MACStack Mascara review: Does the "infinitely buildable" mascara live up to the hype?

Cast your mind back to last year and you may remember a certain “stackable” mascara bursting onto the scene and finding viral fame on social media. But if you never got around to picking it up yourself, our MACStack mascara review is here to take you through a deep dive into this relative newcomer to the beauty industry. 

In a world where the best mascara technology is already pretty advanced, you have to hand it to MAC for seemingly breaking the mold here. As well as its USP promising infinite buildability, the MACStack formula is available with two differently shaped brush heads to cater to different tastes. 

So how well does it fare? We've come to expect big things from one of the biggest makeup brands in the world, so our contributing beauty editor put both editions of the buildable formula through application and wear tests to report back on just how well it performs. Here's her in-depth analysis... 

Our beauty editor's MACStack mascara review

MACStack mascara packaging

MAC mascaras come in a variety of shapes and sizes, and MACStack’s design is no less unique – a fairly chunky black tube adorned with the brand’s iconic logo. The design is complete with a silver ball towards the top of the lid, which is a nice unique touch. If you can take or leave colorful packaging and love minimal designs, you’ll love it. 

The formula and ingredients

As mentioned, the key claim with the formula is that it is infinitely buildable or, to use the proper term from the brand, “stackable”. A little will give you a more natural look, and from there you can build it up as much as you like – 10, 20, 30 stacks, or more. Both iterations of the brush promise to feel weightless, not flake, and last for up to 24 hours, as well as separate and define lashes when used with the micro wand. 

Application and first impressions

I first tried MACStack when it initially launched in 2022, so revisited both wand sizes for this feature to ensure my feedback was based on more recent testing. As I don’t have thick or plentiful natural lashes I tend to favor the best lengthening mascaras over those that promise loads of volume, so it wasn’t a huge surprise that I got on better with the micro brush – and that’s exactly why MAC it out with two different brush sizes, after all!  

Although my go-to look isn’t building up lots and lots of volume (I like my lashes to look separated, long and defined), I found that with the micro wand I was able to achieve a nice defined look without lots of clumping – which is one of my pet hates – even after what felt like a lot of layers. The result with the smaller wand was nicely defined and lengthened lashes.

I found that the mega brush was able to collect a lot more product – so requires you to wipe off a bit more excess than micro – and although it was a bit large for my eye shape, build up a lot of volume. It was a bit too much for me but I’m confident that those who generally get on well with the best volumizing mascaras, or who love to build up product for a more dramatic finish or “night out” look, would really like it.  

How does it wear?

The good news is that MACStack ticks several very important boxes, I found that it didn’t smudge on me or flake under my eyes throughout the day. I also always curl my lashes before applying mascara and found that the MACStack formula held them in place well – they still had a lifted look several hours later, which was also a nice positive.

Just in case you're the kind of person who likes to push the boundaries of a mascara's capabilities, I would also note that this formula is not water resistant (though I wasn’t expecting it to be as it isn't billed as such). But thankfully, the bigwigs at MAC have solved that particular problem, as MACStack is now also available in one of the best waterproof mascaras for those who want buildable lashes that survive a dip in the pool. 

MACStack mascara review: The W&H verdict

First and foremost, I do think that MAC deserves some serious points for pairing this formula with different mascara brush types. Half of the mascara experience is down to the brush, and one that’s not quite right for me will put me off somewhat, so I really like the customized approach. The micro brush saved the day in that regard as I was able to enjoy the buildable fun on my sparser lashes, and I was impressed by its hold.

One of my core beauty beliefs is that mascara is the most subjective of all the makeup bag buys and so, because I prefer length over volume, this hasn’t quite knocked my go-to favorite off the top spot. But it did wear well, and I do think it’s a good one for those voluminous lash fans who like to be able to build and build their mascara. If that sounds like you, go ahead and try the mini edition (this means you can try without committing to the full spends, in case you’re not a fan), and give it a go!