Signature Mass Gainer Review

A picture of Best Mass Gainer UK founder, personal trainer Andy Williams
Written By
Andy Williams
Last Updated on

In our Signature Mass Gainer review, I’ll delve into the pros and cons of this 810-calorie strong weight gainer to see if it’s worth your money.

The team over at have decades of supplement industry experience, so I have high hopes for their long-awaited mass gainer. Let’s see if it lives up to my expectations.

ideal for weight gain Signature Mass Gainer
A tub of Signature Mass Gainer next to a shaker bottle and scooper
Taste: 8.8/10
Mixability: 9.1/10
Ingredient Quality: 9.6/10
Mass-Building Potential: 9.5/10
Overall Rating: 9.3/10
  • Includes 810 growth-stimulating calories
  • Fuels hard bulking workouts with 133g of complex carbs
  • Sparks new muscle growth with 50g of premium protein
  • Varied protein sources provide a sustained release of amino acids
  • Created by pioneers in the bodybuilding supplement industry
  • Mixes easily in any standard shaker bottle
  • Get the lowest price in April
  • