Levels of Propylene Glycol and Potential Risks
Why Are Glycerin & Propylene Glycol Used in So Many Lubricants?
The simple answer? They’re cheap, effective on paper, and easy to work with. Glycerin is a common humectant — meaning it draws moisture — and it helps give lubricants a slippery, smooth texture. It’s shelf-stable, blends easily with water, and adds a sweet taste to flavored lubes. From a manufacturing standpoint, it’s a dream ingredient.
Propylene glycol is often used for similar reasons. It’s a solvent and humectant that helps ingredients blend uniformly, prevents freezing, and creates a slick feel. It’s frequently found in industrial and cosmetic products because it’s inexpensive and very adaptable. In cheaper lube formulas, it’s favored for its ability to mimic moisture and preserve consistency over time without separating or requiring refrigeration.
But from a user safety standpoint — particularly when used in high concentrations — it can be a nightmare. Both ingredients, especially when misused, have been linked to tissue irritation, increased infection risk, and even chemical burns on sensitive mucosal areas like the vagina and rectum.
So the bigger questions become:
- Do these manufacturers know it causes issues?
- And if so, why are they still using it — especially in vaginal products marketed to women with dryness, irritation, or menopause symptoms?
- Is it a lack of up-to-date medical awareness?
- Or is it simply easier to keep using what’s cheap and familiar — even if women are being harmed?
These are the questions we should all be asking. And until companies start answering them, women deserve to be warned.
The FDA’s Role in Regulating Glycerin & Propylene Glycol
Glycerin and propylene glycol are both listed by the U.S. Food & Drug Administration (FDA) as “Generally Recognized as Safe” (GRAS) for use in foods, drugs, and cosmetics. However, that designation is based on general applications, not on long-term or repeated use in the sensitive environment of vaginal or rectal mucous membranes.
The FDA does not currently require manufacturers to disclose the origin (plant, animal, or petroleum) of glycerin used, nor does it mandate warnings about the potential effects of high-osmolality ingredients in vaginal lubricants. Unless a product is specifically submitted for medical device approval (which most over-the-counter lubricants are not), the FDA only offers voluntary guidelines. Regulatory action typically only happens after a significant health issue has already occurred and been reported.
This is why independent scrutiny, public awareness, and petitions to demand clearer labeling and stronger oversight are critical—especially when it comes to products that directly affect women’s health.
Why “GRAS” Doesn’t Mean What You Think It Does
Many consumers assume that if a product contains ingredients listed as “Generally Recognized as Safe” (GRAS), it has been thoroughly vetted and approved by the FDA. But that’s not how it works. GRAS status simply means that an ingredient is considered safe under certain conditions and intended uses—not that it has been tested or reviewed for every possible application.
Most over-the-counter personal lubricants do not go through FDA pre-approval unless they are marketed as medical devices, and companies are not required to submit their products for review prior to sale. This often leaves consumers with a false sense of security, believing that regulators are actively protecting them from harm. In reality, unless a problem is widely reported or a public health crisis emerges, many products can remain on shelves for years without scrutiny.
Stinging Isn’t “Sensitivity” — It’s Your Nerve Endings Reacting to Dehydration
When a lubricant causes stinging or burning upon contact with vaginal tissue, it’s often brushed off as the user being “sensitive.” But that explanation ignores the underlying biology.
The reality is this: Stinging is a neurological response to active tissue distress. In the case of high-glycerin lubricants, it’s the result of osmotic dehydration — a process where moisture is pulled out of your cells due to the high solute concentration of the product.
Your vaginal lining contains dense nerve endings, particularly around the entrance and vestibule. When cells begin rapidly losing moisture, those nerves respond the same way they would if you were being exposed to heat or abrasion: with a pain signal.
This isn’t hypothetical. Studies on hyperosmolar lubricants have shown that they can cause epithelial cell damage, thinning of the protective layer, and increased vulnerability to infection. The body recognizes this damage in real time — and the result is that sharp, stinging sensation.
