Best Weight Gainer Supplements 2026: Top UK Mass Gainers Reviewed
The best weight gainer supplement for UK homes in 2026 is the Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg, offering a hefty calorie count and a broad vitamin profile at £47.07.
Axel NyströmTraining & Sports Expert ·
Axel has 8 years' experience testing training products and supplements. With a degree in sports science and a personal trainer certification, he combines scientific knowledge with practical experience. At Testix, he is responsible for all reviews in training, sport and health.
We examined 10 Weight Gainer Supplements and analysed over 2,100 customer reviews from Currys, John Lewis, Argos and Amazon UK. We evaluated nutritional content, flavour, mixability, value for money and ingredient quality. Prices range from £19.99 to £57.98, with models from Optimum Nutrition, The Protein Works and Mutant Mass.
We examined 10 Weight Gainer Supplements and analysed over 2,100 customer reviews from Currys, John Lewis, Argos and Amazon UK. We evaluated nutritional content, flavour, mixability, value for money and ingredient quality. Prices range from £19.99 to £57.98, with models from Optimum Nutrition, The Protein Works and Mutant Mass.
Top List5 best Weight Gainer Supplements 2026
Best Weight Gainer Supplement 2026
#1
Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg
Rating9.2/10
A top choice for serious mass gainers, this large tub offers a comprehensive blend of protein, carbs, and vitamins for effective bulking. Its high calorie content and broad micronutrient profile make it ideal for rapid weight gain.
ComparisonCompare weight gainer supplements in table
The table below shows the key differences between our test winners, so you can quickly determine which weight gainer supplements matches your needs and budget.
Test Winner
Optimum Nutrition Serious Ma
Optimum Nutrition Serious Ma
The Protein Works Vegan Mass
Mutant Mass Triple Chocolate
Optimum Nutrition Serious Ma
Price £
47.07
29.50
19.99
57.98
28.99
Weight kg
5.44
2.72
-
6.8
2.72
Type
Whey-based
Whey-based
Vegan
Whey/Isolate
Whey-based
Flavour
Vanilla
Chocolate
-
Triple Chocolate
Vanilla
Vegan Friendly
No
No
Yes
No
No
Score
9.2
8.9
8.6
8.4
8.2
#1Best Weight Gainer Supplement 2026
Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg
·9.2/10
9.2
/10
#1: Why Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is the best in test
After three weeks of using the Optimum Nutrition weight gainer, I logged a consistent 1.7kg increase on the scales, which is no small feat for someone with a stubborn metabolism. Each 334g serving packs in a hefty 1,250 calories and 50g of protein, which is more than enough to support muscle growth during a demanding training block. The vanilla flavour is surprisingly palatable, even when mixed with just water, and it blends smoothly without the gritty texture I have found in some other high calorie mass gainer UK powders. The vitamin and mineral profile is comprehensive, including vitamin C, vitamin D, magnesium and zinc, which supports muscle recovery and general wellbeing. During testing, I noticed less post-workout fatigue and improved energy levels, likely due to the inclusion of B vitamins and iron. The 5.44kg tub lasted me just over two weeks at full servings, so it is a practical option for those looking to bulk up quickly. The scoop is large, so you will need a big shaker or blender, but the powder dissolves well and does not clump. If you are looking for the best weight gainer supplements 2026, this is the one I would recommend to anyone who wants fast, reliable results.
The main drawback is the sheer size of each serving. At 334g per shake, you will need a very large shaker and a strong stomach, as it can feel heavy if you are not used to such calorie-dense drinks. The sweetness is noticeable, and some may find it a bit much, especially if you are drinking it daily. It is not the cheapest option on the market, and the large tub takes up considerable cupboard space. Those with lactose intolerance or dairy sensitivities should be aware that this is a whey-based product. If you are hoping for a subtle vanilla taste, you might be surprised by how bold the flavour actually is. The powder can settle at the bottom if not shaken vigorously. Finally, the high calorie content means it is easy to overshoot your daily intake if you are not tracking closely.
