REVIEW: The Ordinary EUK 134 0.1% - The Moisturizer
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REVIEW: The Ordinary EUK 134 0.1%

Cabecera The Ordinary - REVIEW: The Ordinary EUK 134 0,1%
The Ordinary EUK 134 0.1% is an amazing serum. Including this antioxidant in your morning skincare routine will prevent the damage caused by free radicals, which are responsible of our skin’s premature aging. Do you want to know how to use this serum, where to buy it and how effective it is? Check my review!


Hello! Today I am very happy to present you with my first review of a product from The Ordinary. It’s been a while since I wanted to tell you about my experience with the EUK 134 0.1% by The Ordinary, the most economic brand of DECIEM. This serum seems to me a great way to give my skin extra nutrition without much effort, so soon I will tell you about more. Let’s go!

PRODUCT: EUK 134 0.1%

You can get the serum The Ordinary EUK 134 0.1% on DECIEM (recommended) and on SkinStore.

The Ordinary - REVIEW: The Ordinary EUK 134 0,1%

After getting started in the world of serums (specific complementary treatments) I wanted to try something from The Ordinary, a brand with quite a reputation. The Ordinary, belonging to the DECIEM group, has become an iconic skincare brand. Throughout this year, the company was involved in a major image crisis that led to an important stoppage of its commercial activity and rumors of final closure. Recently, after all the drama, which ended with the dismissal of the previous CEO and founder (Brandon Truaxe), the company has resumed its activity (in part thanks to the momentum provided by Estee Lauder after acquiring 28% of DECIEM) and they are returning to normally distribute products.

After catching up with the soap opera, we’re going to the really interesting thing: the review. This product specifically stands out for protecting the antioxidants that normally exist in the skin from external agents that damage them and make us unprotected against radiation, cold, contamination, etc. The EUK 134 is a very powerful molecule, so it is usual to find concentrations lower than that offered by this The Ordinary serum. You can read my article on antioxidants here, so if you want to start using them to boost the effectiveness of your sunscreen you should take a look at it!

I have spoken very happily of serums, but what are they? In summary, they are products that give your skin that extra you may need and that your usual beauty routine does not provide. Most of the serum that I have tried so far are focused on providing the skin with compounds with antioxidant, anti-aging or brightening properties. Thus, when applied right after the serum and before the moisturizer your skin is well fed . Of course, each of these products is different and provides different properties to your skin, so the magic lies in combining them properly, according to your needs, to get the best possible result.

So, what makes this product so interesting? It’s simple: antioxidants help your skin fight free radicals. If you let free radicals roam through your skin, they damage elastin and collagen, so antioxidants help your skin stay young and healthy.

The Ordinary - REVIEW: The Ordinary EUK 134 0,1%

When I used it for the first time I had to check several times the products that I would combine with it, because the box expressly states that it can not be combined with very acidic treatments (such as ascorbic acid suspensions), since they make the EUK 134 lose all effectiveness. Maybe this point made me hesitate several times before I started using it. Once I lost my fear I incorporated it into my morning routines and I use it a couple of times a week (in fact it is recommended to combine it with other treatments to increase its antioxidant capacity).

When opening the package we can see a liquid product, copper colored and odorless. Its texture is very light and not oily. Once spread (I do it after a water-based serum like this one) I like to let it be completely absorbed before applying the moisturizer. It absorbs very quickly and leaves me with the sensation of greatly moisturizing the skin. During the rest of the day I look better, I do not know if it will be a matter of the results it gives or if it is self-love, but I assure you that it shows.

It is worth mentioning that it does not include water among its ingredients. The EUK 134 fights free radicals (providing antioxidant effects) and prevents the loss of water and oxygen from the skin. In addition, it reduces redness and protects against ultraviolet radiation. This product does not contain fragrances.

The packaging is very similar to the others of this brand, taking great care of the aesthetic. The cardboard box is simple and minimalist, in black and white. The bottle is made of dark glass, to protect the product from ultraviolet radiation. The applicator is dropper type.

I liked the experience of getting started on The Ordinary products. I believe that providing extra nutrition to my skin will be positive to better combat the effects of pollution (which is everywhere in Barcelona), cold and radiation. In addition, by providing support for the skin’s natural antioxidants, they degrade more slowly, thus fighting aging. At the moment I still have a lot to learn about these types of treatments, but I think they are an excellent measure to give extra help to our skin. Soon you can read new reviews about other serums.



After washing and toning the face, this product can be used after a water-based serum or even by skipping that step, right before the moisturizer. I do use the serum before applying it and let it work and absorb for a minute. It can not be used with other highly acidic products, such as those containing glycolic acid or vitamin C.