In other words, that “sensitivity” isn’t about your body being too delicate.
It’s about your body trying to protect you.
Personal Conclusion & Lingering Questions
We still don’t know the long-term effects of using lubricants containing glycerin and propylene glycol on vaginal tissue. After uncovering this information — much of which was hiding in plain sight across medical literature and regulatory databases — I’m left with serious questions about the safety of these ingredients and whether they may have impacted my own health.
I’m angry to realize that I have been putting petroleum-derived chemicals inside my body for years — while being told that the burning, stinging, or dryness I felt was just “sensitivity.” Not once did anyone mention that these ingredients might actually be causing cellular damage. Even if someone doesn’t feel the effects now, the potential for long-term harm can no longer be ignored.
And now, armed with data from medical journals, FDA documentation, and peer-reviewed sources — the same resources used by professionals — I’m left with lingering, unanswered questions:
Pregnancy Risks?
What happens when women use these products regularly over years—or during pregnancy? Could synthetic chemicals like propylene glycol affect fertility, birth outcomes?
Cancer & Disease Risks?
Could these ingredients play a role in rising rates of reproductive disorders, autoimmune conditions, or certain cancers? Are manufacturers using petroleum-based glycerin, making it a synthetic chemical by definition?
Neurological, Hormonal, & Other Effects?
And could these ingredients be quietly entering the bloodstream, impacting neurological health, hormonal balance, or other vital systems?
Menopause Risks?
And what about their role in accelerating vaginal atrophy, particularly in postmenopausal women?
Nobody has studied these possibilities in depth — and that’s the problem.
Until there is meaningful oversight, transparent labeling, and targeted clinical research, we are all unknowingly part of an unregulated chemical experiment.
I say this not only as a health advocate, but as someone who has personally been through breast cancer and experienced vaginal atrophy. I’m not accusing these products of causing my condition — but I cannot say with confidence that they didn’t contribute. And until the research is done, that potential must be acknowledged.
Increased STI Risk?
In my personal analysis, one concerning possibility stood out to me during research. An article from DrAxe.com notes that propylene glycol increases the skin’s ability to absorb other chemicals (source). This raises a troubling question:
If it increases skin permeability, could it also make vaginal or rectal tissue more vulnerable to sexually transmitted infections (STIs)?
To be clear, no medical study has confirmed this — but it seems like a reasonable hypothesis to explore. As someone who’s reviewed a large volume of clinical and medical literature, I believe this is one of many questions that researchers, gynecologists, and public health experts should be investigating more thoroughly.
Until proper studies are done, we simply don’t know the answers to these questions.
A Call to Action
As women, we deserve products that nourish and protect our bodies — not formulas that quietly damage us while calling it “normal.”
Here’s what needs to happen next:
Researchers Must Investigate the Long-Term Risks
We need clinical studies examining whether lubricants containing high concentrations of glycerin and propylene glycol contribute to vaginal atrophy, chronic dryness, epithelial breakdown, or increased susceptibility to infection — including potential STI transmission.
Propylene glycol has also been linked in various case reports and toxicology literature to more systemic risks such as cardiac arrhythmias, central nervous system issues, metabolic acidosis, and organ stress in high or cumulative exposures. While most studies focus on ingestion or IV use, its mucosal absorption through vaginal or rectal tissue has not been adequately studied.
These ingredients have gone unchallenged for far too long — and the silence has harmed countless women. It’s time for regulators, researchers, and public health leaders to investigate what we’re really absorbing and the potential long-term effects.
Doctors Must Educate Themselves — and Their Patients
Medical professionals need to understand how osmolality and glycerin affect vaginal health. Recommending over-the-counter products without understanding their formulations is no longer acceptable. If a patient complains of stinging or discomfort, the response shouldn’t be dismissal — it should be investigation and guidance.
