This Serum Helped Minimize Stubborn Dark Spots I've Had for Years

Elle

20-05-2025

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Due to the nature of my job, I'm constantly in a hamster wheel of trialing beauty formula after formula, and after a while they tend to blur together. It's honestly pretty rare that a skin-care product impresses me enough to land a permanent place in my routine. Eucerin Radiant Tone Dual Serum, which helped visibly reduce the appearance of my dark spots over a span of 12 weeks, is the latest to earn entry into that inner circle.
Eucerin spent 10 years on research and development to finalize the products in the new Radiant Tone collection. The line's star ingredient is Thiamidol, a patented compound that helps treat and prevent the appearance of dark spots with continued use. The Radiant Tone Dual Serum also contains hyaluronic acid to hydrate.
When I first started using the serum, I was hoping it would sufficiently moisturize my skin (so I wouldn't have to layer another serum on top) and fade the dark spots that have populated my cheeks and temples for years. Keep reading to find out what actually happened during and after I incorporated Eucerin Radiant Tone Dual Serum into my routine for a full 12 weeks.
Week 1
The serum feels pleasant on the skin and hydrates without feeling sticky. It's only been a week, so there aren't any big changes to note here.
Week 2
It's freezing outside, but my skin doesn't feel dry thanks to this serum. I looked in the mirror today and was shocked at how much brighter my skin looked than last week. Could it already be working?
Week 3
I don't see much of a difference this week compared to the last; however, I know I need to give the serum a few more weeks to work its magic. Patience is key here, folks!
Week 4
Still, nothing has visibly changed since week two, but I'm not worried. The serum hasn't caused any inflammation or breakouts—which has been known to happen when I'm trying a new product—so that's a plus.
Week 5
I got some microneedling done all over my face and neck last week, so I had to keep my routine super-simple and wasn't able to use the serum for a few days. I'm glad to be back using it, though—I missed the moisture.
Week 6
I can see that the darkest cluster of dark spots on my left cheek has faded significantly, and I don't have to use as much concealer on it.
Week 7
My skin is still loving the formula; if I forget to apply it, I definitely notice a difference in both hydration and brightness.
Week 8
My dark spots are continuing to lighten up. I feel like I'm using less and less concealer and foundation to even out my complexion.
Week 9
The weather here in New York City is warming up, and my skin doesn't need quite as much extra moisture as it did before. However, I'm still appreciating the hydration boost in my nighttime routine and when I wake up, my skin looks smooth and radiant.
Week 10
Looking at photos, I'm shocked by the difference I see; my complexion looks clearer and brighter. This is a testament to how consistency with the right skin-care product can yield real results.
Week 11
I've been in Miami this week, and I've been getting compliments on my skin left and right. My friend's mom, who owns a company that sells professional aesthetic equipment, told me that it looked perfect and that she couldn't think of a single aesthetic treatment I should try—that was super meaningful to me, considering that I was on a potent medication a few years ago to treat my cystic acne. And my dark spots have lightened so much in the past 11 weeks that I feel confident being out and about without makeup.
Week 12
Just under the wire, my bottle completely ran out this week. I could tell how much I actually loved the serum from the pang of sadness, and even slight panic, I felt when I realized I was down to the last drop. And even after baking in the subtropical sun of South Florida last week, my remaining dark spots didn't get any darker. Pretty impressive.
Although my original spots weren't very dark, there were so many of them that my eyes always immediately gravitated toward them in the mirror. Now all I see is luminous, clear, healthy-looking skin. Some of the dark spots are gone entirely, and the remaining ones appear significantly lighter.
I keep flipping back and forth between my before and after photos, and even though I lived it, I can't believe the results. I definitely recommend Eucerin Radiant Tone Dual Serum to anyone looking to combat dark spots—and I can't wait to break open another bottle.