All three are high-calorie gainers for people who struggle to eat enough, but they are built differently. CBUM Mass Gainer gives the most protein per calorie and costs the least per 100 calories at today's price. ON Serious Mass is the classic, simple weight gainer. Mass Tech Extreme 2000 is the most extreme, with about 2,150 calories in a full six-scoop serve. Most people do best taking a half or partial serve.
Side-by-side comparison
| Full label serve | CBUM Mass Gainer | ON Serious Mass | Mass Tech Extreme 2000 |
|---|---|---|---|
| Serve size | 275 g (4 scoops) | 336 g (2 scoops) | 564 g (6 scoops) |
| Calories | 1,070 | About 1,250 | About 2,150 (9,010 kJ, with water) |
| Protein | 53 g | 50 g | 62 g (with water) |
| Carbohydrate | 196 g | 252 to 254 g | 452 g |
| Creatine | 2.5 g | 3 g | 3 g |
| Full serves per 12 lb bag | 20 | About 16 | About 10 |
| Price | $139.95 | $169.95 | $159.95 |
| Cost per 100 Calories | $0.65 | $0.85 | $0.74 |
Cost per 100 Calories is worked out from the full serves per bag on each label, so treat it as a guide.
CBUM Mass Gainer: best overall
Each 4-scoop serve has 53 g of protein from whey concentrate, whey isolate and micellar casein, plus carbs from maltodextrin, pea starch, sweet potato, oat flour and quinoa, and 2.5 g each of creatine and glutamine. It has the best protein-to-calorie ratio of the three. Cookies & Cream is the best-stocked flavour.
ON Serious Mass: the classic
Serious Mass gives about 1,250 Calories and 50 g of protein per two heaping scoops, mostly from maltodextrin, with 3 g of creatine, 1 g of glutamine and added vitamins and minerals. It is simple and mixes easily. A smaller 6 lb bag is $98.95 if you want to try it first.
Mass Tech Extreme 2000: for hard gainers
A full serve is six scoops and about 2,150 Calories, which is more than many people's whole dinner. Most users take two or three scoops at a time. MuscleTech's label also gives 80 g of protein when mixed with 500 mL of skim milk.
How to use a mass gainer
- Start with a half serve to see how your stomach copes, and build up.
- Use it on top of meals, not instead of them.
- Aim for a steady gain: if your waist grows faster than your lifts, cut the serve size.
- Gainers are high in carbs, so people with diabetes or blood sugar issues should speak to their doctor first.
Our verdict
Best value and best protein ratio: CBUM Mass Gainer. Simplest classic: ON Serious Mass. Most calories: Mass Tech Extreme 2000. Want fewer sugars and fillers? Read our R1 Clean Gainer review or the best mass gainer guide.
Shop the products in this guide
CBUM Mass Gainer 12 lb$139.95
ON Serious Mass 12 lb$169.95
Mass Tech Extreme 2000$159.95
ON Serious Mass 6 lb$98.95
Browse all mass gainers or the weight gaining stacks.
FAQs
Which mass gainer has the most calories?
MuscleTech Mass Tech Extreme 2000 has the most, at about 2,150 Calories per full six-scoop serve mixed with water. ON Serious Mass has about 1,250 Calories per serve and CBUM Mass Gainer has 1,070.
Is CBUM Mass Gainer better than Serious Mass?
CBUM gives more protein per calorie (53 g per 1,070 Calories versus 50 g per 1,250) and uses a wider mix of carbohydrate sources. At today's price it is also cheaper per 100 Calories. Serious Mass is simpler and suits people who want the most calories per scoop.
Do I have to take a full serve of mass gainer?
No. Full serves are very large. Many people take a half serve once or twice a day, on top of meals, and adjust based on how their weight changes.
How fast should I gain weight?
Gaining too fast mostly adds fat. Aim for a slow, steady increase while your strength goes up, and reduce your serve size if your weight climbs much faster than your lifts.
Sources: ISSN protein position stand (2017); product labels and brand nutrition panels, checked October 2026.
Order online with Australia-wide delivery, free on orders of $99.99 or more, or visit a Supps247 store in Melbourne, regional Victoria or Brisbane to compare products in person. Members can use our member price match on full-priced items.
Prices and stock were checked on 22 October 2026 and can change at any time. Always read the label and follow the directions for use. If you have a medical condition, are pregnant or take regular medication, check with your doctor first.
