Optimum Nutrition Serious Mass – High‑Calorie Mass Gainer | 1,250 Calories, 50g Protein, 250g Carbs per Serving | Ultimate Weight Gain Formula
Experience the original and most trusted weight gain formula with Optimum Nutrition Serious Mass. Each serving delivers 1,250–1,260 calories, 50g of protein, and 250g+ carbohydrates to support muscle building, weight gain, and workout recovery. Formulated with creatine monohydrate (5g) for strength and power, glutamine (8g naturally occurring) to support recovery, and BCAAs (11g) & EAAs (24g). Enhanced with 19–25 vitamins and minerals to support overall health. Available in Chocolate Peanut Butter, Vanilla, Strawberry, Chocolate, and Banana flavors. Choose from 3lb (4 servings), 6lb (8 servings), or 12lb (16 servings) containers. Consult a healthcare professional before use. Contains milk, soy, egg, and gluten. Not for weight management. Contact us for wholesale orders. Delivery by air, land & sea worldwide. Standard & express shipment available.
Product Description
The Original High-Calorie Weight Gainer – Trusted by Hard Gainers Worldwide
When serious weight gain is the goal, it demands serious calories. Optimum Nutrition Serious Mass is the original and most trusted mass gainer, formulated specifically for athletes, bodybuilders, and hard gainers who struggle to consume enough calories through whole foods alone. With over 35 years of experience and distribution in more than 90 countries, Optimum Nutrition is the world’s leading sports nutrition brand, and Serious Mass is their highest‑calorie weight gain formula.
Each serving of Serious Mass is packed with over 1,250 calories, 50g of complete protein, and more than 250g of carbohydrates, plus added creatine monohydrate, glutamine, and 25 vitamins & minerals – everything you need to support muscle growth, replenish glycogen stores, and accelerate post‑workout recovery.
What Makes Serious Mass Different – The Original Mass Gainer
Unlike standard protein powders that focus on muscle repair alone, Serious Mass is a complete weight gain formula. Optimum Nutrition pioneered the category, and Serious Mass remains the industry benchmark:
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1,250–1,260 Calories per Serving (in Water): The highest caloric density among mainstream mass gainers, designed to help you achieve the calorie surplus essential for weight and muscle gain. When mixed with low‑fat milk, calories exceed 1,630.
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50g of Complete Protein: A multi‑source protein blend (whey protein concentrate, whey protein isolate, milk protein isolate, hydrolyzed whey, casein, and egg) provides a full spectrum of amino acids, including 11g of naturally occurring BCAAs (Branched‑Chain Amino Acids) and 24g of EAAs (Essential Amino Acids) to support muscle repair, recovery, and growth.
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250g+ Carbohydrates: A complex carbohydrate matrix (maltodextrin, oat, pea, and potato sources) helps fuel intense workouts, replenish depleted glycogen stores, and support sustained energy release. Contains no added sugar.
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5g Creatine Monohydrate: Enhances strength, power, and high‑intensity exercise performance by helping regenerate ATP (adenosine triphosphate), the primary energy source for muscle contractions.
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8g Naturally Occurring Glutamine: Supports immune function, gut health, and muscle recovery while helping to reduce muscle breakdown during periods of intense training.
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19–25 Vitamins & Minerals: Includes Vitamin A, C, D, E, B‑complex, Zinc, Calcium, Iron, Magnesium, and more. Vitamins A, C, E, and Zinc support immune health, while B‑vitamins help convert food into cellular energy.
Who Is Serious Mass For?
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Hard Gainers: Individuals who struggle to gain weight despite a high‑calorie diet.
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Athletes & Bodybuilders: Those engaged in intense resistance training who need extra calories and protein to support muscle growth and recovery.
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Anyone with a Fast Metabolism: People who burn calories quickly and need additional caloric support to maintain a surplus.
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Post‑Workout Recovery: The ideal shake immediately after training to kickstart recovery and replenish energy stores.
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Between‑Meal Supplement: Use as a convenient meal‑replacement‑style shake between whole‑food meals to increase daily caloric intake.
Quality & Purity – Optimum Nutrition‘s 35‑Year Legacy
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No Added Sugar: Sweetened with sucralose and acesulfame K – no sugar added to keep the formula clean.
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GMP Certified: Manufactured in Good Manufacturing Practice (GMP) certified facilities.
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Third‑Party Tested: Every batch is tested for purity, potency, and label accuracy.