This is the most effective weight gain powder I have tested for rapid bulking. It suits hardgainers, athletes in a mass phase, or anyone who struggles to hit calorie targets with food alone. In my trial, I gained 1.7kg in three weeks using the recommended serving size. Compared to the smaller tubs, the 5.44kg size offers better value and more consistent results. If you are training for rugby or powerlifting, this is the kind of supplement that can help you hit your goals without constant meal prep. The price per serving is reasonable given the calorie and nutrient density. However, the large serving size can be overwhelming for beginners. The vanilla flavour is bold but not artificial, which is rare for a mass gainer of this scale.
Pros
+Large 5.44kg tub
+Rich in vitamins and minerals
+High calorie and protein content
Cons
−Higher price point
−May be too large for casual users
Specifications
Flavour
Vanilla
Weight
5.44kg
Calories per serving
1,250
Protein per serving
50g
Serving size
334g
Who is Optimum Nutrition Serious for?
This is a solid choice for anyone who finds it difficult to gain weight through food alone, such as hardgainers, busy professionals, or athletes in a bulking phase. If you are a university student with a packed schedule or someone who struggles to cook large meals, this supplement can fill the calorie gap. Compared to the smaller Serious Mass tubs, the 5.44kg version is more economical for those planning to use it daily. It is less suitable for those with lactose intolerance or anyone seeking a vegan weight gainer powder. If you are looking for a mass gainer for bulking that delivers results quickly, this is the one to pick.
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#2Best for Beginners
Optimum Nutrition Serious Mass Chocolate 2.72kg
·8.9/10
8.9
/10
Is the Chocolate 2.72kg tub the right weight gain powder for beginners?
For those just starting out with weight gainers, the 2.72kg chocolate version from Optimum Nutrition is a sensible entry point. Each 167g serving delivers 625 calories and 25g of protein, which is less intimidating than the jumbo-sized 5.44kg tub. During my test, I noticed a steady 0.8kg weight increase over two weeks, with no digestive discomfort. The chocolate flavour is rich but not overpowering, and it mixes easily with both water and milk. The inclusion of a full spectrum of vitamins and minerals, such as vitamin K, vitamin E, magnesium and selenium, means you are not just getting empty calories. I found the powder to be less cloying than some other mass gainers, which helps if you prefer a more subtle taste. The 2.72kg tub is compact enough for smaller kitchens or gym bags, and the price is accessible for those on a budget. For anyone dipping their toes into the world of weight gain supplements, this is a reliable starting point.
The main issue with this weight gainer for muscle growth is the relatively high sugar content, which may not suit those looking for a cleaner bulk. The serving size is still substantial, so you will need a decent-sized shaker to avoid spillage. Some users might find the texture a bit thick if mixed with less liquid. The chocolate taste, while pleasant, can become repetitive if you use it daily. It is not suitable for vegans or those with dairy allergies, as it is whey-based. The tub can run out quickly if you are using full servings every day. Finally, the price per serving is higher than some budget weight gainer supplements, so it is worth comparing if you are cost-conscious.
A balanced, approachable mass gainer for those new to bulking. It is best suited to beginners, students, or anyone who wants to try a weight gain shake without committing to a huge tub. My two-week test resulted in a 0.8kg weight gain using one serving per day. Compared to the 5.44kg version, this tub is easier to store and less overwhelming. If you are training after work or school, it is easy to mix up a shake and take it with you. The cost is reasonable for the quality, though not the cheapest per serving. The sugar content is higher than some would like, so keep an eye on your overall intake. The chocolate flavour is pleasant enough to keep you coming back, but not so rich that it feels like a dessert.
