Last Updated: Monday 26th October 2026

What Is a Mass Gainer?

A mass gainer, also called a weight gainer, is a high-calorie protein powder that combines protein with carbohydrates and, in some formulas, fats. It's designed to help you add extra calories and protein to your day when it's hard to eat enough through food alone. Most mass gainers are mixed with water or milk and can provide from around 230 to over 2,000 calories per serve, depending on the product and serve size.

At Nutrition Warehouse, we stock mass gainers and weight gainer protein powders from Optimum Nutrition, Anabolix Nutrition, Genetix Nutrition, Max's Supplements, MuscleTech and more. They're part of our full protein powder range. Want to see which protein powders customers rate highest? Check out our Top 10 Protein Powders.

Mass Gainer vs Weight Gainer vs Protein Powder

"Mass gainer" and "weight gainer" are two names for the same type of product. The main difference is between gainers and standard protein powder:

If you only want extra protein without the added calories, browse our whey protein range instead.

Types of Mass Gainers

Mass gainers vary mainly in how many calories they provide and the ratio of carbohydrates to protein. Here's how they compare:

Calories also depend on whether you mix with water or milk, so always check the nutrition panel for the serve you'll use.

Who Are Mass Gainers For?

• People who struggle to eat enough: a convenient way to add calories between meals.
• High training loads: athletes and active people with high daily energy needs.
• Busy schedules: a quick shake when there isn't time for an extra meal.
• Physical jobs: people whose work burns a lot of energy through the day.

Mass gainers add calories, so they're best used as part of a diet and training plan suited to your goals.

How to Choose the Right Mass Gainer

1. Calories per serve: work out how many extra calories you want each day. A lean gainer suits a small increase, while a high-calorie gainer suits a large one.
2. Protein to carb ratio: some gainers have several times more carbs than protein, while others are closer to 1:1 or 2:1.
3. Serve size: some full serves are 3 to 6 scoops, so check how many scoops make one serve.
4. Added ingredients: many gainers add creatine, glutamine or vitamins and minerals. Check the label if you already take creatine.
5. Dietary needs: most gainers contain dairy. Choose a plant-based gainer if you need a dairy-free option.
6. Testing: if you compete in tested sport, look for a product that's batch tested for banned substances.
7. Cost per serve: compare the number of serves per bag, as large serves mean fewer serves per bag.

How to Take a Mass Gainer

Always follow the serving size and directions on your product label. Most mass gainers are mixed with water or milk in a shaker or blender, and can be taken between meals or after training. If a full serve is too much, many labels suggest splitting it across the day. Mass gainers are a supplement to your diet, not a replacement for meals. If you have a medical condition or take medication, speak to your healthcare professional before use.

Shop Popular Mass Gainers

• Mammoth Pro Gainer by Anabolix Nutrition: a 50:50 protein to carb gainer with 3g creatine per serve, 25 or 66 serves
• Gold Standard Pro Gainer by Optimum Nutrition: 650 calories and 60g protein per serve
• Clean Mass by Max's Supplements: 460 calories and 36.2g protein per serve
• Absolute Mass by Max's Supplements: around 1,180 calories and 60.8g protein per serve with whole milk
• Mass Tech Extreme 2000 by MuscleTech: over 2,000 calories and 60g protein per full serve
• Clean Gainer by Rival Us: 560 calories and 30g protein per serve, with carbs from quinoa, oat fibre and brown rice
• Extreme Mass by International Protein: a high-calorie gainer with five protein sources and MCT oil

Browse the full range above to compare every flavour and bag size.

Looking for a Tested Mass Gainer?

If you compete in drug-tested sport, choose a product that's been batch tested for banned substances, such as Natural Mass by Prana ON (HASTA certified). You can also browse all HASTA certified supplements.

Other Types of Protein

• Meal replacement shakes: balanced shakes designed to replace a meal
• Plant-based protein: dairy-free protein powders
• Carbohydrate supplements: carbs on their own to add to your protein shake

What to Pair with a Mass Gainer

• Creatine: check your gainer label first, as many already contain creatine
• Pre-workout: for training days

Why Buy Mass Gainers from Nutrition Warehouse?

• Mass gainers and weight gainers from trusted brands, all in one place
• Expert advice in-store and online across 120+ locations
• Click & Collect available same day
• SameDaySupps delivery in select metro areas
• Free shipping over $150
• Best Price Guarantee: we'll beat any competitor by $1 and throw in a free shaker
• 5 Scoop Guarantee: try up to five scoops and return it if you're not satisfied