This graphic aims to help you understand in which part of your skincare routine you should use each product.
You don’t need to do all the steps from this routine (but you should always cleanse, moisturize and use sunscreen).
Remember it’s key to do a patch test every time you consider adding new products to your skincare routine.



Propanediol, Ethylbisiminomethylguaiacol Manganese Chloride.

You can get the serum The Ordinary EUK 134 0.1% on DECIEM (recommended) and on SkinStore.

What do you think of The Ordinary serums? What is your favorite? Soon I will continue posting posts about other serums with different properties, if you want me to talk about one in particular do not hesitate to leave me a comment.


If you liked this post, you will be interested in reading:

Do you want to learn to take better care of your skin? You can see an index of all my informative posts here

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The Moisturizer

I’m Nacho and I’m passionate about skincare. I really enjoy learning and sharing my knowledge about skincare and I read scientific papers so you don’t have to. I want to break stereotypes because I believe skincare has no gender: skin is skin.  


    • Nacho · The Moisturizer

      Hi Sara!

      As I explain on my guide about skincare and pregnancy, it is difficult to assess whether a particular product is safe to be used in those cases, as cosmetics aren’t usually tested on pregnant or nursing mothers, since the potential risks of those studies are higher than the potential benefit of that evaluation. I’d advise you to ask your GP or dermatologist, since they will be able to provide you with more precise information on the topic.

      Just so you know, you can check this index of all my informative posts, I’m sure you will find it helpful 😉

      Remember to follow me on Instagram, Facebook, Pinterest and TikTok and to like, comment and share my posts so that I can help more people take care of their skin 🖤

      Have a great day,

  1. Lee

    Hi Nacho

    There are 3 ordinary products that I like: alpha arbutin 2%+HA , retinol .2% and EUK 134. In what order should I use them? Thanks

  2. Oona

    I’m confused, can EUK 134 0.1% be used at the same time as a retinol? I have found conflicting information on the web.
    I currently use Olay Regenerist Retinol 24 Night Serum Fragrance Free, which is a lotion/cream so I’m not sure which order it should be in as well.

    The EUK bottle says you can mix it with other treatments to enhance their anti-oxidant capacity significantly, so could I do this with my Natural Moisturizing Factors + HA or CeraVe Facial Moisturising Lotion PM, or TO Niacinamide +10% Zinc?

    Thanks 🙂

    • Nacho · The Moisturizer

      Hi Juliana! 😊

      There’s no need to keep it in the fridge. As a general rule, as long as the brand doesn’t state the product must be stored at a particular temperature or in the fridge, keeping it at room temperature is what’s best for its preservation.

      Have a great day,

  3. erha

    Hello Nacho.
    I’m really interested in EUK 134 because they said it is a superb antioxidant that can multitask, regenerate itself and ward off UV. I can see it could replace Vit C in Day time usage.
    But that’s where my confusion emerge.
    As we all know that Vit C is essential, and replacing it with EUK 134 will make us take Vit C at night time. Which is very good actually.
    But with vit C in night time, when should we use our Niacinamide and Retinol?
    Shall we give up our Night time’s Niacinamide and Retinol in order Vitamin C make its way ?
    Is it that worth it to take EUK and alter our day-night regimen significantly??

    • Nacho · The Moisturizer

      Hi Erha, welcome! 😊

      I love your questions, they’re such interesting thoughts! On my post about how to create a skincare routine I talk a bit about combining different actives, I think you’ll find some useful tips there.

      Regarding your particular concern, there are different strategies you could implement depending on the particular products you use and your skincare needs, such as using EUK-134 and vitamin C on alternate mornings, using a stronger vitamin C product or retinoid on alternate PM routines, etc. In my opinion, the best routine is the one you can properly adapt to and the one you actually do, so I hope these tips help solve your question! 😉

      Have a great day,

  4. Sola

    Hello Nacho!

    Quick question: can Euk134 be used with stearic acid? Can it be used with bakuchiol?

    Thanks so much!

    • Nacho · The Moisturizer

      Hi Sola, welcome to my blog! 😊

      Generally speaking, you mustn’t use EUK 134 along with strong acids (such as AHAs or BHA). I’m not sure about the particular cases of stearic acid and bakuchiol, so I would advise you to ask the brand directly so that they can give you a more accurate insight on the topic 😉

      Have a lovely day,

  5. Valeria Ojeda

    Hi Nacho I would like to purchase The Ordinary products for my hands, they are very wrinkle and dry, my skin can tolerate well strong skin care and treatments at least on my face but I don’t know which ones of this serums would help for my hands, Do you have a suggestion? Thanks

    • Nacho · The Moisturizer

      Hi Valeria! 😊

      The first thing I’d advise you is to keep your hands well moisturized (use a deeply nourishing cream) and, of course, use a sunscreen with SPF50, like the ones you can see in this comparison.

