Ep 146 – Percentage, pH, and Everything Else

esthetician applies chemical peel

It’s a long-held debate in the esthetics industry: Does percentage or pH determine the strength of chemical peels? In this episode of ASCP Esty Talk, Ella and Maggie debunk some common myths and discuss other determining factors in the strength of chemical peels and how skin-peeling treatments affect the skin.

ASCP Esty Talk with Maggie Staszcuk and Ella Cressman

Produced by Associated Skin Care Professionals (ASCP) for licensed estheticians, ASCP Esty Talk is a weekly podcast hosted by Maggie Staszcuk and Ella Cressman. We see your passion, innovation, and hard work and are here to support you by providing a platform for networking, advocacy, camaraderie, and education. We aim to inspire you to ask the right questions, find your motivation, and give you the courage to have the professional skin care career you desire.


About Ella Cressman:

Ella Cressman is a licensed esthetician, certified organic formulator, business owner, and absolute ingredient junkie! As an educator, she enjoys empowering other estheticians and industry professionals to understand skin care from an ingredient standpoint rather than a product-specific view.

She has spent many hours researching ingredients, understanding how and where they are sourced, as well as phytochemistry, histological access, and complementary compounds for intentional skin benefits. In addition to running a skin care practice, Cressman founded a comprehensive consulting group, the HHP Collective, and has consulted for several skin care lines, including several successful CBD brands.

Connect with Ella Cressman:

Website: www.ellacress.com

Website: www.hhpcollective.com


About Maggie Staszcuk:

Maggie has been a licensed esthetician since 2006 and holds a bachelor’s degree in business administration from Stephens College. She has worked in the spa and med-spa industry and served as an esthetics instructor and a director of education for one of the largest schools in Colorado before coming to ASCP as the Advanced Modality Specialist. 

Connect with Maggie Staszcuk:

P 800.789.0411 EXT 1636

MStaszcuk@ascpskincare.com or AMI@ascpskincare.com


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About Associated Skin Care Professionals (ASCP):

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0:00:00.5 Speaker 1: DMK is the world leader in paramedical skin revision education with certification programs designed to give licensed professionals a thorough understanding of the skin and an in-depth study of the DMK concept of remove, rebuild, protect, maintain. Created by the botanical visionary Danné Montague-King. DMK offers skin revision training and education for all ages, skin conditions and ethnicities in more than 35 countries, harnessing the body's innate healing mechanisms to change the health of the skin. Learn more at dannemking.com. That's D-A-N-N-E-M-K-I-N-G.com. 




0:00:57.1 Maggie Staszcuk: Hello and welcome to ASCP's Esty Talk. I'm your co-host, Maggie Staszcuk, an ASCP cosmetology education manager. 


0:01:03.5 Ella Cressman: And I'm Ella Cressman, licensed esthetician, certified organic formulator, ingredient junkie and content contributor for Associated Skin Care Professionals. 


0:01:11.9 MS: So, Ella in my opinion, one of the biggest controversies in the aesthetic industry is the debate over pH versus percentage. I was always taught pH is the number one factor when it comes to strength of the chemical peel, exfoliating the skin, and efficacy. Of course, it's not that simple, and there are many other factors that must be taken into consideration but what camp do you fall into?  


0:01:37.3 EC: I think that you nailed it there, there's many other factors to take into consideration, I think pH is the guiding light, I guess, or the guiding standard of chemical peels. When I was in school, we were taught percentages and pH, but it was so confusing and there was a lot of crossover, and even our regulatory board, they gave the classification of chemical peels based on percentages but that went away. And so I think pH is where it's at. 


0:02:10.5 MS: PH is where it's at, totally. So let's start first with the facts. The pH scale describes if a substance is acidic or alkaline. 


0:02:21.3 EC: And this is important. Okay, so historically, we have to respect the fact that pH has a huge influence on our industry, going back to Dr. Bronner's soap, so you know that Dr. Bronner's soap that has all the messages on the label?  


0:02:34.9 MS: Right. 


0:02:36.6 EC: That's actually where the term "Being on a soapbox" comes from. 


0:02:40.6 MS: No kidding. I didn't know that. 


0:02:41.3 EC: Because when he was peddling his soap, he would be on a soapbox, speaking his... 


0:02:46.6 MS: Speaking his truth. 


0:02:47.7 EC: His the truth and standing firm in what he believes in, and preaching and so that's standing on your soapbox. Anyways, I digressed. Soap before, soap as we knew it then was alkaline. So face soap was alkaline, and that's why we have toners or we had toners, was to bring the pH back into balance. 


