





Before we start, I just want to add a note about what I expect out of these types of toners. My expectations are pretty low, actually:

I expect them to be a suitable pH to lower my skin's pH after cleansing to prepare it for my actives (Vit C, BHA, and AHA), I expect them not to leave residue on the skin that would interfere with the ability of my actives to work directly in my skin, I expect them to be non-irritating.

That's all I need. With such minimal expectations (I pay no need to the brand's claims such as "prevents whiteheads, blackheads, and blemishes with the perfect blend of all-natural ingredients and mineral water to rejuvenate and replenish your skin." Yeah, no. It's a just a pH-adjusting toner. Its job is to ready my skin for my next steps, I'm not expecting magic here. Most people don't even need a pH adjusting toner, I just live in the desert so my skin dries out too fast to wait around for it to naturally adjust itself. But I do, and it does, so here I am. Onward!





In this post:

Ingredients overview of Cosrx vs Mizon

A small pH testing snafu and ensuing rage-shopping

pH of Cosrx Natural BHA Skin Returning A-Sol

pH of Mizon 8% AHA Peeling Serum (control) and AHA BHA Daily Clean Toner

pH of Cosrx AHA/BHA Clarifying Treatment Toner

My observations and experience with Cosrx vs Mizon

I'm also incredibly surly today because I realized halfway through my prep, when it was too late to stop, that I had ordered the wrong size of test tubes. RAGE!



Ingredients overview of Cosrx vs Mizon





Let me start by saying I was really looking forward to trying out the Cosrx AHA BHA toner, because I absolutely love the Cosrx BHA Blackhead Power Liquid, and I am reasonably satisfied with the Cosrx Natural BHA Skin Returning A-Sol spot treatment.





I have repurchased 5 bottles of Mizon's AHA BHA toner (to date) and obviously I am very happy with it, but it is constantly selling out and is hard to find, whereas Cosrx products have been pretty easy to source so far. Would the Cosrx be a dupe of the Mizon? I hoped so!





Even more encouraging was the ingredients breakdown between them, with Cosrx seeing to be the clear winner:





Cosrx Mizon Mineral Water Water Salix Alba (Willow) Bark Water Butylene Glycol Pyrus Malus (Apple) Fruit Water Alcohol Butylene Glycol Glycerin 1,2-Hexanediol Carica Papaya Fruit Extract Sodium Lactate Portulaca Oleracea Extract Glycolic Acid Arnica Montana Flower Extract Water Artemisia Absinthium Extract Betaine Salicylate Achillea Millefolium Extract Allantoin Gentiana Lutea Root Extract Panthenol Glycolic Acid Ethyl Hexanediol PEG-60 Hydrogenated Castor Oil Lactic Acid Sodium Lactate Salicylic Acid Disodium EDTA Methylparaben Propylparaben Fragrance









I notice that the Mizon has moisturizers listed much earlier than Cosrx, although it does contain alcohol which the Cosrx dos not. I would have thought that would mean the Mizon would be less irritating, but I'm getting ahead of myself.





Let's get pH testing!





A small pH testing snafu and ensuing rage-shopping





pH strips can react oddly with acids and give inaccurate readings. I do still use pH strips for general products, especially things with a lot of lipids, like creams and emulsions. You can learn more about my kit here: I use a digital pH meter with a two-point calibration for pH testing acids, as. I do still use pH strips for general products, especially things with a lot of lipids, like creams and emulsions. You can learn more about my kit here: Better Beauty Through Chemistry: Unboxing of my digital pH Meter supplies





As I grumbled about in that post, I was unhappy with not having a suitably long-and-narrow glass container that would allow me to sacrifice minimal product yet still completely immerse the electrode of the digital meter. I was unimpressed with my DIY emergency solution to use wine glasses, and thought I'd be all smart and get test tubes off Amazon. Designed for the purpose and all, amirite?





Well, due to the weather delays in shipping, I received them just in the nick of time for this post and when I unwrapped them, my relief turned to disbelief, despair, and then rage very quickly.





Buffer liquid of pH 7.01 and buffer liquid of pH 10.01 pictured at far right. As you can see in the image, the test tubes are approximately twice the height my meter needs in order to reach the liquid at the bottom. As you can see in the image, the test tubes are approximately twice the height my meter needs in order to reach the liquid at the bottom.





asdfjhkjhlhg%$&%#@!!!





I am not about to waste an entire bottle of product to bring the surface of the liquid up to a level that the pH meter needs, so I said a bunch of really foul words that made my husband flee to his gaming computer (with headset) and angrily stormed onto Amazon to find 75mm test tubes. I would have realized that's what I needed in the first place if I had not been too lazy to dig my digital meter out of storage and measure the darn thing.