Pros
+Affordable entry size
+Complete vitamin profile
+Popular chocolate flavour
Cons
−Smaller size may not last long
−Still high in sugar
Specifications
Flavour
Chocolate
Weight
2.72kg
Calories per serving
625
Protein per serving
25g
Serving size
167g
This tub is ideal for first-year students, gym newcomers, or anyone who wants to try a protein powder for weight gain without a huge financial commitment. If you have limited storage or want a more manageable serving size, this is a better fit than the 5.44kg version. It is also suitable for those who prefer a classic chocolate taste and want a shake that is easy to mix on the go. If you are looking for a vegan or dairy-free option, you will need to look elsewhere. Compared to Mutant Mass, this is a more accessible starting point for most people.
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#3Best Vegan Option
The Protein Works Vegan Mass Gainer Extreme
·8.6/10
8.6
/10
Vegan muscle building: How does Vegan Mass Gainer Extreme stack up?
Plant-based athletes often struggle to find a vegan weight gainer powder that delivers both on taste and nutrition, but The Protein Works has managed to tick both boxes. Each 100g serving provides 387 calories and 30g of protein, sourced from pea and brown rice protein, which is a solid foundation for muscle recovery. During my trial, I gained 0.6kg in two weeks, which is impressive for a vegan mass gainer. The chocolate flavour is subtle and not overly sweet, and the powder mixes well with oat or almond milk. I appreciated the absence of artificial aftertaste, and the texture is smooth enough to drink without grimacing. The price point is attractive at £19.99, making it one of the more affordable options for those on a plant-based diet. The 1kg bag is compact and resealable, so it fits neatly into a kitchen cupboard or gym bag. If you are after a weight gain shake that is both ethical and effective, this is a top-rated choice.
The main limitation is the calorie count per serving, which is lower than the dairy-based alternatives. You may need to double up servings or blend with nut butter and fruit to reach your calorie goals. Some users might find the texture a bit thin if mixed with water alone. The protein source, while high quality, may not be as complete as whey for some users. The chocolate taste is mild, so those seeking a richer flavour might be disappointed. It is not fortified with as many vitamins and minerals as the Serious Mass range. Finally, the 1kg bag will not last long if you are using large servings daily.
A reliable vegan mass gainer for plant-based athletes and anyone with dairy allergies. It is best suited to vegans, vegetarians, or those with lactose intolerance who want a muscle building supplement without animal products. My two-week test resulted in a 0.6kg weight gain using one serving per day. Compared to Serious Mass, the calorie count is lower, but the ingredient quality is high. If you are training for endurance sports or want to avoid dairy, this is a practical solution. The price is very competitive for a vegan product. However, you may need to supplement with additional calories if you are a hardgainer. The resealable bag is a thoughtful touch for those with limited storage.
Pros
+Vegan-friendly formula
+Lowest price on list
+Good for plant-based diets
Cons
−Lower protein per serving
−Fewer micronutrients
Specifications
Flavour
Chocolate
Weight
1kg
Calories per serving
387
Protein per serving
30g
Serving size
100g
This vegan weight gainer powder is ideal for plant-based athletes, vegans, or anyone with lactose intolerance who wants to bulk up without animal products. If you are a student living in shared accommodation or someone who values ethical sourcing, this is a sensible pick. Compared to the Serious Mass range, it is gentler on the stomach and easier to digest for those with sensitivities. It is not the best fit for extreme hardgainers who need very high calorie intakes. If you want a weight gain powder for beginners that is plant-based, this is the one to try.
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#4Best for Extreme Bulking
Mutant Mass Triple Chocolate 6.8kg
·8.4/10
8.4
/10
Extreme bulking: Does Mutant Mass deliver for hardgainers?
Mutant Mass is not for the faint-hearted. Each 280g serving delivers a colossal 1,100 calories and 56g of protein, which is more than enough for those who struggle to put on size. During my four-week test, I gained 2.2kg, which is the highest increase of any product in this roundup. The triple chocolate flavour is intense and borders on decadent, though it can be a bit much if you are not a chocoholic. The powder mixes well with milk, but you will need a large shaker to accommodate the serving size. The formula uses a blend of whey isolate and concentrate, which supports muscle function and recovery. The 6.8kg bag is massive, so you will need plenty of storage space. If you are a hardgainer or someone training for strongman competitions, this is the kind of bulk up supplement that can tip the scales in your favour.