Clinical Use of Glycerin & Propylene Glycol-Based Lubricants Must Stop
Medical providers and healthcare facilities must also re-evaluate the lubricants used in pelvic exams, transvaginal ultrasounds, catheter insertions, and other internal procedures. Many sterile lubricants used in clinical settings contain high levels of glycerin and may cause tissue damage over time—especially with repeated exposure. These products are not exempt from scrutiny simply because they’re labeled “sterile.”
We urge hospitals, OB/GYN clinics, and outpatient centers to prioritize patient safety by phasing out high-glycerin formulas and adopting safer alternatives—particularly for procedures involving vaginal or rectal mucosa.
Medical Schools Must Update Their Curricula
It’s not enough for practicing doctors to educate themselves — this information needs to be built into medical training. Universities and residency programs must start teaching future OB-GYNs, nurse practitioners, and general physicians about the risks of glycerin and propylene glycol, especially in relation to vaginal health, mucosal hydration, and menopause care.
Both ingredients are commonly found in over-the-counter and even medical-grade lubricants, yet few medical professionals are trained to recognize their potential role in stinging, chronic dryness, tissue thinning, or other adverse effects. Worse, propylene glycol has been linked in toxicology literature to systemic issues like metabolic stress, cardiac irregularities, and central nervous system effects — but its use in vaginal products has not been sufficiently studied or discussed in clinical education.
Vaginal pain, atrophy, and inflammation shouldn’t be treated like unsolvable mysteries — many cases are preventable. It’s time medical education caught up to the real-world experiences of women and began preparing providers to recognize and address the root causes, not just the symptoms.
Women Deserve to Know What That Stinging Means
That sharp, burning sensation so many women feel after using certain products? It’s not just “sensitivity.” It’s the direct result of moisture being pulled from your cells. It’s not in your head. It’s your body trying to tell you something is wrong.
The FDA Must Require Transparency in Lubricant Labeling
If a product contains high concentrations of glycerin or propylene glycol—especially when intended for vaginal or internal use—it should be required by law to carry a clear and specific warning. Manufacturers should be legally required to disclose the percentage by volume, identify the source of the ingredient (animal-based, vegetable-based, or petroleum-derived), and clearly state the potential effects on mucosal tissue and internal usage, including risks of irritation, cellular dehydration, and increased susceptibility to infection.
Just like cigarette labels or food allergen warnings, women deserve full transparency about what they are putting into the most sensitive and absorbent part of their bodies. If companies won’t disclose these facts voluntarily, then it’s time for legislation that forces them to.
Manufacturers Must Be Transparent
Any product containing 30% or more glycerin or any concentration of propylene glycol should be required to carry a clear warning label. These ingredients have been linked to cellular dehydration, mucosal irritation, epithelial damage, and an increased risk of infections, including yeast and bacterial overgrowth.
Propylene glycol, in particular, has also been associated with systemic side effects such as cardiac arrhythmias, neurological symptoms, and metabolic disruptions in toxicology studies — yet it remains widely used in vaginal and rectal products without proper disclosure.
Women deserve to know when a product may cause real biological harm — especially when it’s applied directly to sensitive internal tissues. Transparency is not optional. It’s a basic matter of informed consent.
Retail Platforms Must Flag Products with Glycerin and Propylene Glycol
Just like food products require allergen warnings, online retailers like Amazon, Walmart, and Target should be required to visibly flag personal lubricants and intimate care products that contain high concentrations of glycerin or any amount of propylene glycol.
These ingredients have been linked to vaginal irritation, chronic dryness, cellular damage, and potential systemic effects — yet major platforms continue to sell them without any health warnings. These corporations profit from products that may harm women’s intimate health; they should be held to a higher standard.
If retailers can flag items for cancer risks, allergens, or shipping delays, they can certainly add a warning for chemical risks in vaginal and rectal products. Women deserve to make informed decisions — not be misled at checkout.