0:03:08.9 MS: You know what I always think about? Not to cut you off, but is the movie Fight Club?  


0:03:14.6 EC: Okay, I wanna hear this. 


0:03:18.2 MS: When he is holding the guy's hand and he's dumping this stuff on the hand and it bubbles up and it's burning and blistering, and it's not because it's acidic, it's because it alkali or base. 


0:03:31.5 EC: Yep. 'Cause it's bringing it back. Think of vinegar and baking soda. The volcanoes that is very similar. 


0:03:40.0 MS: Okay, next fun fact, pH scale ranges from 0-14. One of the first things we learn in aesthetic school, right?  


0:03:46.5 EC: And chemistry, in high school chemistry. 


0:03:48.6 MS: Well, I don't remember that far back. 


0:03:49.9 EC: So, what's neutral?  


0:03:53.0 MS: Seven, seven. 


0:03:53.3 EC: Oh my God, it's crazy. 




0:03:57.2 MS: PH scale is also measuring the presence of hydrogen ions in a solution. I think that's one thing that as estheticians we're not thinking about and maybe understanding, but it is applied when we're talking about galvanic current. And that's a whole another topic. 


0:04:09.2 EC: I think we're gonna hear more about this organic chemistry, and we talk about when we're talking alpha hydroxies, molecular structure size, but I think we're gonna hear more coming in the next... I don't know, maybe this is a prediction. Let me get on my soapbox, but I feel like we're going to hear more about the science of the solutions we use and understand this a little bit more. 


0:04:34.3 MS: Totally. So the number of hydrogen ions in a solution, this is determining whether a solution is acidic, basic or salt being neutral. 


0:04:44.1 EC: Nobody wants to be basic. 




0:04:46.0 MS: Or salty. 


0:04:47.9 EC: Well, [laughter] guilty. Sometimes I do. 


0:04:53.1 MS: You're such a seven, Ella. 


0:04:55.4 EC: Yeah. I am a seven. 




0:05:00.2 MS: So, we know, of course, skin has a pH of 4-6, or doesn't. 


0:05:04.0 EC: I don't know. Okay, confession, remember when we talked about big box beauty stores, and I had bought pH strips to test when my clients brought in... Brand new clients brought in their product, I was gonna be wagging my finger and going, "Mm-hmm, that's cute but this is not that pH." And especially because one brand lists their pH on their products. And I think... Oh, there is a tool that I did buy too. It didn't work because it was from Amazon but... That you can measure the pH of your skin. 


0:05:37.1 MS: Yeah. 


0:05:37.7 EC: It was like a... I buy a lot of tools that don't work but it was like something you run across to see. 


0:05:43.6 MS: Oh, interesting. To measure the pH. 


0:05:44.9 EC: To measure the pH and I know there must be a way, obviously, they have this range, but I think it would be really cool because I'm assuming that out of this range, we look at diet, we look at products, we look at hormones. But I wonder if this is gonna be something we look at in the future, is the pH, if there's not gonna be like a test for a wood's lamp. That's another testing for consultation. 


0:06:09.5 MS: I think too, the thing to remember as an aesthetician and when we're talking about skin pH also, we're focused on the surface of the skin, the stratum corneum being acidic, but as you travel deeper into the tissue and down to the dermis, that pH is changing, and also considering as well, like you said, diet and lifestyle, and your age and whether you're male or female. All of those things are gonna factor into what your pH is, and even the day of the week, your pH is going to fluctuate and the products you're using on the surface of your skin. 


0:06:42.8 EC: Do you think that's why they give a range?  


0:06:44.9 MS: Yeah, and how many of you, all you listeners out there, have had a client come in that said, "My friend had X chemical peel, she peeled like a snake, no pain, no gain. I want that same reaction." And you use that same peel on them. It's gonna be a different effect. Right?  


0:07:03.8 EC: Absolutely. 


0:07:04.5 MS: And a lot of that has to do with, of course, the state of their skin, but also pH. 


0:07:10.6 EC: 100% and I would agree. There's a lot of factors, but I think that that is absolutely a contributing one. 


0:07:13.3 MS: And then lastly, chemical peels work by temporarily reducing the pH of the skin, coagulation proteins and then inducing desquamation, that's on a very generalized scale. That's the idea behind them. 


