Lubricants for conducting internal vaginal exams come in a variety of product types, each containing a number of different ingredients.
The most important factor to consider when selecting a vaginal lubricant product, as with selecting any product that will be used internally, is the effects the ingredients can have on the vagina’s pH levels, mucous membranes, and overall health.
The vagina’s natural pH levels are a balance of alkalinity and acidity. A healthy vagina is more acidic, as it is the acidity level that controls and limits the numbers of organisms that live inside the vagina. Normal vaginal pH levels range between 3.5 and 4.5 amongst sexually mature women (1). For menopausal women, the level is around 6.5 (1). When the natural pH balance is altered, for instance, during pregnancy or as the result of using hormonal birth control, there is potential for the number of organisms (like the yeast fungus) to grow, causing infection (1).
Disturbances in the pH level of the vagina are additionally linked to Bacterial Vaginosis (BV), which is caused by the growth of various types of infectious bacteria (2). Like yeast, these organisms are also naturally present in the female body, but their overgrowth in vagina (often triggered by a shift in pH level towards a more alkaline and less acidic composition) can lead to infection (2). BV is a serious form of vaginal infection, because - while it is often asymptomatic - it can lead to heightened susceptibility to Pelvic Inflammatory Disease and sexually transmitted disease, including HIV (2).
Maintaining a healthy vaginal pH level, therefore, should be considered an important aspect of women’s health. Consequently, choosing products, including lubricants, which do not interfere with these levels, is an important choice for physical therapists using products on their patients or making recommendations.
Petroleum-based lubricants, (which contain mineral oil, Petrolatum, or Paraffin Oil), as opposed to water-based, water-soluble products, are inexpensive and readily available. Oil based lubricants do not evaporate or soak into the skin, making reapplication unnecessary. However, lubricants that cling to the vaginal walls can harbor bacteria that lead to infection (3). Petroleum-based products are also easily contaminated with impurities.
Silicone products, as opposed to water-based products, are similar to petroleum-based products in that they do not flush out of the vagina or off the body as easily. Because they contain no water, they do not evaporate or absorb into the skin, meaning they must be washed off with soap and water. Because they do not evaporate, silicone products last longer and require few re-applications. Silicone are sometimes preferred for treating patients that have under gone radiation treatment (5).
Lubricants containing glycerin, a sugar derivative, also have potential side effects, as sugar derivatives can ferment at body temperature and cause yeast to grow more rapidly and lead to infection (3). Additionally, glycerin can be harmful to patients with chemical hypersensitivity. Menopausal women occasionally experience a heightened sensitivity and susceptibility to chemical allergies, due to decreased hormone production and the thinning of the vaginal tissue, meaning products containing glycerin may not be the optimal choice for post menopausal patients.
Parabens are another common ingredient that has come under scrutiny from the medical research community. Studies show that women diagnosed with breast cancer have a high level of parabens in their bodies (4). Though this study has not demonstrated a conclusive causation, the correlation was compelling enough to prompt the EU to ban parabens in household items. However, in the United States, these chemicals are still commonly used in food packaging, cosmetics, and in personal lubricants.
Lubricants containing propylene glycol should also be avoided. Propylene glycol is a volatile liquid, similar to pure alcohol, produced by the fermentation of yeast or other carbohydrates. This chemical is used in hydraulic fluid and industrial anti-freeze. In cosmetics, Propylene glycol is a common ingredient in hair and skin care products, because it is a penetration enhancer, making the skin or hair more absorbent of the other chemicals contained in the product, as well as a humescent, which leads to moisture retention by the skin. In the vagina, this chemical penetrates the sensitive tissue of the mucosa membranes, while simultaneously making them more susceptible to other chemicals.
The most important thing to remember when purchasing vaginal lubricants is that the vagina represents a delicate ecosystem that is susceptible to even minor disturbances. A careful review of the ingredients is the best course of action before purchasing products.