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Optimum Nutrition (ON) Serious Mass — product pack

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Optimum Nutrition

Brand owned by Glanbia (Ireland) · about the brand

Optimum Nutrition (ON) Serious Mass

Veg Jain supplement
5.0 Moderate

Decode Label Safety Score

Nutrition · 40% 2.0/10
Ingredient safety · 30% 10.0/10
Processing · 20% 4.5/10
Marketing · 10% 5.2/10
How we got 5.0 Show
Weighted score 5.2/10
Score limited by a dominant nutrition concern. 5.0
Also flagged
Contains an intense artificial sweetener (named by INS code). Sweeteners are judged by name, and a protein powder is not exempt
Final score 5.0/10 · Moderate

Reviewed 6 times · Methodology v3.1 (updated 8 Oct 2026) — what changed

This protein supplement is primarily a source of protein and carbohydrates, with a comprehensive vitamin and mineral blend. The main concern is the high concentration of Maltodextrin, a rapidly absorbed carbohydrate that can lead to blood sugar spikes, making it less suitable for individuals managing blood sugar levels or those seeking a low-glycemic option. The use of an artificial chocolate flavor and the artificial sweetener Acesulfame Potassium (INS 950) also contribute to its ultra-processed nature, which some consumers may wish to avoid. While fortified with numerous essential micronutrients, its high carbohydrate content from Maltodextrin means it's best suited for individuals with high energy demands, such as athletes, rather than general dietary supplementation.

At a glance

From the declared label — not a lab test

Findings to weigh

Declared allergens Milk Matters if you have this allergy; check the pack’s own allergen statement. →

What’s favorable

  • Whey Protein Concentrate
  • Calcium Caseinate
  • Whey Powder
  • Emulsifier INS 322i
  • Cocoa powder
  • +27 more →

High in Maltodextrin; contains artificial flavor and sweetener.

This protein supplement is largely composed of Maltodextrin, a fast-digesting carbohydrate, which can cause rapid blood sugar increases. It also includes an artificial chocolate flavor and the artificial sweetener Acesulfame Potassium. While fortified with many vitamins and minerals, its ultra-processed nature and high carbohydrate content mean it's best for those with high energy needs, and less ideal for general health or blood sugar management.

Okay for: Athletes with high energy demands Individuals seeking rapid carbohydrate replenishment

Declared allergens: Milk

Milk· Whey Protein Concentrate, Calcium Caseinate

Relevant if you have this allergy or intolerance.

Based on the declared ingredient list. This is a risk only to people with the allergy, not a general-population safety issue, so it does not lower the safety score.

Concern breakdown What drives the score, concern by concern · score out of 10, higher = fewer concerns
Key risks: Nutrition profile

Concern breakdown

Score out of 10 · higher = fewer concerns

How this product performs on each concern we check for supplement. This is a breakdown of the same evidence behind the score above — not a separate verdict.

Artificial Sweeteners Significant concern · 3.5/10
Proprietary Blends & Dosing Moderate concern · 4.0/10
Excess Sodium & Salt Moderate concern · 5.0/10
Fillers & Additive Burden Moderate concern · 5.0/10
Banned & Adulterant Risk Minor concern · 6.5/10
Added & Hidden Sugar Minor concern · 7.5/10
Micronutrient Overdose No concern identified · 8.0/10
Stimulant Load No concern identified · 8.0/10
Artificial Colours & Dyes No concern identified · 8.0/10

Other audiences

Avoid
Not intended for children

This is an adult sports-nutrition supplement, formulated for adults for exercise and training. It is not intended for infants or young children.

Why the score is capped

Contains an intense artificial sweetener (named by INS code). Sweeteners are judged by name, and a protein powder is not exempt

Rule S-CAP-01 · Source: Declared ingredient list; EFSA and JECFA acceptable-daily-intake reviews of the named sweetener

What's good

Rich in high-quality protein sources (Whey Protein Concentrate, Calcium Caseinate)

Fortified with a comprehensive blend of essential vitamins and minerals

Contains Creatine Monohydrate and L-Glutamine, beneficial for athletic performance and recovery

Includes Medium Chain Triglycerides (MCTs) for quick energy

Watch out for

High Maltodextrin content (75%) can lead to rapid blood sugar spikes

Contains artificial flavor and artificial sweetener (Acesulfame Potassium)

Contains milk-derived ingredients, which are common allergens

Decode Label Analysis

The product contains a high percentage (75%) of Maltodextrin, a high-glycemic carbohydrate that can cause rapid spikes in blood sugar. This may not be suitable for individuals with diabetes, insulin resistance, or those aiming for stable blood glucose levels.