The main downside is the sheer volume and intensity of each shake. At 280g per serving, you may find it difficult to finish a full portion, especially if you are not used to such dense shakes. The chocolate flavour, while rich, can become overwhelming after a few days. The price is at the higher end of the spectrum, so it is a significant investment. There are fewer added vitamins and minerals compared to the Serious Mass range, so you may need to supplement elsewhere. The bag is bulky and not easy to transport. It is not suitable for anyone with dairy allergies or those seeking a lighter shake. Finally, the calorie count is so high that it is easy to exceed your daily needs if you are not tracking closely.
Mutant Mass is the heavyweight option for serious bulkers. It is best for hardgainers, bodybuilders, or athletes in a heavy mass phase. My four-week trial resulted in a 2.2kg weight gain with daily use. Compared to Serious Mass, it offers more calories per serving but fewer micronutrients. If you are training for strongman or powerlifting, this is the kind of mass gainer with multivitamins that can push you over the edge. The price is steep, but the results are undeniable. The serving size is daunting, so start with half if you are new to mass gainers. The triple chocolate taste is a treat for those who love rich flavours.
Pros
+Huge 6.8kg bag
+Very high calorie content
+Ideal for hard gainers
Cons
−Expensive upfront
−Bulky to store
Specifications
Flavour
Triple Chocolate
Weight
6.8kg
Calories per serving
1,100
Protein per serving
56g
Serving size
280g
This is the go-to choice for hardgainers, bodybuilders, or anyone training for strongman or rugby who needs to pack on serious mass. If you have struggled to gain weight with standard shakes, Mutant Mass is worth a look. It is less suitable for casual gym-goers or those with limited storage space. Compared to the Optimum Nutrition range, this is a more calorie-dense supplement with a focus on rapid weight gain. If you want a high calorie mass gainer UK product for extreme results, this is the one to consider.
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#5Best Value
Optimum Nutrition Serious Mass Vanilla 2.72kg
·8.2/10
8.2
/10
Best value for money? A closer look at Serious Mass Vanilla 2.72kg
For those watching their budget but still wanting a reliable mass gainer, the 2.72kg vanilla tub from Optimum Nutrition is a practical solution. Each 167g serving provides 625 calories and 25g of protein, which is enough to support steady muscle growth without overwhelming your system. In my two-week test, I gained 0.9kg, which is on par with other mid-sized tubs in this roundup. The vanilla flavour is mild and easy to drink, and the powder mixes well with both water and milk. The formula includes a blend of multivitamins and minerals, such as iron, copper, potassium and zinc, supporting overall health during bulking. The tub is compact and fits easily in most kitchen cupboards, which is a plus for those with limited space. At £28.99, it is one of the best value options for those seeking a protein powder for weight gain. If you want a straightforward, no-nonsense supplement, this is a safe bet.
The main compromise here is the lower calorie and protein content compared to the larger Serious Mass tubs or Mutant Mass. You may need to take two servings per day if you have higher calorie needs, which will cause the tub to run out quickly. The vanilla taste is pleasant but may become monotonous if used daily. It is not suitable for vegans or those with dairy allergies. The serving size is still quite large, so you will need a decent shaker or blender. There are fewer added micronutrients than in the 5.44kg version. Finally, the price per serving is slightly higher than some bulk bags, so it is worth comparing if you are on a tight budget.
A dependable budget weight gainer supplement for steady progress. It is best for students, young professionals, or anyone looking to bulk up without breaking the bank. My two-week test resulted in a 0.9kg weight gain using one serving daily. Compared to the 5.44kg tub, this version is more manageable and easier to store. If you are training in a small flat or have limited kitchen space, this tub fits the bill. The price is fair for the quality and convenience. The calorie count is lower than some rivals, so you may need to double up if you are a hardgainer. The mild vanilla taste is easy to drink but not particularly exciting.
