SISU NextGen 2.4mm Max Guard review

SISU NextGen 2.4mm Max Guard review


SISU is a brand who have built a brilliant business around one simple guarantee: More protection, less mouthguard. The company was started in the USA, based in Saline, MI, with the founders originating in Sweden. The company were named one of the fastest growing companies in the United States by Inc. Magazine in 2016, which isn’t surprising considering the sheer amount of research and originality in their mouth guards, as these are vastly different from anything else on the market. SISU sent us one of their NextGen Max Guards to review.

About the Mouth Guard

Many people have heard of SISU thanks to their unique approach to mouthguards, with their original guards, but they have since come back with a new and improved design, the SISU NextGen. After our review of the original SISU Max, we were keen to get our hands on the new model to see how things have changed.

For those who don’t know already, the SISU comes as a flat arc, which when moulded fits to closely to the teeth protecting the tiny crevices which your typical boil and bite mouthguard can’t get to. The thicknesses of the two NextGen guards are the same as the originals, with the Aero Guard measuring in at an absolutely tiny 1.6mm thick, and the Max Guard measuring at only 2.4mm.

If you thought 2.4mm sounded pretty thin, that’s because it is. According to SISU, it’s 30% thinner than conventional mouth guards, but uses unique medical grade thermo-polymer materials which give it 142% better impact energy absorbtion than a conventional mouthguard, which is really impressive. If you want to find out more, check out The Science of SISU, a whole page dedicated to the statistics of the SISU’s performance.

The first thing you’ll spot when you compare the NextGen to the original is that the holes in the guard are distributed differently, with the perforations now spread out slightly more and positioned in a triangle at the front of the teeth to help direct the shock and help absorb strikes.

SISU NextGen 2.4mm Max Guard review


As mentioned in our previous review, the SISU is a little bit different to fit than a regular mouth guard. When you first get the guard, it’s a flat, boomerang shaped piece. You then need to follow the instructions included to heat it up and mould it. Unlike a boil and bite mouthguard, you don’t quite want to bite down hard and suck. Instead, it’s a slightly more delicate, lining up your teeth to the bite pad and shaping the guard mostly with your fingers and a little bit of suction.

If you’re looking to mould the mouth guard for the first time, the video below will give you a much better guide on how to do it.

When moulding my NextGen Max Guard, I must admit I messed it up a bit first time, and managed to get an awkward point sticking out at the front. Thankfully the SISU is re-mouldable, so popping it back into the hot water and a second attempt helped me sort it out and I ended up getting a much better fit by the end of the moulding process.

While I didn’t get it perfect first time, I did notice that they’ve increased the size of the bite pad, which makes it much easier to get the positioning right. It’s also now possible to tell which side is the bottom and the top, which simply wasn’t possible with the last version.


The SISU NextGen is available in the same 6 colours as the original – blue, red, black, white, pink and purple. There aren’t any fancy designs or visuals available, however they aren’t designed for that. The solid colours are nice and bold though, so they stand out well and still look great. We were sent a black guard, which as it happens looks just the same as any other mouthguard from a distance.

SISU NextGen 2.4mm Max Guard review


Having used the original SISU Max, I’m used to the thickness of the guard already, however I know a lot of people find it a bit weird to start off with. Once you get used to it though, I find it’s a much more pleasant experience than with other mouthguards, and as I pointed out in our review of the original, it’s pretty easy forget that it’s there completely. While testing out the NextGen I actually almost left it in after a sparring session, and was about to start doing the end-of-class exercises with it still in, only realising when I spoke to a training partner.

The fact that it’s so unobtrusive is one of the main selling points of the SISU. It stays in place so you don’t have to bite down to hold it in, which means you have much more freedom when it comes to communicating with sparring partners, grabbing a drink between rounds or even just breathing. The fact it stays in place is good for other reasons too. You might have seen one of the many videos where a fighter is hit so hard he spits his mouthguard out, or loses it in between rounds. UFC Fighter Michael Bisping very nearly got knocked out by Anderson Silva because he was distracted by his mouthguard coming out mid-fight. With the SISU, its slimmer nature and custom fit hold it in place well enough that it shouldn’t need to come out at all. Someone tell Bisping…

SISU NextGen 2.4mm Max Guard review

One downside to the SISU is that it’s not the most comfortable thing to bite down on, although I feel like this is slightly unavoidable. It’s a solid material, and much sturdier than other mouthguards, so biting hard isn’t quite as pleasant as biting into a gel-lined mouthguard for example. That said, it is probably going to keep its fit for longer and it can’t be chewed on as easily either, so I feel like it’s a necessary sacrifice.

My major complaint when testing the original Max Guard was that the edges were sharp, however the NexGen Guards now use rounded edges instead (We’re going to go ahead and assume that we single-handedly influenced this change. You can thank us later). Okay, so it doesn’t sound like a huge difference, but it actually affects a lot. Putting the guard in feels easier, it also won’t scrape on your gums when putting it in, it gives you something better to hook onto when taking it out, there are no sharp edges to press against your lips when taking a punch to the mouth, and it even gives the tongue a smoother surface to sit against. These small improvements may not seem like much individually, but all add up to a much more refined feeling product.


The SISU NextGen 2.4mm Max Guard comes in at $34.99, the same price as the original Max Guard, so there’s no reason not to get this improved model. Each guard also comes with a $35,000 one year warranty, which is higher than the average warranties that we’ve seen, and even slightly higher than other reputable brands such as Shock Doctor and Under Armour.

This definitely isn’t a cheap mouthguard, but it’s also far from the most expensive – some major brands offer models in excess of $50 for example, and professional custom made mouthguards will set you back even more than that.

At the end of the day though, it’s about finding the best protection you can – you need to be confident that when you get punched, kicked, elbowed or even kneed in the face that your teeth are going to be as protected as can be.

Looking to buy this?

SISU NextGen Max Guard














We like

  • Tight fit allows easier drinking, talking and breathing
  • Can drink, breathe and talk with ease
  • Re-mouldable if you get the fit wrong

We don’t like

  • Takes a bit of getting used to
  • Limited single colour options

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