Ultimate Nutrition Iso Mass Xtreme Gainer Review

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Andy Williams
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Ultimate Nutrition Iso Mass Xtreme Gainer is designed for bodybuilders who are seeking a mass gainer with a high-quality formula that will get them results.

Ultimate Nutrition has been around for a long time, so I was expecting their mass gainer to be really good. And while it was hard to get hold of in the UK, I decided to order a tub (or should I call it a barrel?) so that I could do a detailed Ultimate Nutrition Iso Mass Xtreme Gainer review to see if it’s the best mass gainer for skinny guys to pack on muscle.

ideal for bulking
Ultimate Nutrition Iso Mass Xtreme Gainer
A front view of Ultimate Nutrition Isomass Xtreme Gainer
Taste: 9/10
Mixability: 8/10
Ingredient Quality: 9/10
Mass-Building Potential: 9.5/10
Overall Rating: 8.9/10
  • Contains 570 calories per serving to promote weight gain
  • Has an excellent carbs-to-protein ratio for building muscle
  • Formulated with 7.5g of creatine
  • Includes added BCAAs, glutamine, vitamins, and minerals
  • Uses healthy fats for extra calories
  • Mixes really well
  • It’s expensive
  • Uses artificial (as well as natural) flavours

Ultimate Nutrition Iso Mass Xtreme Gainer Ingredients

Each Ultimate Nutrition Iso Mass Xtreme Gainer serving contains 570 calories (820 with milk), 60g of carbs, 60g of protein, and 10g of fat. 

Based on the product description, it appears there could be another formula as well that has 80g of carbs and 65g of protein. Either way, this gainer has great macros for gaining muscle. I really like how the carbs-to-protein ratio isn’t ridiculously high, as with so many other gainers.

Ultimate Nutrition Iso Mass weight gainer is split into different mass-building ingredient blends, each of which serves a different purpose.

Iso Mass

Iso Mass is the protein blend that lies at the heart of Iso Mass Xtreme Gainer. Each 157g serving contains 60g of high-quality protein from a diverse range of sources, namely whey isolate, whey hydrolysate, egg protein isolate, casein, and lactoferrin.

Whereas many mass gainers rely on just whey—or even worse, soy—this Ultimate Nutrition mass gainer uses a blend of quick-release and slow-digesting proteins so that your muscles can benefit from a consistent supply of amino acids.

Carbo Mass

The supplement facts for Ultimate Nutrition Isomass Xtreme Gainer

Carbo Mass is a powerful carbohydrate blend that energizes your body and gives you those extra calories you need to gain weight and muscle mass.

As with the protein blend, the carb blend is also diverse, providing carbohydrates with differing absorption speeds so that you get a steady supply of energy without the sugar crash.

Specifically, you get waxy maize, whole oat flour, dextrose, oat fibre, and rice maltodextrin.

As you probably know, the majority of weight gainers just use maltodextrin. And while effective in reasonable doses, maltodextrin is best used in conjunction with other carbs so that you can get more consistent energy.

If you’re looking for a higher carb gainer, then Ultimate Nutrition Muscle Juice Revolution 2600 is a solid option, as is Ultimate Nutrition Muscle Juice 2544, which has over 1,000 calories per serving.

Crea Mass

Crea Mass is a 7.5g creatine blend that aims to increase your strength and muscle power. As well as classic creatine sources like creatine monohydrate, this blend contains creatine magnesium chelate, creatine phosphate, di-creatine orotate, creatine alpha ketoglutarate, and di-creatine malate.

Creatine alpha ketoglutarate is an especially exciting inclusion because this form is creatine is believed to be absorbed into the muscles faster than regular monohydrate.

Clearly, Ultimate Nutrition has thought out every detail of Iso Mass Xtreme Gainer so that it contains only the most effective ingredients.

Omega Mass

The macros for Ultimate Nutrition Isomass Xtreme Gainer

While many people still believe that fats are the enemy, healthy fats are extremely important for overall bodily functioning. If your body is healthy, then it’s naturally going to have a better foundation from which to build muscle.

Also, at 9 calories per gram, fats are the most energy-dense macronutrient, making them an integral part of any bulking regime.

This 6.5g omega mass blend consists of canola oil, sunflower oil, MCTs, borage seed oil, flaxseed oil, and omega 3 fish oil.

I like that Ultimate Nutrition Iso Mass Xtreme Gainer includes enough fat to support health and weight gain without going overboard. This way, the fat won’t slow down protein absorption.

Vita Mass

Although some bodybuilders might roll their eyes at the inclusion of vitamins and minerals in a hardcore mass gainer, vitamins and minerals are great to have when you’re drinking liquid calories.

As I mentioned earlier in my Iso Mass Gainer review, when the body is healthy, it’s better able to build muscle mass.

So although vitamins and minerals alone probably won’t persuade anyone to get this Ultimate Nutrition weight gainer, they’re still an integral patriot of this high-calorie formula.

Gluta Mass

This 2.5g glutamine blend consists of various forms of glutamine so that your muscles can recover quicker and get rid of some soreness.

