why switch to low ph cleansers

I didn’t have a clue what I was doing with my skin when I was a teen.

Back then, I’d just buy the cheapest cleanser I could find. They were usually the foaming kind that left my skin squeaky clean.

I thought that tight feeling I always got afterwards was proof the cleanser was doing its job well. No chance the tiniest speck of grime was still on my skin. Ah!

So what if my skin was oilier than usual and pimples made a frequent appearance on my face? I was a teen. Ever heard of hormones? I blamed them for everything.

But my skin didn’t get any better when puberty ended (and not a moment too soon, if you ask me!). My skin was still an oily, pimply mess. Was I cursed or something? *sighs*

I felt like that until I heard about the low pH life. Switching to an acidic cleanser (that’s a cleanser with a low pH, FYI) was a game changer.

Now my skin finally behaves. It’s stopped pumping out so much oil. It doesn’t feel tight and sensitive as it used to. I don’t even get pimples that often anymore.

Intrigued? Here’s why you should commit to the low pH life too:

What Is Ph?

pH stands for “power of hydrogen” and measures the acidity vs alkalinity of a solution of water + something.

pH 7 is the neutral point. Anything below it is an “acid” and anything above it a “base” (or alkaline).

The pH of your skin’s protective barrier (a.k.a. “acid mantle”) is between 4.5 and 5.5 (I know, the name gave it away 😉 ). This barrier does two very important jobs:

  • It keeps water into your skin, so that it stays soft and hydrated
  • It keeps germs, bacteria and pollutants out of the skin, preventing infections and irritations

When your acid mantle is intact, your skin is moisturised and healthy. But when it starts to crack, your skin becomes dry, sensitive and more prone to irritations.

So you just need to make sure it stays intact, right? It’s not so easy. Anything you put on your skin has its own pH and so affects the pH of your skin. Put another way, what you use on your face can destroy this protective barrier.

Cleansing is one of the biggest culprits.


If you’re into DIY, you can adjust the ph of a substance and make it  more acidic or more alkaline. But depending on what you use, you could create new and unwanted chemicals in the solutions. In other words, study some basic chemistry to know what you’re doing or leave the job to the professionals. Don’t follow random recipes online, especially those that use baking soda or lemon. Their high pH will destroy your skin’s acid mantle.

Related: Acid Mantle: What It Is And How To Repair It

Struggling to put together a skincare routine that banishes excess shine, blackheads, and acne? Download your FREE “Best Skincare Routine For Oily Skin” to get started (it features product recommendations + right application order):

Why The pH Of Your Cleanser Matters

Cleansing changes the pH of your skin.

Even normal tap water alone is enough to do the trick. A 1999 study compared the cleansing powers of tap water, liquid soaps and bar soaps and found that:

Each cleansing agent, even normal tap water, influences the skin surface. The increase of the skin pH irritates the physiological protective ‘acid mantle’, changes the composition of the cutaneous bacterial flora and the activity of enzymes in the upper epidermis, which have an acid pH optimum.”

In other words, every time you wash your face, you’re raising the pH of your skin and disrupting the acid mantle. You’re removing too much oil, making holes in the shield and weakening its natural defences.

When you disrupt the acid mantle, bad things happen:

  • Moisture evaporates, drying out the skin
  • Skin feels tight
  • Skin can’t protect itself from the environment and becomes more sensitive
  • Germs and pollutants get in, irritating skin
  • Bacteria proliferate, causing acne and breakouts

Scary huh? If you’re prone to acne, you have one more reason to switch to a low pH cleanser.

vichy purete thermale one step cleanser

Higher PH = Acne Galore

There’s a reason why your skin’s acid mantle is acidic. An acidic pH is NOT bacteria-friendly.

But when you raise the pH up several notches, bacteria suddenly find the perfect environment to proliferate and thrive.

A 1995 study tested the impact of cleansing on acne-prone skin. Scientists asked patients with inflammatory acne lesions to use either soap or an acidic cleanser for three months. The results?

Only one month later, the group using soap had way more lesions than before. The group using an acidic cleanser had the opposite result: they had fewer lesions than before!

In other worse: high pH soaps make acne worse while acidic cleansers help clear acne up. 

The reason? As this study shows, when you wash your face with soap, P. Acnes (the bacteria that causes acne) proliferates. You have a lot of those nasty buggers on your skin. But when you switch to an acidic cleanser, the amount of P. Acnes bacteria on your skin falls down significantly.

In other words, an acidic cleanser makes your skin inhospitable to P. Acnes and other bacteria.

So if you’re washing your face a lot in the hope of getting rid of shine and pimples, you’re only making things worse. 🙁


Foaming cleansers are usually the worst culprits because they use surfactants (ingredients that help water with mix oil and dirt so they can be rinsed away) that raise the skin’s pH. For a list of safe, low pH foaming cleansers, click here.

Related: Adult Acne: Why It Happens And How To Treat It

cerave hydrating cleanser

Is Raising The pH For Only A Few Hours Really That Bad?

You’ve probably heard the pH of your skin eventually goes back to normal after cleansing.

That’s true. But it takes its sweet time to do so. More than 90 minutes, sometimes. In the meantime, your skin will be overly oily or overly dry. *sighs*

And that’s just the short term effects. Studies show that washing your face with a high pH cleanser regularly (and you do wash your face every day, don’t you?) has a cumulative effect and increases the time your skin takes to recover.

You’ve probably noticed this first hand, especially in winter. The more you wash your hands (or face, for that matter), the drier they get. It’s the same for your skin. That tight feeling you get after washing is a tell-tale sign your acid mantle is compromised.

This may also be why the rest of your skincare routine isn’t working anymore. If you’re using hyaluronic acid serums, moisturising oils and co and you find your dry skin isn’t getting any better, chances are your cleansing habits have badly disrupted your acid mantle. Until you fix that, your skin will never go back to normal.

Related: Are Foaming Cleansers Bad For Skin?

How Can You Tell The pH Of A Cleanser?

Bad news: you can’t tell the pH of a cleanser just by looking at it. The packaging doesn’t tell you. *sighs*

The best you can do is:

  • Avoid bar soaps. They only work at a high pH (yes, even natural ones).
  • Buy a bunch of pH strips and test your cleanser yourself (I know, a pain!).
  • Check out this handy spreadsheet with popular cleansers and their pH (thanks to the Asian Beauty community on Reddit).
  • Use milky and oil-based cleansers: Unlike foaming cleansers, they’re already pH-friendly.

Or you can save yourself the hassle and check out my fave low pH cleansers below:

The Bottom Line

The pH of your cleanser matters. Opt for acidic cleansers that don’t compromise your skin’s acid mantle and watch your skin say goodbye to dryness, sensitivity and pimples.