Optimum Nutrition Pro Gainer – Premium Mass Gainer

Optimum Nutrition Pro Gainer 10lb — 60g Protein, Controlled Carbohydrate

Pro Gainer is the leaner half of Optimum Nutrition's mass-gaining range. Where Serious Mass maximises calories, Pro Gainer maximises protein — 60g per serve with a controlled carbohydrate load and over 20 vitamins and minerals, built for people who want to add size without the fat that comes with an aggressive surplus. 10lb tub. In stock at TopDog Nutrition.

Pro Gainer vs Serious Mass — The Real Difference

These aren't two sizes of the same idea. They solve different problems.

Serious Mass is a calorie tool: 1,250+ calories and 250g+ of carbohydrate per serve, with 50g of protein. It exists for people who genuinely cannot eat enough — fast metabolisms, poor appetites, very high activity levels. It's carbohydrate-dominant by design.

Pro Gainer flips the ratio: 60g of protein per serve at a considerably lower total calorie count, with the carbohydrate dialled back. It's a protein-forward gainer, which means a more moderate surplus and less of it stored as fat.

The practical rule: if you're eating well and still not gaining, Pro Gainer. If you're barely eating and desperate for calories, Serious Mass.

60g Protein — Why That Number Matters in a Gainer

Most gainers are carbohydrate with protein attached, because carbohydrate is cheap and calories are the selling point. 60g per serve puts Pro Gainer well ahead of that pattern.

It matters because muscle gain is protein-limited, not calorie-limited, once you're in a surplus. Adding 1,000 calories of mostly sugar to an adequate diet builds some muscle and quite a lot of fat. Adding 60g of quality protein alongside a moderate carbohydrate load gives your body what it actually needs to build tissue.

Carbohydrate for Fuel, Not Just Calories

The carbohydrate blend in Pro Gainer replenishes muscle glycogen — the stored fuel heavy training depletes. It also raises insulin, which drives amino acid uptake into muscle.

The difference from Serious Mass is dose. Enough carbohydrate to fuel training and support recovery, without the very large load that makes a surplus hard to control.

20+ Vitamins and Minerals

Bulking diets built on calorie-dense foods often run short on micronutrients. Fortifying a product you're taking daily covers that ground — and micronutrient status affects energy metabolism, recovery and immune function, all of which matter more when you're training hard in a surplus.

Directions

Mix one serve with water or milk as directed on the label. Blending works better than shaking for a product this dense.

Take between meals or after training. Milk pushes the calories and protein higher if you need more; water keeps it controlled.

Start on a half serve for the first week if you're new to gainers — digestion needs time to adapt to the volume.

Allergens

Contains milk. May contain soy and egg. Check the label for flavour-specific allergen information.

Frequently Asked Questions

Which should I buy, Pro Gainer or Serious Mass?

Pro Gainer if you want a more controlled, protein-forward surplus and you're already eating reasonably. Serious Mass if you struggle to eat at all and need maximum calories in a glass.

Can I use it as a meal replacement?

Occasionally, yes — the protein and micronutrient content make it more complete than a straight protein shake. As a daily habit, whole food is better. Use it to supplement meals rather than replace them.

Will I get fat using a gainer?

Only if the surplus is too large or too prolonged. Pro Gainer's lower calorie load makes that easier to manage than a maximum-calorie product. Track your weight weekly and aim for around 0.25–0.5kg gain per week.

Do I still need a separate protein powder?

Probably not on the days you use Pro Gainer — 60g is a large protein dose. On non-gainer days, a standard whey protein is the cheaper way to hit your target.

How long does a 10lb tub last?

Depends on serve size, but expect several weeks at one serve a day. Check the label for the exact serve count in your flavour.