      Besides that, you could include a more specific treatment, I think I would start with peptides (about which you can read more in this guide) and then, over time, see how your skin evolves 😉

      All the best,

  6. Teresa mesquita

    Hello, can i use the niacinamida 12%+zinc PCA 2%. Serum and then the EUK? Thank You

    • Nacho · The Moisturizer

      Hi there Teresa, welcome to my blog! 😊

      There should be no issue at combining those two serums, but remember to patch test them before including them to your routines to make sure they won’t cause you irritation 😉

      All the best,

  7. Lou Del Mundo

    Hi Nacho,

    After reading several comments and your reply to them. I am hoping you can help me too. After watching The Original products are so great in Tiktok apps. I just bought it today, but I am now hesitant to use it. I’m afraid too really. Well, here it is Is’t okay to combine EUK 134* 0.1% and the original vitamin c suspension 30% in silicone? I’m afraid that it might get worse in the face.

    I hope you read it. Thank you and keep safe.

    Lou – from Philippines

    • Nacho · The Moisturizer

      Hi there Lou, welcome to my blog! 😊

      No, you shouldn’t combine the EUK 134 and the Vitamin C Suspension 30% in Silicone, since they are not compatible. In case you want to use both products you could apply the EUK in your morning routines and the vitamin C in your evening ones 😉

      All the best,

  8. Ria

    Hi! Thank you so much for all these useful details! I’d like to ask you something too about EUK 134 . I just bought it and i am as you said a little hesitant to use it because i don’t exactly know where to put it into my routine and with which other product i can or cannot combine it.
    I bought also the Buffet serum by TO.(the old one ,the classic Buffet) .i started using ot and it’s a really wonderful product. Do you know if i can use them together-i mean during the same skin routine? And would you recommend me tonuse Euk during my pm or am routine , considering that summer is coming and I live in south greece where the sun is really intense? I’m so xonfused and enthusiastic the same time with these products!
    Thank you in advance! 🙂

    • Nacho · The Moisturizer

      Hi Ria, welcome to my blog! 😊

      I’m glad you’re enjoying your skincare journey and that I can help you through it! You can combine both the regular Buffet (not the only with copper peptides, though) and the EUK 134 on the same routine. In case you want to use them together you should apply the Buffet first and the EUK right after it.

      Considering that EUK 134 is an antioxidant serum I’d include it in my morning routines, that way you can indirectly boost the effectiveness of your sunscreen by preventing the damage of UV radiation on your skin 😉

      Don’t forget to patch test before including them in your routines!

      All the best,

  9. Pau Rubio

    Hola Nacho!

    Me encanta tu blog.
    Quisisera saber si este producto se puede combinar con el Advanced Night Repair
    Synchronized Recovery Complex II de Estee Lauder?

    Gracias 🙂

    • Nacho · The Moisturizer

      Hola Pau!

      Me alegro mucho de que te guste mi contenido, no dudes en compartirlo! 😊

      En este caso, aunque creo que los dos pueden combinarse sin problema, yo utilizaría el EUK por las mañanas y el serum de Estée Lauder por las noches porque así los efectos antioxidantes del EUK pueden atacar a los radicales libres y potenciar los beneficios del protector solar 😉

      Un saludo!

  10. Soumya

    Hi Nacho!

    It’s really sweet to see someone be so kind to explain so much. I love your blogs and you’re doing great!

  11. Mimi

    Good morning Nacho,

    Thank you for looking into the article for me. I’ll for sure have a read on the more update-to-date study by John M. Pezzuto.


    • Nacho · The Moisturizer

      Hi Mimi!

      You’re so welcome, I’m happy to help you out (especially when it comes to explaining scientific articles that may be a bit overwhelming). Feel free to ask any other questions you have anytime! 🖤

      All the best,

  12. Mimi

    Hi Nacho,

    Thanks for the information and the suggested routine. Would I need to worry about the pH of the mixture between 100% L-Ascorbic Acid Powder and my serum? I’ve applied this mixture a couple of times, 3 to 4 drops of serum to ~1/8 small spoonful of 100% L-Ascorbic Acid Powder in which the small spoon was package together. After the mixture was spread on my face, there’s no tingling or any special sensation. Should I use more than the 1/8 small spoonful?

    Also, I want to share with you an article I’ve stumbled upon a few days ago on the effect of resveratrol from This url takes you to the skincareedit page authored by Michelle Villett. Somewhere on the page in the resveratrol section, there’s a hyperlinked to the actual article. You can also go there with the following url, https/, though I find the article too scientific for my consuming. I just scrolled all the way down to the “Discussion” for the layman language. Basically, Michelle wrote that “resveratrol has been shown to have estrogenic action”.

    I’m all ready to return my resveratrol to DECEIM but thought to see what you think!