As we’re beginning to see, Iso Mass Xtreme Gainer isn’t your typical protein-and-carbs mass gainer; like Protein Dynamix Mass Gainer, it’s an all-in-one supplement for gaining muscle mass.

N.O. Mass

Who doesn’t love a good gym pump? This 600 mg N.O. blend might not replace your pre-workout anytime soon (I mean, it’s not even 1g), but it does contain citruline malate and l-aspartic acid in addition to 3 forms of arginine.

Obviously, this Ultimate Nutrition mass gainer is for repairing and building muscle—not getting a pump. Still, it doesn’t hurt to top up your supplies of proven nutrients like arginine and citrulline malate.


In addition to the 60g of protein—which naturally contains plenty of BCAAs of its own—Ultimate Nutrition has formulated Iso Mass Xtreme Gainer with an additional 3g of BCAAs.

These branched-chain amino acids will help your muscles to recover quicker from your workouts so that you can start making gains sooner.

Performance Mass

Beta alanine, l-glycine, and l-methionine are the trio of amino acids that make up this performance mass blend.

While glycine and methionine do more for health than muscle mass, beta alanine can boost your gym performance by enhancing your muscular endurance, enabling you to do more reps and sets.

Enzyme Mass

To finish things off, Ultimate Nutrition Iso Mass Gainer contains a 250mg bend of digestive enzymes so that you can make the best use of all these nutrients that you’re taking in.

The inclusion of digestive enzymes also helps you to digest the calories so that the gainer doesn’t sit too heavy on your stomach.

Ultimate Nutrition Iso Mass Xtreme Gainer Mixing and Taste

Ultimate Nutrition Iso Mass Weight Gainer is available in around 7 different flavours—Banana, Chocolate Milk, Chocolate Peanut Butter, Cookies N Cream, Iced Coffee, Soft Vanilla Ice Cream, and Strawberry Milkshake.

Mass gainers aren’t exactly known for their great taste, and Iso Mass Xtreme Gainer does have mixed taste reviews. However, I personally enjoyed the Chocolate Milk flavour and would happily drink it again.

Also, the mixability is excellent. Just use about 450 ml of water or milk and give it a good shake. You won’t get any clumps or unmixed powder, and the consistency is really smooth.

I’d love to be able to give my opinion on every flavour, but I’ve only tried chocolate!

On the whole, though, I think that most Ultimate Nutrition Iso Mass Xtreme Gainer reviews were very complimentary towards the taste, so just go with whichever flavour takes your fancy.

Who Should Use Ultimate Nutrition Iso Mass Xtreme Gainer?

If you want to gain muscle mass and don’t need a gainer with an extremely high amount of calories like MuscleTech Mass Tech Extreme 2000, then Iso Mass Xtreme Gainer is a good option.

If you take the recommended two daily servings, then you’re getting well over 1,000 calories with water and over 1,600 calories with milk.

I especially like that Ultimate Nutrition Iso Mass Gainer doesn’t contain loads of junk carbs. Instead, the protein and carbohydrate dosages are very similar, enabling your body to benefit from balanced nutrition.

Also, if you like the idea of having an all-in-one gainer (i.e. not having to take your creatine separately), then Iso Mass Xtreme Gainer definitely has that convenience factor going for it.

Who Should Avoid Ultimate Nutrition Iso Mass Xtreme Gainer?

If you just want to maintain your current weight, then Ultimate Nutrition Iso Mass Xtreme Gainer is likely not the best choice for you because of its calorie-dense formula.

Also, since this Ultimate Nutrition mass gainer is on the expensive side, you might want to look for cheaper alternatives if you’re bulking on a budget.

If you have two servings each day, then one tub, which costs over $100, will last you roughly two weeks. Some people might be able to justify the expense if they’re getting great gains, but others might be able to get comparable results from significantly cheaper supplements.

The Verdict On Ultimate Nutrition Xtreme Iso Mass Gainer

Overall, Ultimate Nutrition Xtreme Iso Mass Gainer is an excellent, albeit expensive, supplement for putting on quality muscle.

The attention to detail that Ultimate Nutrition has put into this weight-gain formula is truly impressive. And while I still think there are better options—especially for the price—you’ll definitely make some great gains while taking Iso Mass Xtreme Gainer.

With that said, I hope that my Ultimate Nutrition Xtreme Iso Mass Gainer review gave you a good insight into this supplement. Hopefully, you can decide if it’s right for you and your fitness goals!

The #1 UK Mass Gainer
Crazy Nutrition Mass Gainer
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  • Contains 488 bulking calories from 100% clean sources
  • Packed with a proven 40g protein blend for quick muscle repair and growth
  • Provokes noticable weight gain with 55g of complex carbs from oats
  • Tastes amazing (to my surprise!) and mixes easily
  • Offered at the absolute lowest UK price during July
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Andy Williams
Andy Williams is a UK-based personal trainer and bodybuilder who coaches gym-goers of all levels using proven evidence-based techniques in strength training, nutrition, and supplementation. He’s tested over 70 different mass gainers for their ingredient quality and muscle-building effectiveness and regularly shares his findings in his mass gainer reviews.
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