Understanding what is pH, when it is important, and when it’s not worth stressing over can help you make better choices. 

What is pH?

You probably remember from school that pH is a measure of acidity or alkalinity on a scale of 0 to 14. A pH below 7 is acidic, a pH above 7 is alkaline, and a pH equal to 7 is neutral. 

EVERYTHING around us has a pH. Including our bodies. And each body part has a certain pH.

The average natural pH of the skin is around 4.5 to 5.5, so it is slightly acidic. This acidity is due to the skin’s natural protective barrier called the acid mantle, made up of a thin layer of oil and dead skin cells. The acid mantle defends the skin against harmful bacteria and maintains skin hydration.

However, some areas are more alkaline, or vice versa, more acidic. Think about the stinkiest part of your body. Did you think about underarms? Well, the pH of the armpits typically ranges from 6 to 7.5. Increased pH allows odor-causing bacteria to overgrow and produce the stink. 

pH and body odor

What do your sweat glands produce? Sweat. What does the sweat consist of? Many things! Primarily it’s composed of water (99%), electrolytes, urea, and other things that bacteria love to consume. Why are there bacteria on your armpits? In fact, they are everywhere, and they are called skin microbiome. Most of these bacteria are beneficial (at least 85% of them), as they protect you from infections and diseases. 

So, some of these bacteria consume the sweat. They also thrive in an alkaline environment. The higher the pH, the more their community grows. As they metabolize what they consume, these bacteria release byproducts that cause body odor. So an increased skin pH creates favorable conditions for bacterial overgrowth, resulting in increased body odor.

A healthy pH will not allow odor-causing bacteria to overgrow. It will keep the skin microbiome balanced. 

By the way, the pH of sweat is 6.3, so it is higher than average skin pH, but still is slightly acidic. And the sweat doesn’t stink naturally.

This is also why acids work so well in reducing and preventing body odor. If you wanna know more about how to prevent BO with acids check out this post: AHA and BHA in personal care – forget about body odor.

And we go on with pH.

pH and skin health

Okay, increased pH promotes bacterial overgrowth that causes body odor. What else does it do?

When the skin pH is imbalanced (either too acidic or too alkaline), it can disrupt the skin acid mantle.

The acid mantle keeps the skin moisturized, supple and prevents dryness and flakiness. It allows your skin to take in enough water and don’t lose too much of it. Imagine a towel in a dry warm environment. If that towel had an acid mantle, it would never get dry. 

The damaged acid mantle is also why your skin feels dry after you get out of the shower – you’ve disturbed your skin’s natural barrier in some way. If so, you may find this post about how to prevent dry skin after shower useful.

pH and vaginal health

You’ve probably heard about the importance of vaginal pH too. The healthy vaginal pH, though it changes depending on the cycle (it gets more alkaline during periods), ranges from 3.8 to 4.5. This acidic environment helps maintain a healthy microbial balance, preventing infections and maintaining overall vaginal health. Any disruption in the vaginal pH balance can disturb this delicate equilibrium, leading to conditions like bacterial vaginosis or yeast infections.

pH-balanced or pH-balancing? Neither!

We got it, keeping a healthy pH on all body parts is important. But how do we do that?

As your skin has a slightly acidic pH you would think you need to choose acidic products: body washes, intimate washes, cleansers, and so on. Well, it’s not that simple!

First of all, let’s see what we have on the market. There are products marked “pH-balancing” or “pH-balanced”. There are also “pH-neutral” products. What is the difference? And which one do you need?

Clearly, pH-balancing products are supposed to balance the pH. How? By being more acidic than your skin. To achieve this effect, brands use citric, lactic, and other types of acids. But, surprise, acids are incompatible with many other ingredients. Some formulations can cause more damage than good with low pH. But wait, more on that later. 

pH-balanced products are formulated to have a pH level similar to that of the target area (skin or intimate areas), ensuring they do not disrupt the natural pH balance. Just like in the previous case, most often they will have acids among the ingredients.

pH-neutral products normally have a pH of 7 or close to it. So their pH is a bit higher than that of your skin, but sometimes it is better than ph-balanced or pH-balancing, I’ll explain in a moment.

And of course, there are alkaline products, their pH is above 7. Most likely you will not find the pH anywhere on the label. These are regular soaps, shower gels, and many other products that you will find on the market.

It’s not all about pH 

The pH of a product is not the sole indicator of its harshness or irritability. In some cases, acidic pH can make a product more harsh.

First of all, you need to understand, that pH is pretty stable and can’t be changed very easily. For example, a study shows that vitamin C in the form of ascorbic acid, wasn’t able to acidify urine (the pH of urine can reach up to 8).

Participants of the study received 500 mg of ascorbic acid four times daily (!), however, urine pH did not decrease, even though it was consumed orally, and went all the way through their bodies.

So can you really expect a pH-balancing wash, that stays on your skin for literally a moment and is then washed off with water, to rebalance the pH? 

pH of a product is truly important, but only when this product stays on the skin.

In most cases, acidifying / pH-balancing / ph-balanced rinse-off products are simply marketing.

When you choose something you’re gonna wash away with water, pay attention to the harshness of this product and the combination of the ingredients (formulation). 

How do I know if a wash is harsh?