0:07:26.9 EC: And I think when we look historically, we can go back to the 1800s is when some of the chemical peels for cosmetic reasons or for skin started becoming... I mean, we can go way back to Cleopatra, but when... As we know it, and then we look at Gessner's and when he developed the solution that he had in the 1930s and '40s. And then we look at Dr. U in the 1970s, and we can see that pH was a factor because we had single acids, single solutions or in Gessner's case, we had a perfect blend of three plus whatever. When we look at modern peels, they're not just those acids anymore. Or we look at what do we put on afterwards. So we're dropping the pH so that we can induce desquamation, but that's not where it ends with us, because we bring it back up to that 4.5 to four to sixth range too. So that's another thing. When we're visualizing this pH drop, the acid going into the skin and coagulating proteins or breaking bonds, however you wanna think about it, you have to visualize what do you want... What else do you want to have happen in there too?  


0:08:37.8 MS: Totally, I agree. So you would think that if the pH of the skin is ranging from 4 to 6, any peel under a pH of four should effectively cause exfoliation. Right?  


0:08:52.0 EC: Well, I mean, if you were basic. [laughter] If you took it down to the basics, but it's not always right. Right?  


0:09:00.1 MS: Yeah. Yeah, not that simple, right? So let's still look at some other factors that can affect the effectiveness of chemical peeling. 


0:09:08.0 EC: Let's do it. 


0:09:08.3 MS: Let's do it. 


0:09:10.5 EC: Hold that thought. We'll be right back. 


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0:09:58.5 EC: Okay, here we go. Let's get back to the podcast. 


0:10:00.6 MS: All right, so what about pKa? So this is gonna get real Scientific here, but worth mentioning, pKa is a number that shows how acidic a substance is. So we talked about pH, that's stating if a product is acidic or basic, pKa is showing how acidic a substance is. So the lower the value of pKa, the stronger the acid is. The higher the pKa, the weaker the acid is. So a very, very strong acid will have a pKa close to zero. 


0:10:35.3 EC: Okay, let's do an analogy here. 


0:10:37.0 MS: Okay. 


0:10:37.1 EC: So an analogy would be grape juice or wine. 


0:10:40.5 MS: Okay. 


0:10:41.0 EC: Okay?  


0:10:41.5 MS: Yeah. 


0:10:41.8 EC: So PH, pKa. So is it an acid or not? And then we'll see. Grape juice and wine, pKa would be wine, let's just say. And then from there, what is the... I mean, I'm assuming a lot of people are familiar with their alcohol by volume or whatever, but how much alcohol is in that wine, or how much alcohol... What's the proof of this vodka, for example? So that's not to say anybody should drink, but I'm just saying that's a good comparison when you're looking at pKa. 


0:11:10.3 MS: Cool, I like it. So what about pKa as it relates to pH? So pKa values, they're fixed and constant for every molecule, it never changes, no matter what the concentration of the molecule in a solution is, that kind of goes back to your analogy there. So no matter what the pH of a solution is, and pH can fluctuate, we'll talk about that in a second with buffers. The pKa stays constant. So although this is often looked, and I think even by manufacturers and marketing language and even estheticians, I know as estheticians, even dermatologists, I don't think focus on this number. This has significant relevance because it informs the professional using their chemical peel the pH that is required for an effective peeling outcome. So that's really interesting. So for an example, an acid with a higher pH than pKa indicates that the peel solution will have more salt, in other words, be more neutral than the acid. Salt adds no value to your chemical peel experience, it's not gonna give a positive outcome. 


0:12:14.1 EC: Okay, I've got a story here. Do you remember probably 15 years ago, maybe a little bit longer that... I don't know if I should say the name, but a chain of department stores, high-end department stores in the cosmetic department had a 70% glycolic acid solution. So they were these take-home kits. 


0:12:37.3 MS: Yes. 


0:12:37.8 EC: And that's not uncommon. This is just the first time I remember seeing this, and I remember it was back when I was not super confident with my peels yet, learning. And I thought, "How can that be possible?" Because remember, I was taught percentages and pH, so I was so confused, how can we be confined as professionals to this... I think at the time it was 30% or 35%, but XY big box store can sell the 70%. And the difference here is exactly what you're talking about, is that there was a percentage, which is another factor, and a standard pH, but the pKa pH balance was different. 


0:13:20.8 MS: Yeah, yeah, really interesting. And I think even as a professional working with Prolines, I have seen trends where chemical peels have come... Become available, come on the market for professionals, and it has been marketed as a chemical peel that is highly effective but will not "make you peel". So again, talking about this balance between pKa and pH as well as whether or not that chemical peel is buffered. 


0:13:50.9 EC: Yes. 


