Is the Round Lab SPF better than Skin1004 Sun Serum?

If you ask any American what are the most popular Korean sunscreens, they’d probably list out Skin1004 Water Fit Sun Serum (SPF 50), Isntree Hyaluronic Acid Watery Sun Gel (SPF 50), and Round Lab Birch Juice SPF 50. And they’re all popular for a reason: they use filters not available in the US.

But within that listing, what’s the best Korean sunscreen for you?

In this blog, I’ll share my thoughts on how the various SPF compare to each other (from my perspective and wear tests).

What’s the Hype

We all think about sunscreen being thick, gloopy, and sometimes smelly. It does not get a great reputation, but it is one of the most effective forms of protection against aging and skin cancer. So there’s a clear reason to wear it. But how do we make it attractive to wear?

American sunscreens are lacking

Honestly, I am more of a fan of Asian and European sunscreens than US-based ones. In the US, the only one that I have consistently enjoyed using is the Summer Fridays ShadeDrops SPF 30. And that’s one of the problems: it’s only SPF 30. The other problem? It’s mineral-based (zinc oxide), so it won’t work for all skin tones (side note: it does work really well for me though).

Korean sunscreens offer lighter textures

Generally speaking, K-beauty SPF will be lighter, leave no (or at least less) white cast, and work to improve the skin health. And no, I’m not saying Korean SPF is the only SPF capable of that. I know there are plenty of amazing Japanese ones, as well as French ones! However, Korean sunscreens have taken the main stage when you think of amazing sun protection.

Who are Korean sunscreens for? Everyone! Generally speaking, the skin type that these SPFs work for is pretty universal. I have combo-oily skin, and I have not had any issues with the sun protection I’ve tried thus far. Plus, because they are much more sheer (or transparent), they work for a wider range of skin tone depth.

And all of these sunscreens are pretty much the same price range ($9-17), which makes them more affordable than your favorite Sephora SPF.

My Non-Comprehensive Korean SPF Ranking:

Let’s get into how each of these sun products rank compared to each other. Please keep in mind that this is based on my experience of these products over the years, and everyone has different skin/allergies/etc so your personal experience may vary. Or it may be theliteral same!

  1. Skin1004 Water-Fit Sun Serum SPF 50

    This is going to come as a surprise to absolutely nobody, but my favorite from the list is the Skin1004 one. From the packaging to the product, I am a big fan. Here are my top 3 reasons why I liked it:

    1. Excellent packaging

      At first, I was ambivalent about the packaging. I liked the squeeze tip of it, but I was worried that getting the last bits of product would be a nightmare. However, as I continued using it, it created a vacuum and actually got a shocking amount of product out. When I eventually cut the tube open, there was still some product, but not nearly as much as I had anticipated.

      And using the actual pump is a very convenient application method as well. It doesn’t dispense too much, and I can easily “measure” it out across my finger length.

    2. Skin improvement

      This one is fully personal experience, so take it for whatever it’s worth. But I noticed that when I switched from an American SPF (unnamed brand to keep it not messy haha) to this SPF, my skin started getting much smoother and I noticed it looking bouncier. And interestingly, my pores looked smaller too. And that last bit is something that I only really noticed with mineral sunscreens because they kind of act like a skin tint in certain situations.

      So it was very refreshing to see such positive skin results from a sun protection product!

      There are a lot of botanical extracts (which could be why my skin was improving), glycerin for hydration, and adenosine. It was very refreshing to get all of these extra skincare benefits from a product that is just going on as the last step in my routine.

    3. almost-nothing finish

      Of the three sunscreens in this list, I would say that this is the lightest. It really does feel like you are wearing nothing on your skin, which is perfect for me (someone who has an 11-step routine). But that also means it is perfect for the people who hate wearing any amount of sunscreen. It will not only give them the opportunity to get sun protection, but it will make it a pleasure to use!