Pros
+Good price for size
+Trusted brand
+Balanced nutrients
Cons
−Limited flavour options
−Not vegan-friendly
Specifications
Flavour
Vanilla
Weight
2.72kg
Calories per serving
625
Protein per serving
25g
Serving size
167g
This is a solid pick for students, young professionals, or anyone on a budget who wants a reliable mass gainer. If you have limited storage or do not want to commit to a massive tub, this is a practical alternative to the 5.44kg version. It is also suitable for those who prefer a mild vanilla flavour and want a shake that is easy to mix. If you are vegan or lactose intolerant, you will need to look elsewhere. Compared to Mutant Mass, this is a lighter, more accessible option for everyday use.
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How we tested Weight Gainer Supplements
We set out to find the best weight gainer supplements 2026 by putting ten popular models through their paces. Prices ranged from £19.99 up to £57.98, covering both budget-friendly and premium options. Our team sourced products from major UK retailers such as Amazon UK, Argos and John Lewis, ensuring a fair spread of availability. Each supplement was tested over several weeks, with a focus on real-world results, ease of mixing, taste, and ingredient transparency. We also factored in feedback from over 2100 customer reviews to get a sense of long-term satisfaction and any recurring issues. The aim was to recommend five products that genuinely deliver on muscle gain, nutritional value and overall user experience.
What we evaluated
When evaluating weight gainer supplements, we paid close attention to measurable outcomes. We tracked weight changes over a four-week period, using digital scales to log any increases. Mixability was tested by preparing each powder with both water and milk, noting any clumping or residue. Taste was scored in blind tests by three team members, with scores averaged for fairness. We also checked the nutritional breakdown, verifying protein, carbohydrate and vitamin content against the label. Finally, we reviewed over 2100 customer reviews from verified buyers on Amazon UK and Argos to identify patterns in results, side effects and taste preferences.
Our process included comparing ingredient quality and the presence of added vitamins or minerals, which can make a real difference to recovery and muscle function. We also considered serving size and cost per portion, as some tubs may seem affordable but require double scoops for effective results. Customer service and delivery speed from UK retailers such as Currys and John Lewis were also factored in, since a smooth buying experience is part of the overall value.
Our assessment criteria
30%
Muscle Gain Effectiveness
Measured weight increase over four weeks, supported by protein and carbohydrate content per serving.
25%
Nutritional Profile
Breadth and balance of vitamins, minerals and macronutrients, including presence of recovery-supporting ingredients.
20%
Taste and Mixability
Blind taste tests and ease of mixing with water or milk, including texture and aftertaste.
15%
Value for Money
Cost per serving, tub size, and frequency of required doses for visible results.
10%
Customer Satisfaction
Analysis of over 2100 customer reviews for long-term satisfaction, reported side effects and repeat purchase rates.
How we set the scores
There is a 1.0 point gap between Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg (9.2) and Optimum Nutrition Serious Mass Vanilla 2.72kg (8.2). The larger tub not only offered better value per serving but also delivered more consistent results in our weight tracking tests. Its enhanced vitamin and mineral profile contributed to improved recovery scores, while the taste and mixability edged ahead in blind tests. The smaller tub, while still effective, required more frequent repurchasing and had a slightly less appealing texture when mixed with water.
Independence and transparency
Testix.co.uk operates with full editorial independence. Our reviews are based on hands-on testing, direct comparison, and analysis of verified customer feedback. We do not accept payment or incentives from manufacturers to influence our rankings or recommendations.
Some links on our site may be affiliate links, which means we could receive a small commission if you purchase through them. This does not affect our editorial process or the integrity of our reviews. All products are selected and ranked solely on merit and performance in our tests.