Mainstream Media Must Help Spread the Message
I urge journalists, editors, content creators, and health reporters to help bring visibility to this issue. Millions of women are affected by these products, often without understanding the risks. By reporting on this study and the broader lack of transparency in the personal lubricant industry, you can help spark overdue conversations, influence public health awareness, and push for industry change.
References:
Claim: Glycerin is a Chemical Compound
Glycerin, also known as glycerol, is a simple polyol compound with the chemical formula C₃H₈O₃. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerin is a sugar alcohol, and is sweet-tasting and of low toxicity. Chemondis BlogWikiDoc+1Wikipedia+1
The American Chemical Society (ACS) also recognizes glycerol as a chemical compound, detailing its synthesis and applications in various industries. American Chemical Society
Furthermore, the National Institute of Standards and Technology (NIST) provides detailed chemical and physical property data for glycerin, affirming its status as a chemical substance. NIST WebBook
These sources confirm that glycerin is a well-characterized chemical compound with established properties and uses across multiple industries.
Claim: Glycerin in 3-5% Formulations Commonality
Typical Glycerin Concentrations in Moisturizers
According to a study published in the Journal of Cosmetic Dermatology, glycerin is commonly incorporated into cosmetic products at concentrations ranging from 1% to 5%. Higher concentrations can leave a sticky feeling on the skin, which is generally perceived as unpleasant. CosmEthically ACTIVE certificate
Potential Irritation at Higher Concentrations
While glycerin is recognized for its moisturizing properties, excessive concentrations can lead to adverse effects. A study published in the International Journal of Cosmetic Science found that a 10% glycerin solution caused slight irritation in a 48-hour occlusive patch test, indicating that higher concentrations may not be suitable for all skin types. Safety Assessment of Glycerin as Used in Cosmetics
Furthermore, the American Academy of Allergy, Asthma & Immunology notes that reactions to glycerin are typically irritant responses, and reducing the concentration of glycerin usually alleviates the intolerance. AAAAI
Claim: Glycerin over 30% Concentration Can Cause Skin Burns & Irritation
The following are resources supporting the claim that high concentrations of glycerin can cause burns on vaginal skin.
Myrto Natural Cosmetics notes that glycerin can have a drying effect and irritate mucous membranes at very high concentrations, specifically above 30%. myrto-naturalcosmetics.de
Healthline indicates that undiluted or insufficiently diluted glycerin can dehydrate the skin, potentially leading to blistering, especially in low-humidity conditions. Healthline+1Verywell Health+1
Verywell Health reports that severe dehydration of the skin could result in blistering when using pure glycerin, emphasizing the importance of dilution. Verywell Health
Cosmetics and Skin highlights that applying undiluted glycerin to chapped skin can exacerbate the condition, causing a burning sensation. cosmeticsandskin.com
Claim: Women Reporting Irritation & Discomfort Related to Glycerin in Personal Lubricants
Clinical and Laboratory Findings
Hyperosmolar Lubricants and Vaginal Tissue Damage: A study published in Environmental Health Perspectives found that many personal lubricants are hyperosmolar, meaning they have a higher concentration of solutes than vaginal fluids. This can lead to epithelial cell damage and increased susceptibility to infections. Glycerin, a common ingredient, contributes to this hyperosmolarity. PMC
Impact on Vaginal Microbiota: Research in the journal Contraception demonstrated that certain lubricants, including those containing glycerin, can disrupt the growth of beneficial vaginal Lactobacillus species. This disruption can lead to an imbalance in the vaginal microbiome, potentially causing irritation and increasing the risk of infections. PMC
Clinical Recommendations and Observations
Stanford Health Care Guidance: Dr. Leah Millheiser from Stanford Health Care advises that glycerin can cause yeast infections and recommends that individuals prone to such infections should opt for glycerin-free lubricants. Obstetrics & Gynecology
University of Michigan Rogel Cancer Center: Their guide on improving sexual health suggests avoiding lubricants containing glycerin, as well as flavored or warming lubricants, since they may cause irritation. Rogel Cancer Center
Consumer Reports and Expert Opinions
Healthline: An article on Healthline notes that glycerin, among other ingredients, can cause inflammation or irritation and should be avoided by people prone to vaginal infections or who have sensitive skin. Healthline
SELF Magazine: SELF highlights that glycerin, a common ingredient in lubricants, can lead to yeast infections in some women and advises caution for those with sensitive vaginas or a history of infections. SELF
Claim: A Single Use of a Personal Lubricant with Propylene Glycol Can Potentially Expose You to 4-5000 mg, of which 900 mg can be toxic.
