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251K Lincoln Road

Waitakere 0610

22B Cavendish Drive

Manukau 2104

4 Aranui Road

Auckland 1060

1 Wagener Place

Auckland 1025

Optimum Nutrition

Optimum Nutrition Serious Mass 12lb

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Optimum Nutrition Serious Mass 12lb

If you're ready to get serious about packing on big-time muscle, then you need Serious Mass Weight Gainer.


What is Serious Mass?

ON Serious Mass is a well-rounded weight gaining formula with a whopping 1,250 calories per serving. But it's not just a calorie bomb -- there's also 50 grams of protein, creatine, glutamine, zero added sugar, and much more.


ON Serious Mass features:

  • Loaded with calories at 1,250 per serving
  • 50g blend of whey and casein protein
  • 25g vitamin and mineral complex
  • Creatine & Glutamine for extra strength and recovery
  • No added sugar!


Use ON Serious Mass to pack on the muscle mass you've always desired. Mix two scoops with 700mL of water, or for a thicker consistency, use milk instead. Take one full serving per day.


Nutrition Information


Optimum Nutrition Serious Mass 12lb Nutrition Info


*While strives to ensure the accuracy of its product images and information, some manufacturing changes to packaging and/or ingredients may be pending update on our site. Although items may occasionally ship with alternate packaging, freshness is always guaranteed. We recommend that you read labels, warnings and directions of all products before use and not rely solely on the information provided by .

*Always consult with a qualified healthcare professional prior to beginning any diet or exercise program or taking any dietary supplement. The content on our website is for informational and educational purposes only and is not intended as medical advice or to replace a relationship with a qualified healthcare professional.

*All specials and deals are while stocks last only. No rain checks.

*Not all stock is carried at all stores. Message us first to avoid disappointment.

Customer Reviews
4.9 Based on 13 Reviews
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One of the best

Have been using this for a good year and is my one and only choice. Overall, not as sweet as other brands used. Great gainer for my body type.

Ross M.
New Zealand New Zealand

Optimum Nutrition Serious Mass 12lb excellent product

Product lives up to what it claims, very easy to digest, tastes great and most importantly, u will put on the mass

Imran P.
New Zealand New Zealand

Very good taste delicious

Very satisfied

Kross A.
New Zealand New Zealand

Great flavor and not too sweet!

Thankful for prompt delivery of product. Very good on the digestive side of things. Overall, great between meals to keep metabolism working and have another serve before bedtime so that my body is being rejuvenated whilst asleep. Ready for next busy day. Recommend this product.

Ross M.
New Zealand New Zealand


Packed on the pounds with this one.

martin m.
New Zealand New Zealand
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