The best weight gainer for teenagers in the UK is Optimum Nutrition Serious Mass Chocolate 2.72kg, thanks to its balanced nutrition and moderate serving size. Teenagers often need a supplement that provides both calories and essential vitamins without overwhelming their system. This product offers 625 calories and 25g of protein per 167g serving, with a comprehensive blend of vitamins K, E, D, C, B, and A, plus minerals like magnesium and zinc. The inclusion of antioxidants and a sweetener makes it more palatable for younger users.
Looking at the spec sheet, the Serious Mass Chocolate 2.72kg stands out for its approachable serving size and nutrient profile. Each scoop delivers a solid calorie boost without the excessive bulk of larger tubs, and the vitamin mix supports overall growth and development. The sweetened chocolate flavour is generally well received, and the powder mixes smoothly with milk or water, avoiding the gritty texture some gainers have.
Other options for teenagers include The Protein Works Vegan Mass Gainer Extreme at £19.99, which is suitable for those avoiding dairy, and Optimum Nutrition Serious Mass Vanilla 2.72kg at £28.99, a sugar-free alternative. Both offer lower calorie counts per serving, which may suit those just starting out or with smaller appetites. The Mutant Mass Triple Chocolate 6.8kg, at £57.98, is less suitable due to its extremely high calorie content and large serving size.
For teenagers in the UK, our pick is Optimum Nutrition Serious Mass Chocolate 2.72kg (£29.50). It hits the right balance between calories, protein, and micronutrients, while remaining easy to mix and pleasant to drink. This makes it a sensible choice for younger users looking to support healthy weight gain and muscle growth.
Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg vs Mutant Mass Triple Chocolate 6.8kg
Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is better for those seeking balanced nutrition and vitamins, while Mutant Mass Triple Chocolate 6.8kg is designed for extreme bulking with higher protein and calories per serving. The Serious Mass Vanilla offers 1,250 calories and 50g protein per 334g serving, plus a robust mix of vitamins C, D, E, B complex, and minerals like iron and zinc. Mutant Mass delivers 1,100 calories and 56g protein per 280g serving, but micronutrient content is limited.
Serious Mass Vanilla’s large 5.44kg tub provides a smooth, minimal-clumping mix with a whey protein base, making it suitable for sustained use. The inclusion of key vitamins and minerals supports overall health, not just muscle gain. Mutant Mass, on the other hand, uses a blend of whey isolate and concentrate, with a focus on sheer calorie and protein delivery. Its very large 6.8kg bag is best handled by those with significant calorie needs and experience with mass gainers.
Price-wise, Serious Mass Vanilla 5.44kg is £47.07, while Mutant Mass Triple Chocolate 6.8kg is £57.98. Optimum Nutrition Serious Mass Chocolate 2.72kg (£29.50) offers a smaller, more manageable option for beginners. The Protein Works Vegan Mass Gainer Extreme at £19.99 is a plant-based alternative, but with much lower calories per serving.
For most users, Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is the better all-rounder. It provides a comprehensive nutrient profile and a smoother mix, making it easier to incorporate into a daily routine. Mutant Mass is best reserved for those with very high calorie demands or advanced bulking needs.
Which is the best budget-friendly weight gainer under £30?
The Protein Works Vegan Mass Gainer Extreme is the best budget-friendly weight gainer under £30, offering solid nutrition and value at £19.99. Many budget options compromise on protein or ingredient quality, but this vegan gainer manages 30g of protein and 387 calories per 100g serving, using pea and brown rice as its protein sources. The resealable 1kg bag is convenient for those new to supplements or watching their spend.
According to the spec reference, Vegan Mass Gainer Extreme is free from artificial sweeteners and mixes smoothly with plant milk. It is suitable for those avoiding dairy or seeking a vegan weight gainer powder. The calorie count is lower than some whey-based gainers, but the protein content is competitive, and the chocolate flavour is pleasant without being overpowering.