Did you know you can buy wine on Amazon? Amazing the versatility it has. Anyway, back to testing with my wine glasses 'shabby chic' method.





pH of Cosrx Natural BHA Skin Returning A-Sol

pH result: 4.32

That wineglass. Ugh. ANYWAY, this test result is quite interesting because I have been asked (and have been wondering myself) where exactly this product goes in one's routine order.

The order of your products is pretty important when you're working with pH dependent products like actives. You can read more here: Putting your products in order, including pH dependent acids

As I explain in that post, normally BHA goes before AHA, due to it requiring a lower pH to be effective (below 4.2) and also because it's oil-soluble and does a great job of clearing out your pores so your AHA product has a clear shot at your skin afterward. However, the A-Sol is neither high enough in concentration (according to the back, it's only 0.5% ) nor low enough pH for exfoliation.

That doesn't mean that it's not going to help your skin, as BHAs do have other benefits even at a higher pH, but it does mean that it needs to shuffle to the back of the line and go on after you are done all your other actives. I still like to give it a bit of a wait time to work on my skin before I add any layers, though.

pH of Mizon 8% AHA Peeling Serum (control) and AHA BHA Daily Clean Toner

pH result: 3.83



I have tested this product before, in the I have tested this product before, in the Better Beauty Through Chemistry: Unboxing of my digital pH Meter supplies post, but I am testing it again today for a few reasons.

One, I want to show how consistently the Mizon AHA serum tests (this is my 5th bottle, and all have tested in the same range), and also to provide a relative ph result to compare the others to. 3.83 is definitely firmly in the 'exfoliation' range, as 4.5 is the high end for AHAs.

I also am testing this instead of the Mizon AHA BHA toner, because as you can see from the first picture on this post, I am dangerously low and could not afford to waste the product. However, I do have pictures of its test results in the link above, which came out to 4.30 for the Mizon Toner.

Just let that sink in for a second, if you would ... the Mizon AHA BHA toner is 4.30, and natural skin pH is between 4.2 and 5.6 [The Mizon 8% AHA Peeling Serum is between 3.83 and 3.89, but it is also a serious exfoliant that I don't use daily. Ready for the Cosrx toner result, by comparison? , if you would ... the, and natural skin pH is between 4.2 and 5.6 [ source and more info here ]., but it is also a serious exfoliant that I don't use daily. Ready for the Cosrx toner result, by comparison?

pH of Cosrx AHA/BHA Clarifying Treatment Toner

pH result: 3.85

Say what.



And thus the great mystery of why my skin was reacting to this toner is solved, at least this is the most plausible explanation in the absence of any other explicable factors. I'll get into this more below.



I have no idea why this 'toner' has such a low pH, because it's really completely unnecessarily for a 'prepping' step be right down-n-dirty in the exfoliating pH range. Also, this product has low concentrations of both BHA and AHA, so it's not even packing much exfoliation ammo to begin with, so why have such a low pH? It makes no sense to me, and it's overkill for what pH-adjusting toners are supposed to do ... aka, adjust the pH of the skin after cleansing, in preparation for pH-dependent products, without irritating the skin.

My observations and experience with Cosrx vs Mizon





my head tried to convince my skin that it was really ok:

"No honest, it's really better than the Mizon, look at the ingredients list!" "But it's so easy to source and it's so cheap!" "Look, it comes in a handy spray bottle!" Yeah, no. Somehow, the Cosrx Toner is very irritating to my skin, and my skin loves acids. Looooves them! I tested this product, despite the burning face effect, for a whole week, trying every application method I could think of. I applied it with a cotton pad



Nope.



I tested it on the left side of my face, with the Mizon as a control on the right side of my face. From the very first application, I could feel that my left side felt hot and irritated, whereas the Mizon side was happy as usual. The sensation persisted all day, which is also uncommon for me. I figured it was the application method, but even as I switched it around in ensuing applications, the result was always the same. The Cosrx side persisted in having an irritated sensation.



I even tried patch testing it on the Mizon side, just to make sure it wasn't some sort of inexplicable effect on only the left side (was I sleeping on my left side all of a sudden?) but nope. Same effect.



This is super disappointing to me because I expected something with 1. no alcohol, and 2, fewer ingredients to be gentler, safer on the skin, and of course less irritating. What the heck, Cosrx?!



I did pH test it with my strips but got a really confounding result, so I decided to hold off until I could set up and calibrate the digital pH meter, and when I finally pH tested everything today, it made more sense. 3.80 is sort of unnecessarily low, and therefore potentially irritating, for a product that doesn't contain enough concentration of acids to function as a 'true' exfoliant. There is nothing wrong with something being sub-pH 4, it's just strange that it is that low when it doesn't actually do anything.







