International Protein Extreme Mass Gainer

International Protein Extreme Mass is a high-calorie mass gainer with a 50:50 protein to carb ratio. One serve (3 scoops, 100 g) gives you 429 calories, 42.5 g of protein and 42.5 g of carbs from five protein sources, rice starch and glucose polymers, plus healthy fats including MCTs. Mixed with 500 ml of low-fat milk, one shake gives you about 674 calories and 62.5 g of protein. Choose a 1.5 kg pack (15 serves) or a 4 kg pack (40 serves), in 5 flavours plus a multi flavour pack. International Protein is an Australian-owned brand.

Why choose Extreme Mass gainer

Extreme Mass by International Protein is a high-calorie, nutrient-rich formula built to support serious lean mass and size gains. Extreme Mass is perfect for hard gainers and active people. The formula combines five premium protein sources with complex carbs and a blend of healthy fats, including MCTs, canola and sunflower oils. Together they give your body a steady supply of energy and nutrients to fuel training, support recovery and keep you in an anabolic state for muscle growth.

Unlike typical carb-heavy gainers, Extreme Mass gives you a balanced macro profile, with concentrated calories and no excessive sugars. The five-stage protein blend of hydrolysed whey, whey protein isolate (WPI), whey protein concentrate (WPC), micellar casein and egg albumen digests at different speeds, for sustained amino acid release. The carbs come from rice starch and glucose polymers, which give both quick and long-lasting energy to support intense workouts and fast metabolisms.

Extreme Mass is ideal for athletes, bodybuilders, tradies and anyone with high energy needs. Extreme Mass also suits people recovering from illness or anyone who needs extra calories. Extreme Mass is a convenient, delicious way to build lean mass and achieve serious growth.

What Extreme Mass helps with

• Gaining weight: 429 calories per serve with water, or about 674 with 500 ml of low-fat milk.
• Lean muscle: 42.5 g of protein and 4,490 mg of leucine per serve, with a 50:50 protein to carb ratio.
• Steady fuel: rice starch, glucose polymers and healthy fats for quick and lasting energy.
• Fewer sugars: 9 g of sugars per serve, for a gainer without excessive sugar.

Nutrition per serve

With 500 ml of low-fat milk, one serve gives about 674 calories, 62.5 g of protein, 71.5 g of carbs and 38 g of sugars. Figures are from the Extreme Mass label shown on this page. Check the label on your pack.

What is in the protein blend?

Extreme Mass uses five protein sources. Hydrolysed whey and WPI digest fast, WPC digests at a medium speed, and micellar casein and egg albumen digest slowly. Mixing fast and slow proteins gives you sustained amino acid release.

How many calories do you need to gain weight?

To gain weight, you need to eat more calories than you burn each day. Most people aim for about 300 to 500 calories above their usual intake for slow, lean gains. One serve of Extreme Mass with milk covers about 674 calories, so one or two shakes a day on top of your meals can make the surplus much easier to hit.

How to take Extreme Mass

Add 100 g (3 scoops) to 500 ml of low-fat milk or soy milk in a shaker or blender. Blend in a banana or berries for an extra energy boost. Have 1 serve 2 to 3 times a day on top of your normal meals to cover your nutrition needs when you want to gain weight. The best times are mid-morning, mid-afternoon and before bed, or whenever you need extra calories. Mixing with water gives you fewer calories if you want a lighter shake.

Sizes and price per serve

• 1.5 kg (15 serves): $119.95, about $8.00 a serve.
• 4 kg (40 serves): $239.95, about $6.00 a serve.

The 4 kg pack is the better value if you take Extreme Mass every day.

Flavours

Caramel Popcorn, Choc Banana, Chocolate Truffle, Strawberry and Vanilla Ice Cream. The 4 kg size also comes as a Multi Flavour Pack. Not sure which to choose? Extreme Mass is covered by our Love the Taste Guarantee. Try up to 5 serves within 30 days. If you don't love the flavour, swap for another or take store credit.

Who should take Extreme Mass?

Extreme Mass is a good fit for hard gainers who struggle to eat enough, athletes and bodybuilders in a building phase, tradies and other people with physical jobs, and anyone who needs extra calories, including people recovering from illness under medical or dietary advice. Extreme Mass is not suitable for children under 15 or pregnant women.

Side effects

Big shakes can cause bloating or a heavy feeling if you are not used to them. Start with one serve a day and build up. Extreme Mass is made with milk and egg proteins, and may contain traces of soy, gluten, tree nuts and sesame, so skip Extreme Mass if you have an allergy to any of these. Extreme Mass is not a sole source of nutrition, so use Extreme Mass with a sensible diet and exercise program.

What to take with Extreme Mass

• Creatine: 3 to 5 g a day of Booty N Buff Essential Creatine pairs well with a building phase.
• Protein between shakes: Dymatize ISO100 or Rule 1 R1 Whey Blend if you want extra protein without the extra calories.
• Pre-workout: Nexus PER4M 2.0 or Faction Labs Disorder to fuel heavy sessions.

Extreme Mass vs other mass gainers

• International Protein Extreme Mass: 429 calories and 42.5 g of protein per 100 g serve, 50:50 protein to carbs, five protein sources.
• Emrald Labs Post Mass: 634 calories, 27.9 g of protein and 119 g of carbs per 160 g serve, with creatine and digestive enzymes. A higher-carb choice.
• Optimum Nutrition Serious Mass: a well-known high-calorie gainer for the biggest calorie needs.
• Rule 1 R1 Mass Gainer, BSN True Mass 1200, Dymatize Super Mass Gainer, Optimum Nutrition Gold Standard Pro Gainer and RAW CBUM Mass Gainer: more gainers to compare.

Looking for something else? Browse all weight gain products or the full International Protein range.

Where to buy Extreme Mass in Australia

Booty N Buff stocks International Protein Extreme Mass and ships Australia-wide from our store in Caringbah, NSW. Order by 2pm on a weekday for same-day dispatch.