One/Size

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B12 Base Thinner Vitamin Pearl Serum"The one size base thinner is a really amazing product if you don't really care to buy more complexion products."$36

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B12 Base Thinner Vitamin Pearl Serum

4.9Variant: Pink Version

“The one size base thinner is a really amazing product if you don't really care to buy more complexion products”15:41–15:47
“I cannot tell you how much I've been using this. I use this almost every single day”16:00–16:06
“You can take like your most full coverage foundation. And depending on the ratio of the base thinner that you've used, you can turn it anywhere from a light coverage foundation to a barely their skin tint”16:04–16:09
“This is incredible”
“I even really like it with concealers”16:29–16:33
“Couple drops of this mixed with that cream concealer, I really do get my ideal coverage point”
“I can take any of my favorite foundations and magically turn them into a skin tint”
“This is a really nice functional product”
Source: Sephora 2026 Sale Top Recommendations - Apr 5, 2026

Dacey Cash517K subscribers

4.9Variant: Bronze

“I'm a huge fan of this. This is my original like the pink one. I love this stuff”1:22–1:27
“You can use it to prime or to cut down coverage of concealer, foundation. You can mix it in with liquid blushes. It's just a really nice product that doesn't pill”1:40–1:46
“I actually think the bronze one is really nice for summer cuz it's just going to give you a little bit of that sun-kissed glow”2:03–2:08
“My skin literally looks like glass. I'm like obsessed with how glowy it makes my skin”2:57–3:04
“It's really nice to play around with, and you get so much more like versatility out of the makeup that you already own, and you don't have to worry about it peeling”3:20–3:23
“I also feel like it doesn't conflict with the finish of the makeup too much”3:27–3:32
Source: Full Aussie Girl Glam Look & Sephora Sale Haul - May 3, 2026

Dacey Cash517K subscribers

4.8

“It leaves the prettiest golden pearl glow”1:35–1:40
“As somebody who has dry skin, this is very hydrating”1:37–1:42
“It doesn't feel too heavy on the skin and it's actually impactful”1:40–1:46
“When you mix it into foundation, it actually has that glowy hydrating impact on the foundation as well”1:49–1:58
“It doesn't get lost in the foundation like a lot of other products that have similar claims”1:58–2:04
“It's just a really high quality product that does exactly what it says”2:04–2:08
“It adds so much rejuvenation to my skin and the glow is gorgeous”2:10–2:17
“Stunning, impeccable, pearly, golden”2:15–2:19
Source: Best makeup of 2025 (tried 400 products) - Dec 19, 2025

Morgan Turner370K subscribers

4.5

“This is a vitamin pearl serum foundation fortifier and mixing medium that lets you customize the finish of your foundation while getting skin care benefits in the process”11:09–11:14
“It gives you this really natural looking luminosity with these pink and gold pearl pigments. There's nothing shimmery or glittery about this at all”11:18–11:24
“I can take matte foundations and turn them into luminous matte foundations that don't look overly glowy or oily and it doesn't change the texture or the coverage of the foundation”11:27–11:32
“I think this was such a great kind of innovative launch in 2025. We didn't see anything else like this”11:53–11:59
Source: Best makeup of 2025: my standout favorites - Dec 18, 2025

Stephanie Marie279K subscribers

4.2

“This is incredibly versatile. You could use this as a luminizer. It's going to give you that nice glow on the skin without the grease”4:22–4:28
“If you have a foundation that you love, but it has too much coverage... you are going to thin it out and give it more glow without changing the formula with a B12 base thinner”4:38–4:47
“It has a lot of great ingredients for your skin. So, it's not just a makeup product. This is helping your skin as you use it as it has a lot of B12, C vitamin and E vitamin”5:04–5:10
Source: Best makeup in 2025 - Jan 11, 2026

Ali Andreea1.4M subscribers

4.2Variant: Pink Pearl

“This is something that you could use on its own. As you can see, it gives you a very natural glow, but like the most natural glow”7:27–7:33
“Or you can use it to mix this product with your foundation to make it even thinner”7:33–7:37
Source: Nina Park inspired makeup look - Feb 22, 2026

Ali Andreea1.4M subscribers

MENTIONSVariant: Bronze

“One size came out with a new bronzing version of their b12 base thinner”0:32–0:35
“You can use it as a primer as a serum or you can mix it with your foundation to thin out your foundation”0:36–0:40
“You can mix this with your foundation, it kind of makes it more of like a skin tint”0:43–0:45
“It gives it a really beautiful glow and it's also shearing out the coverage to make it more like a skin tint”0:44–0:47
Source: Full Face of New Makeup Launches - Mar 12, 2026

Skyler Renee78K subscribers

Brand note

One/Size is a brand that's carved out a clear lane in setting sprays, specifically with formulas that address the tension between wanting makeup to last and not wanting it to look powdery or flat. The Powder Melt Glass Setting Spray is the standout here — it creates a film over the complexion that extends wear time while melting powders into the skin for a dewy-but-not-sticky finish. Creators consistently note it's best for those who dislike the look of powder or want a glassy sheen without feeling tacky. The trade-off?

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