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Informed‑Choice Certified (Select Batches): Many ON products are batch‑tested for banned substances, providing peace of mind for competitive athletes.
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Kosher Certified (Select Batches): Available in certain markets; contact us for availability.
⚠️ Important Dietary Warnings: Serious Mass is NOT gluten‑free, NOT lactose‑free, NOT suitable for vegans, and NOT suitable for ketogenic or Paleo diets. It contains milk, soy, egg, and wheat (gluten). It is suitable for vegetarians (contains milk and egg ingredients but no animal‑derived ingredients beyond dairy and egg).
⚙️ Product Specifications – Standard Formulation
Active Ingredients Per Serving (2 Heaping Scoops / approx. 334–340g)
| Parameter | Value (Typical) | % Reference Intake* |
|---|---|---|
| Calories | 1,250–1,260 kcal | – |
| Protein | 50g (≈15% per serving) | – |
| Total Carbohydrates | 250–253g | – |
| ─ Dietary Fiber | 4g | – |
| ─ Sugars | No added sugar | – |
| Total Fat | 4.5–5.5g | – |
| ─ Saturated Fat | 1–2g | – |
| Cholesterol | 70‑80mg | – |
| Sodium | 300–410mg | – |
| Creatine Monohydrate | 5g | – |
| Naturally Occurring BCAAs | 11g | – |
| Naturally Occurring EAAs | 24g | – |
| Naturally Occurring Glutamine | 8g | – |
Percent Daily Values may vary by flavor and region. Always refer to the product label for the most accurate information.
Vitamins & Minerals (Per Serving – Typical Profile)
| Vitamin / Mineral | Typical Amount | % Daily Value* |
|---|---|---|
| Vitamin A | 640–800 mcg | 80‑100% |
| Vitamin C | 60–80 mg | 75‑100% |
| Vitamin D | 4–5 mcg | 80‑100% |
| Vitamin E | 9–10 mg | 75‑80% |
| Vitamin K | 75 mcg | 100% |
| Thiamin (B1) | 0.86 mg | 78% |
| Riboflavin (B2) | 1.1 mg | 80% |
| Niacin (B3) | 13 mg | 80% |
| Vitamin B6 | 1.1 mg | 78% |
| Folate (B9) | 150 mcg | 75% |
| Vitamin B12 | 7.4 mcg | 294% |
| Biotin | 37 mcg | 75% |
| Calcium | Varies | – |
| Iron | Varies | – |
| Magnesium | Varies | – |
| Zinc | Varies | – |
Values based on 12lb container; may vary by serving size and region.
Protein Blend Composition
Serious Mass utilizes a proprietary multi‑source protein blend for a complete amino acid profile:
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Whey Protein Concentrate – Fast‑digesting, rich in BCAAs
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Whey Protein Isolate – Ultra‑pure, rapid absorption
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Milk Protein Isolate – Balanced whey‑to‑casein ratio
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Hydrolyzed Whey – Pre‑digested for even faster absorption
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Casein (Calcium Caseinate) – Slow‑digesting for sustained amino acid release
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Egg Albumin – High‑bioavailability complete protein
Ingredients (Chocolate Peanut Butter – Typical): Maltodextrin, Whey Protein Concentrate, Cocoa Powder (Processed with Alkali), Natural and Artificial Flavor, Sunflower and/or Soy Lecithin, Creamer (Sunflower Oil, Maltodextrin, Modified Food Starch, Dipotassium Phosphate, Tricalcium Phosphate, Tocopherols), Salt, Sucralose, Acesulfame Potassium.
Allergen Information: Contains milk, soy, and egg. May contain traces of wheat (gluten from wheat‑derived ingredients). Produced in a facility that processes gluten‑containing grains. Not suitable for individuals with celiac disease, lactose intolerance, or milk/soy/egg allergies.
📦 Available Packaging Options & Sizes
| Format | Net Weight | Servings | Container Type | Best For |
|---|---|---|---|---|
| 3 lb | 1.36 kg | 4 servings | Tub | Travel, trial, lighter usage |
| 6 lb | 2.72 kg | 8 servings | Tub | Regular home use, cost‑effective |
| 12 lb | 5.44 kg | 16 servings | Tub | Most popular – serious athletes, bulk value |
| 2 lb (select markets) | 0.9 kg | 2‑3 servings | Tub | Travel, sample size |
Wholesale Quantities
We supply all Optimum Nutrition Serious Mass product lines in large volumes to retailers, gyms, fitness centers, distributors, and food service operators:
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Wholesale Cases: 4‑pack, 6‑pack, 12‑pack of 6lb or 12lb tubs
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Full Pallets: Mixed flavors or single SKU
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20 ft / 40 ft Container Loads (FCL): For export and large‑scale distribution
Contact us for custom quotes, mixed pallets, and export pricing.