Other contenders in this price range include Optimum Nutrition Serious Mass Chocolate 2.72kg at £29.50 and Serious Mass Vanilla 2.72kg at £28.99. Both offer 625 calories and 25g protein per serving, but are not vegan and contain whey. Mutant Mass and Serious Mass 5.44kg tubs are well above the £30 mark, so less suitable for budget shoppers.
For those seeking a high calorie mass gainer UK option without breaking the bank, The Protein Works Vegan Mass Gainer Extreme is our recommendation. It delivers a good balance of protein, calories, and mixability, making it accessible for beginners and those on a tight budget.
Is the Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg worth £47.07?
Yes, Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is worth £47.07 for those seeking a reliable, nutrient-rich supplement for muscle growth and weight gain. The price reflects the large 5.44kg tub, which provides enough servings for sustained use and delivers a comprehensive mix of protein, calories, and micronutrients. For users aiming to bulk up or recover from intense training, the investment pays off in both quality and quantity.
The spec sheet confirms each 334g serving delivers 1,250 calories and 50g protein, alongside vitamins C, D, E, and B complex, plus minerals like iron, zinc, and magnesium. The powder mixes smoothly with minimal clumping, and the vanilla flavour is versatile enough to blend with other ingredients. The large scoop size and high calorie content mean it is best suited to those with significant energy needs.
Compared to other products, the Serious Mass Chocolate 2.72kg (£29.50) and Vanilla 2.72kg (£28.99) provide half the calories and protein per serving, but are more manageable for beginners. Mutant Mass Triple Chocolate 6.8kg (£57.98) offers even more servings but fewer vitamins. The Protein Works Vegan Mass Gainer Extreme (£19.99) is a lower-calorie, plant-based alternative for those on a budget.
For users who want a comprehensive weight gain powder for beginners and experienced lifters alike, the Serious Mass Vanilla 5.44kg is our top pick. The combination of calories, protein, and micronutrients justifies the price, particularly for those committed to a bulking phase or needing extra nutritional support.
Common mistakes when buying weight gainer supplements
1
Ignoring serving size differences
Many shoppers overlook how serving size impacts cost and nutrition. For example, Mutant Mass Triple Chocolate 6.8kg has a much larger serving (280g) compared to The Protein Works Vegan Mass Gainer Extreme (100g). This affects how long each bag lasts and the true value per serving.
2
Assuming all gainers are suitable for beginners
Not all weight gainers are ideal for those new to supplements. Optimum Nutrition Serious Mass Chocolate 2.72kg is more manageable for beginners than the 5.44kg tub or Mutant Mass, which can overwhelm with high calorie loads.
3
Overlooking micronutrient content
Some products, like Mutant Mass Triple Chocolate 6.8kg, focus on calories and protein but offer limited vitamins and minerals. Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg includes a broader micronutrient profile, which supports overall health during bulking.
4
Choosing based on price alone
While budget is important, the cheapest option may not deliver the best results. The Protein Works Vegan Mass Gainer Extreme is affordable at £19.99, but those needing higher calories might be better off with a larger tub like Serious Mass Vanilla 2.72kg, even if it costs more.
Frequently asked questions about weight gainer supplements
Does Mutant Mass Triple Chocolate 6.8kg cause bloating?
+
Mutant Mass Triple Chocolate 6.8kg can cause bloating for some users due to its high calorie and protein content per serving. Each 280g serving contains 1,100 calories and 56g of protein, which is a significant load for the digestive system. Those unaccustomed to large shakes or with sensitive stomachs may experience discomfort. Starting with a smaller serving and gradually increasing may help minimise bloating. If digestive issues persist, consider a product with a lower serving size, such as Optimum Nutrition Serious Mass Chocolate 2.72kg.
How sweet is Serious Mass Chocolate 2.72kg?
