High Protein Muscle Building & Weight Gain Formula* 50 g Protein ■ Helps Build and Maintain Muscle* 1,250 Calories Helps Boost Calorie Intake 250 g Carbs Helps Fuel Intense Workouts Artificially Flavored Strength Training Supports Performance Support Weight Gain Goals Authentic Optimum Nutrition Product Informed Choice - We Test, You Trust Regularly Tested for Banned Substances Serious Mass ™ is designed to provide serious calories, protein and carbohydrates - making this a convenient way to get extra calories throughout your day. A Global Leader of Weight Gainers Serious weight gain requires Serious calories. However, those who heed the extra calories most often have the toughest time consuming enough of them. For many aspiring to be bigger, having a highly-active metabolism, weaker appetite or an on-the-run lifestyle can make it a real challenge to consume enough calories through whole foods alone. With SERIOUS MASS™, you've got nothing to lose and lots to gain. It's time to stop thinking small; get SERIOUS - SERIOUS MASS™. Why Serious Mass ™ ? 50 g of protein to support muscle building and recovery.* 1,250 calories to support a calorie surplus for weight and muscle building.* 250 g of carbohydrates to support fueling of intense workouts and aid in replenishment of glycogen stores. 5 g of creatine monohydrate to support strength, power, and performance.* Naturally occurring Glutamine 8 g, Branched Chain Amino Acids 11 g and Essential Amino Acids 24 g Good source of 19 vitamins and minerals Vitamins A, C, E, and zinc help support a healthy immune system B vitamins help convert food to cellular energy Optimum Nutrition ® has been trusted to provide the highest quality in post-workout recovery, pre-workout energy, and on-the-go sports nutrition for over 30 years and in 90+ countries. After careful supplier selection, each ingredient is tested to assure exceptional purity, potency and composition. We hold ourselves to the highest production standards, all so you can unlock your body's full potential. Informed Choice We Trust - You Trust: Informed Choice is a quality assurance program for sports nutrition products. The program certifies that nutritional supplements that bear the informed Choice logo are regularly tested for banned substances by the world class sports anti-doping lab, LGC limited. ■ See supplement facts for Sodium and Cholesterol content. *When taken in addition to normal calorie intake and regular weight resistance training
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High Protein Muscle Building & Weight Gain Formula* 50 g Protein ■ Helps Build and Maintain Muscle* 1,250 Calories Helps Boost Calorie Intake 250 g Carbs Helps Fuel Intense Workouts Artificially Flavored Strength Training Supports Performance Support Weight Gain Goals Authentic Optimum Nutrition Product Informed Choice - We Test, You Trust Regularly Tested for Banned Substances Serious Mass ™ is designed to provide serious calories, protein and carbohydrates - making this a convenient way to get extra calories throughout your day. A Global Leader of Weight Gainers Serious weight gain requires Serious calories. However, those who heed the extra calories most often have the toughest time consuming enough of them. For many aspiring to be bigger, having a highly-active metabolism, weaker appetite or an on-the-run lifestyle can make it a real challenge to consume enough calories through whole foods alone. With SERIOUS MASS™, you've got nothing to lose and lots to gain. It's time to stop thinking small; get SERIOUS - SERIOUS MASS™. Why Serious Mass ™ ? 50 g of protein to support muscle building and recovery.* 1,250 calories to support a calorie surplus for weight and muscle building.* 250 g of carbohydrates to support fueling of intense workouts and aid in replenishment of glycogen stores. 5 g of creatine monohydrate to support strength, power, and performance.* Naturally occurring Glutamine 8 g, Branched Chain Amino Acids 11 g and Essential Amino Acids 24 g Good source of 19 vitamins and minerals Vitamins A, C, E, and zinc help support a healthy immune system B vitamins help convert food to cellular energy Optimum Nutrition ® has been trusted to provide the highest quality in post-workout recovery, pre-workout energy, and on-the-go sports nutrition for over 30 years and in 90+ countries. After careful supplier selection, each ingredient is tested to assure exceptional purity, potency and composition. We hold ourselves to the highest production standards, all so you can unlock your body's full potential. Informed Choice We Trust - You Trust: Informed Choice is a quality assurance program for sports nutrition products. The program certifies that nutritional supplements that bear the informed Choice logo are regularly tested for banned substances by the world class sports anti-doping lab, LGC limited. ■ See supplement facts for Sodium and Cholesterol content. *When taken in addition to normal calorie intake and regular weight resistance training
SKU
3-66476
Brand
Optimum Nutrition
Category
health / sports-nutrition / protein / mass-gainers
Variants
1
Customer reviews
5.0
verified purchase
とても素晴らしい！
Mình khá gầy nên đã mua sản phẩm này với mục tiêu tăng cân lành mạnh. Sau khoảng 1 tháng sử dụng đều đặn (2 lần/ngày kết hợp ăn uống đầy đủ), mình đã tăng được gần 2 kg. Bột rất dễ pha, vị không quá ngọt, uống không bị ngấy và cũng không gây khó chịu cho dạ dày.