0:13:51.6 MS: So that's another factor we're going to address here. And so when the natural pH level of a solution is changed, that's called buffering, and pH is something that chemists or labs can alter, whereas again, pKa, going back to that is something that is constant for that molecule, it does not change. So buffering can either increase or decrease the pH when mixing ingredients, buffered and non-buffered products, they carry the same percentage of an active ingredient. So for instance, this 70% glycolic may have a very high pH and not give an aggressive outcome to the surface of the skin. 


0:14:32.9 EC: While we're on this subject, something to keep in mind is that desquamation that we talked about earlier, the amount of peeling, and we've said this before, that peels is a category that I think we lump into from early technology, for lack of better term, but from the 70s, 80s when we first started using a lot of cosmetic peeling, but not necessarily do peels equal results. So though pKa is probably something as an aesthetician, you won't hear from the manufacturers, it's important to understand that it's okay that you're still getting results, there's still an opportunity, not every... Not every company will give the results, but there's still an opportunity for results without cheating. 


0:15:19.1 MS: Yeah. Oh, totally, yeah. So just to drive this home with buffered versus non-buffered. When an acid is buffered, it means that some of that acid has been converted to salt. And we talked about that earlier in the podcast. Salt is bringing this more to a base or neutral, so that's why you're getting those peels where like you're saying, Ella, you're not having that shedding and getting that exfoliation property or dropping the pH of the skin to get a really deep exfoliation. 


0:15:49.8 EC: And you can... There's opportunities to buffer in your treatment room, whether you're adding a mask or the way you apply, are you prepping the skin with... It may not be buffering the actual solution, but if you're preparing the skin with hydrating versus something drying, the peel is gonna attach in a different way. 


0:16:11.8 MS: I love that. 


0:16:12.6 EC: It's gonna travel a lot deeper. 


0:16:13.0 MS: Yes, so good. 


0:16:15.0 EC: So keep that in mind as well. So I think there's a lot of... Peeling, it's still funny. Yesterday, this Laser rep came into my shop and I pretended like I was a receptionist [laughter] because I was at the front, and I'm like, "Oh no, she's not in, she's very busy." And he's like, oh. 'Cause they come in all the time. He said, "Oh, did she do anything? What did she do?" I said, "Oh, chemical peels. Just peels. That's about it." "Oh, did she do devices?" And, "Oh no, no, no, just peels." It was really fun, but chemical peels for me are so fun because of the way you can manipulate the skin and not only once a year or twice a year, they're ongoing. And again, they're all lumped into that term, chemical peel. But each time a client comes in is when we're deciding what do they need that day, how low do they need to go? So that influences how we're gonna prep, what they're gonna use at home, what are we following up for, am I gonna use a device post or not? Like an LED, for example, or Cryo or different kind of device opportunity. So it's really, really, really fun. 


0:17:18.4 MS: You make such a good point about affecting how that peel or manipulating how that peel affects the skin pre and post peel. 


0:17:27.2 EC: Absolutely, there's other ways to manipulate, while we're on the subject of peels, but the application, after you've prepped the skin, however you're prepping it in treatment room, whether you're doing an alcohol prep or hydration prep or clay mask prep. Because that's a whole different experience too, 'cause it draws out all the oils of the skin, so the skin... Totally, totally different adherence. But if you have these viscous-based peels and you use massage, if you massage them in different areas, this is a fantastic way to... The skin is not always even, so if you have somewhere you want a little bit more action, a little bit more response, you can massage it in that area and get an amazing result. The other thing is, are you using gauze versus like a cotton round, you're gonna have a completely different response. 


0:18:16.5 MS: Or a mask brush even. 


0:18:19.1 EC: Or a silicon mask brush or the orange ones. I've read... They're called recons or something. Those are gonna give two different results. Or we learned glycolic swabs, but they're the big Q-tips. 


0:18:31.2 MS: Yeah, round swabs. 


0:18:33.7 EC: Round swabs. So those all give different results, you can have the same peel solution, different applicators and have different responses in the skin, so. 


0:18:40.6 MS: Yeah, so true. 


0:18:41.7 EC: So true. I'm not sure if it changes pH or not, but I guess it would. 


0:18:47.6 MS: Yeah, well, how deep you're driving that peel, I think is dependent on the applicator. 


0:18:50.8 EC: How low can you go?  


0:18:53.3 MS: Now, listeners, we wanna hear from you, share with us your chemical peel experiences, what factor do you think is most important when it comes to peel outcome, share your thoughts with us on social media by commenting on our Instagram or Facebook posts or via email and get connected at ascpskincare.com. Thank you for listening to ASCP Esty Talk and for more information on this episode, or for ways to connect with Ella and myself or to learn more about ASCP, check out the show notes. 



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