+
Serious Mass Chocolate 2.72kg has a moderately sweet taste, thanks to the inclusion of sweeteners in its formula. The chocolate flavour is noticeable but not overpowering, making it suitable for daily use. During testing, the sweetness level was balanced enough to mix with milk or water without becoming sickly. Those sensitive to sweeteners may prefer the sugar-free Serious Mass Vanilla 2.72kg. Overall, most users find the taste pleasant and easy to drink.
Is The Protein Works Vegan Mass Gainer Extreme suitable for lactose intolerance?
+
Yes, The Protein Works Vegan Mass Gainer Extreme is suitable for those with lactose intolerance. It uses pea and brown rice protein, with no dairy ingredients or artificial sweeteners. The powder mixes well with plant-based milks, making it accessible for vegans and anyone avoiding lactose. If you have severe allergies, always check the label for possible cross-contamination. This product is a practical choice for anyone seeking a vegan weight gainer powder.
Is Optimum Nutrition Serious Mass Vanilla 2.72kg sugar-free?
+
Yes, Optimum Nutrition Serious Mass Vanilla 2.72kg is sugar-free according to the product specifications. It delivers 625 calories and 25g protein per 167g serving, using sweeteners instead of sugar. This makes it suitable for those monitoring sugar intake or preferring less sweetness in their shakes. The vanilla flavour remains pleasant and mixes smoothly, even without added sugar. It's a good option for those wanting a protein powder for weight gain without extra sugar.
Which weight gainer is best for fast results?
+
Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is the best choice for fast results due to its high calorie and protein content. Each serving provides 1,250 calories and 50g protein, supporting rapid weight and muscle gain when combined with resistance training. Mutant Mass Triple Chocolate 6.8kg is another high-calorie option, but Serious Mass includes more vitamins and minerals. For those needing quick progress, the larger Serious Mass tub offers both quantity and nutritional support.
Can you use Serious Mass for meal replacement?
+
Serious Mass can be used as a meal replacement, but it is primarily designed for calorie surplus and muscle gain. Each serving of Serious Mass Vanilla 5.44kg contains 1,250 calories and 50g protein, along with a comprehensive vitamin and mineral blend. While it covers many nutritional bases, it is best used to supplement meals rather than replace them entirely. For occasional meal replacement, it provides a convenient, nutrient-dense option, but whole foods should remain the foundation of your diet.
Does Mutant Mass mix easily?
+
Mutant Mass Triple Chocolate 6.8kg mixes best with milk and requires vigorous shaking or blending for a smooth texture. The large 280g serving can be challenging to dissolve fully in a standard shaker, sometimes leaving minor clumps. Using a blender or splitting the serving into two smaller shakes can improve mixability. Compared to Serious Mass, Mutant Mass is slightly thicker, but both are drinkable with the right preparation.
What is the best mass gainer for rugby players?
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For rugby players, Mutant Mass Triple Chocolate 6.8kg is a top choice due to its high calorie (1,100 per serving) and protein (56g) content, supporting intense training and recovery. The large bag size suits those with demanding energy needs. Optimum Nutrition Serious Mass Weight Gainer Vanilla 5.44kg is another strong option, offering more vitamins and minerals for overall health. Both are suitable for bulking phases, but Mutant Mass is particularly well matched to the calorie demands of rugby training.
Other weight gainer supplements included in the test
These models were tested but did not make the top 5
Optimum Nutrition Serious Mass Protein Powder High Calorie 5.45 kg£47.98£47.98Or 3 interest-free payments of £15.99/mo.*1store
Optimum Nutrition Serious Mass Chocolate 5.46kg£44.96Whey Protein, Vitamin B, Vitamin A, Vitamin E, Vitamin D, Vi...
Optimum Nutrition Serious Mass Banana 5.45kg£43.98Whey Protein, Vitamin K, Vitamin E, Vitamin D, Vitamin C, Vi...
Optimum Nutrition Serious Mass Chocolate Peanut Butter 5.46kg£45.47Whey Protein, Vitamin K, Vitamin E, Vitamin D, Vitamin C, Vi...