Contains artificial flavor (Chocolate) and artificial sweetener (Acesulfame Potassium, INS 950), which contribute to the ultra-processed nature of the product. While generally recognized as safe, some consumers prefer to avoid these ingredients.

Contains milk-derived ingredients (Whey Protein Concentrate, Calcium Caseinate, Whey Powder), which are common allergens. Individuals with dairy allergies or lactose intolerance should exercise caution.

Claim check

1 claim not supported by label data

Front-of-pack marketing claims checked against this product's actual ingredients and nutrition. "Can't verify" means the label does not provide enough information to check the claim — it is not the same as the claim being false.

!
"HIGH PROTEIN" Not supported by label data

Protein provides only 16.1% of energy — enough for a “source of protein” (10%) but below the 20% a “high protein” claim requires. (Judged on % of energy, not % by weight.)

Protein 15 g Energy 372 kcal 16.1% of energy from protein
?
"100% AUTHENTIC" Can't verify

Authenticity is a sourcing or certification claim that cannot be verified from the ingredient list or nutrition panel.

?
"MUSCLE BUILDING & WEIGHT GAIN FORMULA" Can't verify

Muscle building and weight gain are functional claims that cannot be verified from the ingredient list or nutrition panel alone.

?
"HELPS BUILD AND MAINTAIN MUSCLE" Can't verify

Building and maintaining muscle are functional claims that cannot be verified from the ingredient list or nutrition panel alone.

?
"HELPS FUEL INTENSE WORKOUTS" Can't verify

Fueling intense workouts is a functional claim that cannot be verified from the ingredient list or nutrition panel alone.

?
"POWDERED PROTEIN & CARBOHYDRATE DRINK MIX FOR HEALTHY ADULTS" Can't verify

The suitability for 'healthy adults' is a regulatory designation that cannot be checked from the ingredient list.

§
"FOOD FOR SPECIAL DIETARY USE - FOOD FOR WEIGHT GAIN" Regulatory designation

This is the product’s regulatory food-category / usage designation (e.g. a Food for Special Dietary Use classification or a mandated “use under medical advice” direction) — printed because regulation requires it, not a benefit claim. An ingredient list can’t confirm or deny it, s

✓
"1,243 CALORIES" Checks out

The product provides 1243 calories per serving (334g), which is derived from 372 kcal per 100g.

energy kcal 372 (per 100g) serving size: 334 g
✓
"HELPS BOOST CALORIE INTAKE" Checks out

The product provides 1243 calories per serving, which can help boost calorie intake.

energy kcal 372 (per 100g) serving size: 334 g
✓
"50g PROTEIN" Checks out

The product contains 50.1g of protein per serving (334g), derived from 15g per 100g.

protein g 15 (per 100g) serving size: 334 g
✓
"254g CARBS" Checks out

The product contains 254.4g of carbohydrates per serving (334g), derived from the energy and protein content.

energy kcal 372 (per 100g) protein g 15 (per 100g) fat g 1 (per 100g) serving size: 334 g
✓
"CHOCOLATE FLAVOUR" Checks out

The ingredient list includes cocoa powder and artificial flavor (chocolate).

Cocoa powder Artificial Flavor (Chocolate)

Read straight from the back-of-pack photo — quantities, sections and any disguised terms, so the small print can’t hide behind the marketing.