Moreover, if it's not meant to be an exfoliator, why bother with a super low pH, that dips below the 4.2 threshold?



Of course my immediate thought was that I must be reacting to something in the product, but there are no flags in the ingredients for me, so I have to conclude it must be the pH. I'm not convinced that the pH is the reason for the irritation, but I know others have had the same experience, so there's something up with it. In the face of a total lack of anything else I can come up with to cause the irritation, I'm reluctantly going to conclude it might be the pH because there's nothing else I can think of that would cause it.



All in all, this was a huge disappointment and as you can see from the image, I'm back to my dire need to find either a replacement for the Mizon or somewhere that stocks it so I can repurchase it. Obviously, it's possible that my bottle was a one-off defect of some kind and it might work perfectly for you, but it's definitely not something that I will be recommending to anyone.



Update: After being 'confirmed' discontinued by an official Mizon distributor, it's now available again, and I'm thrilled. Where to get the Mizon toner: Amazon Prime for $20 | eBay for $18 | Testerkorea for $25 |



Now I've got to figure out if there's a way for me to dilute it without playing pH roulette (it's not as straightforward as 'add pH 7 water to pH 3 liquid and get pH 5!', for example) or whether I just need to banish it to my drawer of duds and never speak of it again. Yep, it's going to be the latter. Goodbye, Cosrx AHA / BHA Clarifying Treatment Toner, we shall not meet again.



Ah well, you can't win 'em all!

-Cat





** Disclaimer: All products reviewed/mentioned in my blog, are 100% purchased with my own money, with a single exception of a press sample I tested & reviewed in 2015 which swore me off of them forever. This blog contains both affiliate and non-affiliate links, and clicking the former before you shop means that this blog may receive a small commission to assist in this blog supporting itself. Please see my Contact Info & Disclaimer policy for more information. As you've probably guessed, I'm really not happy with the Cosrx AHA BHA Clarifying Treatment Toner. It's one of those products whereYeah, no. Somehow, the Cosrx Toner is very irritating to my skin, and my skinacids.them! I tested this product, despite the burning face effect, for a whole week, trying every application method I could think of. I applied it with a cotton pad as Cosrx's website directs , I tried spraying it onto my hands and then patted onto my skin like I do with the Mizon, I even sprayed directly onto my face with enough distance that it was a fine mist.Nope.I tested it on the left side of my face, with the Mizon as a control on the right side of my face. From the very first application, I could feel that my left side felt hot and irritated, whereas the Mizon side was happy as usual. The sensation persisted all day, which is also uncommon for me. I figured it was the application method, but even as I switched it around in ensuing applications, the result was always the same. The Cosrx side persisted in having an irritated sensation.I even tried patch testing it on the Mizon side, just to make sure it wasn't some sort of inexplicable effect on only the left side (was I sleeping on my left side all of a sudden?) but nope. Same effect.. What the heck, Cosrx?!I did pH test it with my strips but got a really confounding result, so I decided to hold off until I could set up and calibrate the digital pH meter, and when I finally pH tested everything today, it made more sense. 3.80 is sort of unnecessarily low, and therefore potentially irritating,. There is nothing wrong with something being sub-pH 4, it's just strange that it is that low when it doesn't actuallyanything.As you can see in the close-up of the label, it contains only 0.1% AHA and 0.1% BHA, which is hardly enough to justify it as its own independent exfoliator.Moreover, if it's not meant to be an exfoliator, why bother with a super low pH, that dips below the 4.2 threshold?Of course my immediate thought was that I must be reacting to something in the product, but there are no flags in the ingredients for me, so I have to conclude it must be the pH. I'm not convinced that the pH is the reason for the irritation, but I know others have had the same experience, so there's something up with it. In the face of a total lack of anything else I can come up with to cause the irritation, I'm reluctantly going to conclude it might be the pH because there's nothing else I can think of that would cause it.All in all, this was a huge disappointment and as you can see from the image, I'm back to my dire need to find either a replacement for the Mizon or somewhere that stocks it so I can repurchase it. Obviously, it's possible that my bottle was a one-off defect of some kind and it might work perfectly for you, but it's definitely not something that I will be recommending to anyone.Now I've got to figure out if there's a way for me to dilute it without playing pH roulette (it's not as straightforward as 'add pH 7 water to pH 3 liquid and get pH 5!', for example) or whether I just need to banish it to my drawer of duds and never speak of it again. Yep, it's going to be the latter. Goodbye, Cosrx AHA / BHA Clarifying Treatment Toner, we shall not meet again.Ah well, you can't win 'em all!-Cat

This week I'm going to be doing a mini-review of theand comparing it to my trusty. Why a mini-review, and not a full review, you might ask? You'll see shortly.