Referencing the information at: https://www.ncbi.nlm.nih.gov/articles/PMC4341412/
And estimating that the average person uses about 1 tablespoon of lube per use, my hypothesis was formed with this logic:
18 mg/dL means 18 milligrams of PG per deciliter of blood. The average adult has around 50 deciliters of blood — so:
18 mg/dL × 50 dL = 900 mg of PG in total circulation before it hits potential toxicity risk.How much PG is in a typical lube dose? Let’s say someone uses 1 tablespoon of lube (about 15 mL). If the lube is ~30% PG by volume (which is plausible for some formulas), that’s:
15 mL × 0.30 = 4.5 mL of PGPG has a density of ~1.036 g/mL, so:
4.5 mL × 1.036 g/mL = ~4.66 grams of PGThus, one typical application of lube could contain 4,000–5,000 mg of propylene glycol — far exceeding the 900 mg threshold noted in the study.
Claim: Stinging Isn’t “Sensitivity” — It’s Your Nerve Endings Reacting to Dehydration
Medical Evidence Supporting Tissue Damage from Hyperosmolar Lubricants
Epithelial Damage and Barrier Disruption: A study published in the Journal of Infectious Diseases found that hyperosmolar lubricants, which often contain high concentrations of glycerin, can cause epithelial damage in the distal colon, suggesting similar effects could occur in vaginal tissues. The study noted that such damage could increase susceptibility to infections. SAGE Journals+1PMC+1
Cytotoxicity and Tissue Irritation: Research published in PLOS ONE evaluated over-the-counter personal lubricants and found that hyperosmolar lubricants were associated with cellular toxicity and epithelial damage, while iso-osmolar lubricants did not show these adverse effects. PLOS+1IMR Press+1
Impact on Vaginal Microbiota: A study in the Journal of Sexual Medicine highlighted that lubricants with high osmolality can disrupt the natural balance of vaginal flora, potentially leading to conditions like bacterial vaginosis.
World Health Organization (WHO) Recommendations
The WHO recommends that personal lubricants should have an osmolality of ≤380 mOsm/kg to minimize the risk of epithelial damage. However, many commercially available lubricants, especially those containing glycerin, exceed this threshold, with some products having osmolality levels several times higher. PMC+1Rogel Cancer Center+1
Conclusion
The stinging and burning sensations reported by users of high-glycerin lubricants are not merely signs of sensitivity but are indicative of underlying tissue damage and dehydration caused by hyperosmolar formulations. These findings underscore the importance of choosing lubricants with appropriate osmolality levels to maintain vaginal health and prevent discomfort.
About the Author
Christie Templeton, founder of Wet Orchid, is a prior Business Analyst who after experiencing menopause, vaginal atrophy, and trying different products that caused irritation, she began researching and formulating her own products which she has since began producing for other women. She spent 2 years researching, writing, and formulating using the same resources that medical professionals use to find solutions for women that go beyond the limited knowledge that is shared about women’s intimate health and the lack of women made products in an industry dominated by male-ran manufacturers.
This is an evolving investigation.
As I continue uncovering more information about harmful and undisclosed ingredients in commercial lubricants, I’ll be updating this article regularly.
Bookmark this page and check back for the latest updates.
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