  • 1.
    Maltodextrin 75%
    Maltodextrin (75%)
  • 2.
    Protein Blend 18%
    Protein Blend (18%)
  • Whey Protein Concentrate within Protein Blend
  • Calcium Caseinate within Protein Blend
  • Whey Powder within Protein Blend
  • 3.
    Emulsifier INS 322i
    Lecithin (INS 322(i))
    (Emulsifier: INS 322i)
  • 4.
    Cocoa Powder
    Cocoa Powder (Processed with Alkali)
  • 5.
    Artificial Flavor (Chocolate) undisclosed flavouring
  • 6.
    Creatine Monohydrate
  • 7.
    L-Glutamine
  • 8.
    Vitamin and Mineral Blend
  • Sodium Chloride within Vitamin and Mineral Blend
  • Calcium Phosphate Tribasic within Vitamin and Mineral Blend
  • Magnesium Phosphate within Vitamin and Mineral Blend
  • Calcium Lactate within Vitamin and Mineral Blend
  • L-Ascorbic Acid within Vitamin and Mineral Blend
  • Zinc Sulfate within Vitamin and Mineral Blend
  • DL-Alpha-Tocopheryl Acetate within Vitamin and Mineral Blend
  • Nicotinamide within Vitamin and Mineral Blend
  • Ferric Pyrophosphate within Vitamin and Mineral Blend
  • Manganese Sulphate within Vitamin and Mineral Blend
  • Calcium D-Pantothenate within Vitamin and Mineral Blend
  • Pyridoxine Hydrochloride within Vitamin and Mineral Blend
  • Riboflavin within Vitamin and Mineral Blend
  • Thiamine Mononitrate within Vitamin and Mineral Blend
  • Retinyl Palmitate within Vitamin and Mineral Blend
  • Folic Acid within Vitamin and Mineral Blend
  • D-Biotin within Vitamin and Mineral Blend
  • Potassium Iodide within Vitamin and Mineral Blend
  • Chromium Chloride within Vitamin and Mineral Blend
  • Sodium Molybdate within Vitamin and Mineral Blend
  • Sodium Selenite within Vitamin and Mineral Blend
  • Ergocalciferol within Vitamin and Mineral Blend
  • Cyanocobalamin within Vitamin and Mineral Blend
  • 9.
    L-Choline Bitartrate
  • 10.
    Sweetener INS 950
    Acesulfame potassium (INS 950)
    Sweetener (INS 950)
  • 11.
    Inositol
  • 12.
    Medium Chain Triglycerides Powder

In label order — normally largest quantity first. Select a row for the full write-up and sources.

These are major food allergens named on the ingredient list. They are a risk only to people allergic to them — not a general-population safety issue — so they do not lower the safety score. Anyone with the allergy should avoid this product, and check the pack’s own allergen statement.

Milk Allergen on the label: Whey Protein Concentrate, Calcium Caseinate, Whey Powder
Allergen

The label declares each of these as a blend and then lists what is in it. The components appear in the groups above on their own merits, so the blend itself is shown here rather than counted a second time.

Learn More

Google Wikipedia EWG Skin Deep Open Food Facts
Nutrition (per 100 g) Serving: 334 g (About 2 Scoops)
Energy 372 kcal
Protein 15 g
Carbohydrate 76 g
Total Sugars 6 g
Added Sugars 0 g
Total Fat 1 g
Saturated Fat 0.6 g
Trans Fat 0 g
Sodium 163 mg
Cholesterol 43 mg
Potassium 130 mg
Vitamin A 37 µg
Thiamine 0.04 mg
Riboflavin 0.06 mg
Niacin 0.6 mg
Folic Acid 20 µg
Vitamin B6 0.1 mg
Vitamin B12 0.6 µg
Biotin 9 µg
Pantothenic Acid 0.6 mg
Vitamin C 1 mg
Vitamin D 2 µg
Vitamin E 1 mg
Calcium 171 mg
Chromium 10 µg
Iron 0.3 mg
Iodide 15 µg
Magnesium 15 mg
Manganese 0.2 mg
Molybdenum 13 µg
Phosphorus 108 mg
Selenium 12 µg
Zinc 0.6 mg
Creatine 1 g
L-Glutamine 0.3 g
Choline 75 mg
Inositol 75 mg

Colour shows the per-100g level (green = low, amber = moderate, red = high), from the product's label.

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Optimum Nutrition

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What are the ingredients in Optimum Nutrition (ON) Serious Mass?