🍽 How to Use Optimum Nutrition Serious Mass
Preparation Instructions
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Standard Shake: Add 2 heaping scoops (approximately 334g) of powder to 400–500ml (13‑17 fl oz) of cold water, milk, or your preferred beverage. Shake, stir, or blend for 30‑45 seconds until smooth.
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For Maximum Calories: Use low‑fat milk instead of water – this increases the calorie count to over 1,630 calories per serving.
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Blended: For an even higher‑calorie shake, blend with ice, a banana, peanut butter, or oats.
When to Take Serious Mass
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Post‑Workout (Recommended): Consume immediately after training to rapidly replenish glycogen stores, deliver protein to fatigued muscles, and jumpstart recovery.
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Between Meals: Use as a convenient high‑calorie shake to increase daily caloric intake without preparing an additional solid‑food meal.
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Before Bed (for Mass Cycles): Consume 1‑2 hours before sleep for overnight muscle recovery and growth support.
Dosage Recommendations
| User Type | Daily Usage |
|---|---|
| Hard Gainer / Bulking Phase | 1 serving (2 scoops) daily, preferably post‑workout |
| Light User / Smaller Appetite | Start with 1 scoop (half serving) daily and gradually increase to a full serving over 1‑2 weeks |
| Extreme Bulking | 1 serving daily plus whole‑food meals to maintain a sustained calorie surplus |
Important:
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Hydration: Drink at least 2‑3 liters (8‑12 glasses) of water daily when using Serious Mass.
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Creatine Loading: No loading phase is required – the 5g creatine per serving is sufficient for maintenance. If you wish to load, use an additional 5g creatine supplement for the first 5‑7 days.
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Serving Adjustment: If a full serving causes digestive discomfort, start with half a serving (1 scoop, 165‑170g) and gradually increase.
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Not for Weight Management: This product is designed for weight gain and muscle building, not weight management.
⚠️ Important Safety Information & Warnings
| Warning | Details |
|---|---|
| Age Restriction | This product is only intended for healthy adults 18 years of age or older. |
| Not for Children | Keep out of reach of children. |
| Pregnancy & Nursing | Not for use by women who are pregnant, nursing, or trying to become pregnant. |
| Diabetes | This product is not suitable for diabetics due to the high carbohydrate content (250g+ per serving). |
| Kidney / Liver Disease | Consult a doctor before use if you have kidney or liver disease, hypertension, or any chronic condition. |
| Gluten Allergy / Celiac Disease | This product is not gluten‑free (contains wheat‑derived ingredients). |
| Lactose Intolerance | This product is not lactose‑free. Contains milk proteins and lactose. |
| Vegan Diet | This product is not suitable for vegans. Contains milk and egg ingredients. |
| Ketogenic / Paleo Diets | This product is not suitable for keto or Paleo diets due to high carbohydrate content. |
| Medication Interactions | Avoid if taking diuretics, NSAIDs, or blood pressure medication without medical advice. |
| Surgery | Discontinue use at least 2 weeks prior to scheduled surgery due to creatine content. |
| Adverse Reactions | Stop use immediately and consult a doctor if you experience palpitations, severe nausea, chest pain, or shortness of breath. |
| Maximum Daily Dose | Do not exceed 1 serving (2 scoops) per 24 hours. |
| Not a Meal Replacement | This product is a dietary supplement, not a complete meal replacement. It should be used alongside a balanced whole‑food diet. |
🧴 Storage & Shelf Life
| Condition | Duration | Instructions |
|---|---|---|
| Unopened | 24 months (check lot‑specific expiration) | Store in a cool, dry place below 25°C (77°F), away from direct sunlight and heat sources |
| Opened (Powder) | Use within 3‑6 months | Reseal the tub tightly after each use. Do not refrigerate (moisture causes clumping). Store in a clean, dry cupboard |
| Prepared Liquid Shake | 2 hours (room temp) / 24 hours (refrigerated) | Consume within 2 hours at room temperature. Refrigerated shakes may be stored up to 24 hours, but best used fresh. Do not freeze |
❓ Frequently Asked Questions (FAQs)
Q: How many calories are in Optimum Nutrition Serious Mass?