    Thanks for your help!


    • Nacho · The Moisturizer

      Hi Mimi!

      About the combination of 100% L-Ascorbic Acid Powder and your serum, since I don’t really know which serum you’re using I don’t know how they can work together. However, the combination with Resveratrol 3% + Ferulic Acid 3% is, in my opinion, the best combo with ascorbic acid. The amount you use is something you must see, you should be able to progressively increment the amount of ascorbic acid powder, but you should see how it works for you and if you feel like your skin can tolerate it or wants more of it.

      Regarding the article you mentioned on resveratrol, after carefully checking the paper from Gehm, McAndrews (…) and Jameson from 1997, they do conclude that resveratrol has been shown to have estrogenic action, but we must take into account the methodology of that study. In that case, the scientific team inoculated resveratrol directly into isolated mouse cells and found that result. However, that doesn’t mean that applying resveratrol topically (or even after ingesting it, since resveratrol is naturally found on grapes) might affect your estrogen levels. Actually, more recent studies have shown the opposite result to the one you mentioned. There’s a pretty interesting article on the overall safety of resveratrol by John M. Pezzuto from 2019, here’s the link in case you want to have a look at it.

      I hope I was able to solve your doubts and you keep on using and enjoying resveratrol without any worries 😊

      All the best,

  13. Mimi

    Hi Nacho,

    After reading your reply, I now have more questions. Is hyaluronic acid not an acid? Can I really use it with EUK 134? I do want to pair the two since I bought them together, along side with resveratrol 3%+ferulic acid 3% and 100% L-ascorbic acid powder. I am just hesitant because of the recommendation not to use acid with EUK 134.

    I’ve started using the hyaluronic acid but haven’t touched the EUK 134 because the serum I’m using has stearic acid, ascorbic acid and dehydroacetic acid in it and these 3 acids appear in the ingredient list in that order.

    Also, another serum I purchased has glycerin and something called acrylic acid copolymer in it. Isn’t glycerin an acid? Again, not sure if I can use this serum with EUK 134.

    I’m no chemist so I’m only scanning the word “acid” in the list of ingredients to determine if a certain product contains acid. Admittedly, that’s not a good way to identify acid because I’m guessing some acids don’t bear the word “acid” in their name.

    Sorry, I’m rambling! I’m very interested in establishing a AM/PM skin care routines that targets hyperpigmentation, even/brighten skin tone, and general anti-aging. I’d appreciate anything you have to suggest.

    Thanks for all your help!


    • Nacho · The Moisturizer

      Hi Mimi!

      I know that sometimes skincare gets a bit tricky (and it definitely may sound like a Chemistry class). Here’s a link to my guide on acids, I recommend you to read it thoroughly so that you can understand what I mean when I speak about acids (and how hyaluronic acid, even if it has the word ‘acid’ in its name, isn’t really one).
      Considering the products you mentioned, I would combine them like this:
      AM: Hyaluronic Acid + EUK 134
      PM: Resveratrol 3% + Ferulic Acid 3% + 100% L-Ascorbic Acid Powder or the other serum you mentioned.
      Regarding the ascorbic acid powder, remember this is a very strong product, so if your skin isn’t used to vitamin C (which, after all, is an acid), you should take it easy and add it to your routines progressively so that your skin can get tolerance. Here’s a guide I published on vitamin C, I strongly recommend you to take a look at it too.

      Thank you for participating!
      All the best,

  14. MiMi

    I have a question…
    I’ve purchased the ordinary EUK 134 and am finding it difficult to incorporate it into my skin care routine because it’s not supposed to used with other acidic products.

    Can you define “highly acidic products” in “It cannot be used with other highly acidic products, such as those contain glycolic acid or vitamin C”? I’ve read the ingredients of the serum I’m using as well as other serums on store shelves, most of them contains different types acids. So am I suppose to use EUK 134 as a serum alone before moisturizer?

    • Nacho · The Moisturizer

      Hi Mimi!

      Welcome to my blog! It’s a pleasure to find other people who share my interest and love for skincare and beauty 😊
      When I mention highly acidic products I mainly mean suspensions of ascorbic acid (such as this one) and other acid suspensions, such as the Azelaic Acid Suspension 10%. Also, it shouldn’t be mixed together with retinoids or solutions of acids (although they can go along the same routine as long as it’s in different steps).
      Generally speaking, I prefer not to combine EUK with those acidic products, since EUK 134 is quite unstable and I prefer to go the extra safe way. When I use EUK 134, I normally use it in my AM routines after a hyaluronic acid serum (like this one).
      Check my guide on using acids in your skincare routine if you want to keep on learning about them 😊

      If you have any other questions about product combinations just let me know, I hope I helped you! 😉

      All the best,

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