Look at surfactants. They are one of the most important ingredients of any wash, soap, shampoo, or any product that is supposed to clean something. 

The four main types of surfactants are:

1. Anionic surfactants are commonly used in household cleaners and personal care products – they are the most popular type. This is also the harshest type.
2. Cationic surfactants are often used in fabric softeners and hair conditioners.
3. Nonionic surfactants are commonly used in laundry detergents and shampoos.
4. Amphoteric surfactants are used in mild personal care products. They are the most gentle and can be beneficial for your skin.

Surfactants have both a hydrophilic (water-loving) and lipophilic (oil-loving) end. The lipophilic end of the surfactant molecule attaches to the oils, while the hydrophilic end attaches to water.

When a harsh anionic surfactant is rinsed off, it takes the natural oils with it, leaving the skin vulnerable. If a product with these surfactants also acidic, it provides chemical exfoliation on your “naked” skin. You may not notice it immediately (or maybe YOU will, depends on your skin), but over time your skin will get more dry, irritated, and itchy.

Try to avoid these types of surfactants (SLS, SLES), especially mixed with low pH, and choose milder amphoteric surfactants. 

Despite being the mildest type among all types of surfactants, amphoteric surfactants make a product’s pH a bit higher: from 5.5 to 6.5. Despite their pH being a bit closer to neutral, they still provide gentle cleansing without disrupting the skin’s barrier function. As a result, they help to maintain a balanced and healthy skin pH while effectively removing dirt, oil, and impurities.

If you’re searching “ph-balancing”, means you are looking for a product with mild surfactants. 

For example, we add amphoteric (linear amino acid-based) surfactants in WASH, which allows to keep the skin subtle. Plus, WASH has a slightly acidic pH of around 6.5, so your skin gets cleaned enough, but is not harmed with too many acids. 

By the way, WASH is indeed ph-balancing! Curious how we achieved it? Even with an almost neutral ph? The answer is simple: prebiotics.

Rebalance skin pH with prebiotics

Prebiotics themselves don’t directly rebalance the skin pH, but they contribute to a healthier pH balance.

Your skin has a microbial community. Any skin problems (acne, dryness, or body odor) mean that the skin microbiome is imbalanced. It also means that the environment in which the microbial community exists – pH level – is out of balance too.

Prebiotics are food for beneficial bacteria. When you put them on your skin, you provide your skin microbiome with nutrients. Good bacteria feed on prebiotics, their number grows, and now they can suppress the opportunistic bacteria which cause the skin problems.

The good bacteria metabolize prebiotics and release byproducts such as fatty acids. The fatty acids are what make the skin more acidic, so, lowers the skin’s pH. Opportunistic bacteria struggle to survive in an acidic environment. So the balance is restored.

Okay, rinse-off products’ pH is not that important. If a product stays on the skin and is acidic, it should be effective. But leave-on products have many properties, other than pH too. Ever heard of osmolality? 

Osmolality

Osmolality measures how concentrated the molecules are in a liquid solution. It tells you how many solute particles there are per kilogram of the liquid (osmol/kg). 

Your skin, mucous membranes, and vaginal fluids consist of cells that are filled with water and also have osmolality. For example, the vaginal fluid of a healthy woman is about 370 +/- 40 milliosmoles per kilogram (mOsm/kg). So the products you apply to your perineal region should have similar osmolality and here is why.

Your skin layers and natural mucus are always trying to maintain a balance of osmolality. If you apply a product with a higher osmolality the tissue will release its moisture in an attempt to reach a balance with the product that you applied.

As a result, instead of making the tissue moisturized, this will pull the water out of the cells and will cause cellular damage. Studies show that such tissue damage increases the risk of bacterial vaginosis, STIs, and eventually urinary tract infections because healthy vaginal flora prevents UTIs.

In one of the studies, the osmolality and the pH of different lactic acid gels were tested. While the pH was perfect for vaginal application, the osmolality turned out to be too high. Regular use of such products can cause tissue damage and inflammation. 

Many of the popular and easily available lubricants and perineal products on the market are hyperosmolar. Manufacturers do not put this information on the labels and it’s even difficult to find it on the Internet. You have to send it to a lab to test.

For example, WipeGel has osmolality of 340 ± 10  mOsm/kg, so, very close to that of vaginal fluid (370 +/- 40 mOsm/kg). 

At the same time, WipeGel is formulated with acidic pH of 4.6 and it makes sense because it stays on the skin and can actually rebalance the pH of your perineal and perianal skin. Prebiotics in WipeGel feed banaficial bacteria, which also promotes healthy flora.

Summary:

1. pH is not the sole factor on which you should build your product choices. 

2. If it is a rinse-off product with an acidic pH, it can’t rebalance the pH of your skin, as it does not stay on it.

3. When choosing a rinse-off product, pay attention to surfactants, opt for mild amphoteric surfactants, and avoid harsh anionic surfactants.

4. Prebiotics can help you restore healthy skin pH by feeding beneficial bacteria, preventing the overgrowth of opportunistic ones.

5. pH matters when a product stays on the skin. In this case, it can rebalance or acidify the skin. 

6. Too high or too low osmolality of a product can cause tissue or skin damage with regular use.