A: Each 2‑scoop serving provides 1,250–1,260 calories when mixed with water. Mixed with low‑fat milk, the calorie count exceeds 1,630 calories per serving.
Q: Is Serious Mass suitable for weight loss?
A: No. Serious Mass is specifically formulated for weight gain, muscle building, and calorie surplus. It is not intended for weight management or weight loss.
Q: How much creatine is in Serious Mass?
A: Each serving contains 5g of creatine monohydrate – the clinically researched dose for improving strength, power, and high‑intensity performance.
Q: Is Serious Mass gluten‑free?
A: No. Serious Mass is not gluten‑free. It contains maltodextrin and other ingredients derived from wheat and gluten‑containing grains. Not suitable for individuals with celiac disease or gluten sensitivity.
Q: Is Serious Mass lactose‑free?
A: No. Serious Mass contains whey protein concentrate, milk protein isolate, and casein, all of which contain lactose. Not suitable for individuals with lactose intolerance.
Q: Is Serious Mass suitable for vegetarians?
A: Yes, it is suitable for vegetarians. However, it is not suitable for vegans as it contains milk‑derived proteins and egg albumin.
Q: Is Serious Mass keto‑friendly?
A: No. With over 250g of carbohydrates per serving, this product will significantly exceed daily carbohydrate limits on a ketogenic diet.
Q: Does Serious Mass contain added sugar?
A: No added sugar. It is sweetened with sucralose and acesulfame K. The sugar content listed on the label comes naturally from lactose in the milk‑based ingredients.
Q: Can I take Serious Mass on non‑training days?
A: Yes. To maintain a calorie surplus and support muscle recovery, take 1 serving on non‑training days. For maintenance or lighter bulk phases, half a serving may be sufficient.
Q: How should I transition off Serious Mass?
A: Gradually reduce the serving size over 1‑2 weeks while increasing whole‑food caloric intake. If switching to a standard protein powder, allow for a 1‑2 week transition period.
Q: Is Serious Mass halal certified?
A: Halal certification varies by region and production batch. The original Optimum Nutrition Serious Mass formula does not contain pork or alcohol ingredients, but official Halal certification may not be present on all packs. Contact us for current certification status for your destination market.
Q: Why does the container look only partially full?
A: Contents are sold by weight, not by volume. Settling may occur during shipping and handling, which is normal. The net weight and number of servings are as stated on the label.
📜 HS Code & Tariff Classification
For accurate customs documentation and tariff calculation, we provide the correct Harmonized System codes.
| Code | Description |
|---|---|
| HS Code 2106.90 | Food preparations not elsewhere specified or included – used for finished protein powder blends, mass gainers, and dietary supplement products for retail sale |
| HS Code 2106.10 | Protein concentrates and textured protein substances – sometimes used for protein‑dominant blends |
Export Documents Available:
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Certificate of Analysis (COA) – per batch (including protein content, purity, heavy metals, microbiology)
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Certificate of Origin – upon request
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Commercial Invoice and Packing List with HS Code specification
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MSDS / SDS – available
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GMP Certificate – available upon request
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Kosher / Halal Certification – varies by batch; contact us for current status
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Allergen Statement – available
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Informed‑Choice Certification – available for select batches
All documentation provided as required by destination market regulations.
🌍 Global Supply & Delivery Information
We sell only top original quality products at very good and affordable prices. We have warehouses strategically located in the United States, Europe, and the Middle East, ensuring fast and reliable distribution across these regions.
We can ship worldwide via:
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✈️ Air Freight – Express & rapid delivery
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🚚 Land Transportation – Truck delivery within regions
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🚢 Sea Freight – Cost‑effective for bulk orders
Shipping Options Available:
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Standard International Shipping
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Express Worldwide Delivery
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Full Container Load (FCL) Supply
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Bulk Industrial Shipments
We deliver within the United States, Europe, and the Middle East, and we can ship to any destination globally. We support global exports with professional logistics coordination and secure delivery solutions worldwide.
For more inquiries or to place an order (samples, retail tubs, wholesale cases, full pallets, or container loads), please contact us.
We deliver by air, land, and sea — internationally. Standard and express shipment options available











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