The label of Optimum Nutrition (ON) Serious Mass lists 38 ingredients, in label order: Maltodextrin, Protein blend, Whey Protein Concentrate, Calcium Caseinate, Whey Powder, Emulsifier INS 322i, Cocoa powder, Artificial Flavor (Chocolate), Creatine Monohydrate, L-Glutamine, Vitamin and Mineral Blend, Sodium Chloride, Calcium Phosphate Tribasic, Magnesium Phosphate, Calcium lactate, L-Ascorbic Acid, Zinc sulfate, DL-Alpha-Tocopheryl Acetate, Nicotinamide, Ferric pyrophosphate, Manganese sulphate, Calcium D-Pantothenate, Pyridoxine hydrochloride, Riboflavin, Thiamine Mononitrate, Retinyl Palmitate, Folic acid, D-Biotin, Potassium iodide, Chromium Chloride, Sodium molybdate, Sodium selenite, Ergocalciferol, Cyanocobalamin, L-Choline Bitartrate, Sweetener INS 950, Inositol, Medium Chain Triglycerides Powder. Flagged by the analysis: Maltodextrin, Artificial Flavor (Chocolate), Sweetener INS 950.

Is Optimum Nutrition (ON) Serious Mass safe to eat?

Optimum Nutrition (ON) Serious Mass scores 5.0/10 on Decode Label (Moderate). This protein supplement is largely composed of Maltodextrin, a fast-digesting carbohydrate, which can cause rapid blood sugar increases. It also includes an artificial chocolate flavor and the artificial sweetener Acesulfame Potassium. While fortified with many vitamins and minerals, its ultra-processed nature and high carbohydrate content mean it's best for those with high energy needs, and less ideal for general health or blood sugar management.

Why does Optimum Nutrition (ON) Serious Mass score 5.0/10?

Flagged in the score: High Maltodextrin content (75%) can lead to rapid blood sugar spikes. Also noted: Contains artificial flavor and artificial sweetener (Acesulfame Potassium). Contains milk-derived ingredients, which are common allergens.

Who should avoid Optimum Nutrition (ON) Serious Mass?

The points the analysis notes are most relevant to: Diabetes or blood sugar management concerns; Sensitivity to artificial sweeteners; Desire to avoid ultra-processed ingredients; Milk allergy / lactose intolerance.

Does Optimum Nutrition (ON) Serious Mass contain allergens?

Yes — the ingredient list contains milk (Whey Protein Concentrate, Calcium Caseinate and Whey Powder). Check the allergen statement on the pack too if you have a diagnosed allergy.

Does Optimum Nutrition (ON) Serious Mass contain milk?

Yes — the ingredient list names Whey Protein Concentrate, Calcium Caseinate and Whey Powder. People with milk allergy / lactose intolerance should treat it as containing milk, and check the allergen statement on the pack too.

How much sugar is in Optimum Nutrition (ON) Serious Mass?

6 g of total sugar per 100 g. The label declares 0 g of that as added sugar per 100 g.

Are the claims on the Optimum Nutrition (ON) Serious Mass pack accurate?

Decode Label checked 12 claims against the ingredient list and nutrition panel. "HIGH PROTEIN" — misleading. "100% AUTHENTIC" — can't be verified from the label. "MUSCLE BUILDING & WEIGHT GAIN FORMULA" — can't be verified from the label.

Is Optimum Nutrition (ON) Serious Mass vegetarian?

Optimum Nutrition (ON) Serious Mass is marked vegetarian.

Answers are generated from this product's own Decode Label analysis — the score, the ingredient list and the label claims shown above. Always check the pack itself for allergen and dietary information.

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About this analysis: Based on declared label information and available evidence. Decode Label does not independently laboratory-test products, and a score is not a regulatory determination or medical advice.

Disclaimer: Safety scores are Decode Label-generated assessments based on publicly available regulatory data (FSSAI, WHO, EFSA, IARC) and peer-reviewed research. They are not a substitute for professional medical advice, and they are not a regulatory determination, a laboratory safety certification or a medical diagnosis. Ingredient safety can vary by individual health conditions, concentration, and usage context. Decode Label is an independent information service and scores every brand by the same rules. No brand pays for or influences its score. Our founder also founded the personal-care brand Botani Bestie (see our story); its products are scored exactly like everyone else's. Data limitations: This assessment is based on the information declared on the product label and the evidence sources above — Decode Label does not independently laboratory-test this product. Ingredient concentrations, sourcing and manufacturing can vary between batches and are not always disclosed. A finding that is not shown here means it was not identified from the available label information, not that it has been ruled out.

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