Điều mình thích nhất là lượng calo và protein cao, rất phù hợp với những người khó tăng cân hoặc bận rộn không ăn đủ bữa. Mình chia thành nhiều lần uống trong ngày nên cơ thể hấp thu khá tốt.
Nếu bạn đang muốn tăng cân một cách từ từ và kết hợp với chế độ ăn hợp lý thì mình nghĩ đây là một sản phẩm rất đáng để thử. Mình chắc chắn sẽ mua lại.
7/18/2026
5.0
verified purchase
I haven't used it yet, but it looks fine from the outside. I'll see what the response is after using it.
4/14/2026
5.0
verified purchase
Quality is super! The ingredients are great! Size arranged! What you need! Performance is felt!
the product arranged, perfectly packed, the effect is definitely there! I will order more! Just as quickly delivered
3/21/2026
5.0
verified purchase
Gains
Start taking this supplement I have been way gain gaining weight and gaining a lot of muscle. Try it out!
2/4/2026
5.0
verified purchase
Good
Quality is really good and the taste is not bad when mixed with milk the size is good the package came without damages the ingredients are good and composition is good
1/26/2026
5.0
verified purchase
IHerb offers a wide range of authentic products with fast international shipping. The packaging is always secure, and their prices are reasonable. Customer service is helpful, and the site is easy to use. Highly recommended for health and wellness shopping. IHerb offers a wide range of authentic products with fast international shipping. The packaging is always secure, and their prices are reasonable. Customer service is helpful, and the site is easy to use. Highly recommended for health and wellness shopping. The size also is correct and the have chocolate taste with hight quality ingredients
11/25/2025
5.0
verified purchase
ممتاز!
I gain alomst two kilo within like a week but the taste abit not that much good
11/8/2025
5.0
verified purchase
Amazing
This my third time ordering it
I don’t have to to explain more
10/4/2025
5.0
verified purchase
Прекрасно!
Excellent product! Fast delivery and reasonable price for this quality! I liked the taste and its effect. I will be glad to buy it again! I buy monthly in this store and almost always happy with my purchases! Unfortunately, in reality there are not many stores like iherb on this site it is easy to find and choose the right product and read reviews from other buyers Excellent product! Fast delivery and reasonable price for this quality! I liked the taste and its effect. I will be glad to buy it again! I buy monthly in this store and almost always happy with my purchases! Unfortunately, in reality there are not many stores like iherb on this site it is easy to find and choose the right product and read reviews from other buyers
7/6/2025
5.0
verified purchase
Serious Mass Chocolate Peanut Butter
The quality of Serious Mass is outstanding, made by a reputable brand known for its effective sports nutrition supplements. The ingredients list is comprehensive and thoughtfully formulated, featuring a mix of whey protein concentrate and isolate for fast and sustained protein delivery. The taste of the Chocolate Peanut Butter flavor is rich and indulgent—an enjoyable mix of creamy chocolate and nutty peanut butter that makes drinking your calories a treat rather than a chore.