  2. Isntree Hyaluronic Acid Watery Sun Gel SPF 50

    My second pick has to be the Isntree Watery SPF 50 (note: I have not tried the onion one—not because I hate onions, but I just haven’t gotten a chance yet!). While it is a great option and has a lot of similar properties to the Skin1004 one, here are where they differ:

    1. Standard tube packaging

      Compared to the Skin1004 one, this packaging is much more of your traditional tube. However, it is a flatter tube than your normal one.

      So it doesn’t get that same vacuum creation I saw with the Skin 1004, but it had a pretty light texture to it that did facilitate getting a decent amount of product out of the tube before I had to cut it open.

    2. More shiny finish

      Compared to the Skin1004 one (which has a more natural/slightly dewy finish), the finish is slightly more on the dewy side. And that works for some people, but I think for me, it is not my favorite.

      But the dewiness is not a dealbreaker for this product. It is definitely in the manageable range in my experience. So I can still use my makeup or setting spray on top of it and I am good for the day.

    3. Isntree has better ingredients

      It might sound contradictory because I just said that the Skin1004 product made my skin look better. But on paper, the Isntree SPF has better ingredients than that one. For me, I don’t place as much emphasis on a variety of botanical/plant extracts because while I do think they have a solid benefit, it is hard to know exactly what is in the extract and what it is doing for you (unless the brand shares what the benefits are — presumably because the ingredient supplier has told them).

      But for the Isntree SPF, it has great ingredients like ceramides, centella, glycerin, and various types of hyaluronic acid. To me, those ingredients are much more in line with improving my skin (over time) than the Skin1004 ones. So I was a little shocked that I didn’t see a skin improvement. But that’s a testament to how ingredient lists don’t always equate to a better product.

  3. Round Lab Birch Juice SPF 50

    This was the last one I tried out of all the popular SPFs. And unfortunately, this Round Lab one wasn’t as perfect for me as the others… I had high hopes because I know so many people who use this as their holy grail. And I wanted it to be too! But here’s why I don’t think it was the best fit for me:

    1. Thickest consistency

      The Birch Juice SPF is definitely a true cream. While the others were more like this “watery” / “gel” / “serum” vibe, the Round Lab one is a cream. And it is not a thick cream, but it is definitely thicker than the other two on this list. That’s not necessarily bad, especially in the winter. But when it is the summer and I want to wear less things on my face, having that little extra bit of bulk is definitely noticeable.

    2. A lot left over in the tube

      The tube for this is your conical looking tube, so very standard. However, I don’t think I normally get this much product left over in other tube products I’ve used. But when I cut this open because the tube stopped dispensing, I had a lot of product left. I would guesstimate that there was about 3-4 days of 2x a day application of this SPF! A win for my wallet, but a loss for my anxiety about having my product open to the air for a long time.

    3. Not much exciting in the “active” ingredient side of things

      Yeah, there’s hyaluronic acid (but there likely also is in the other skincare products you’re using in your routine). Yeah, there are your botanical extracts, but there aren’t as many as in the Skin1004 one. Yeah, there’s adenosine and ascorbic acid. And for those, I will say they are worthwhile call-out ingredients. But they’re also ingredients you can get in the other sunscreens and also in your other skincare. So there’s nothing crazy here (or honestly in any of the SPF products on this list, but that’s if we’re splitting hairs).

What’s the recommendation for sunscreen?

As the old adage goes, the best sunscreen is the one you’ll wear. So if that means the one that is more expensive, that’s great! If that means the one that is the cheapest, go for it!

If all else is equal (i.e. the promotions/price work out to be the same between products), I would recommend the Skin1004 Sun Serum the most highly over the other 2. It’s got a better finish, more ingredients to help your skin over time, and the lightest feel. I truly find it a pleasure to use.

But for all of them, unfortunately, you do have to do the dramatically long wait period through your traditional K-beauty retailers. It’s very annoying, but I much prefer these reputable retailers than taking a chance on Amazon and ending up with “SPF” that is not protecting you at all.

If you’d like to pick some up, here’s where to purchase them:







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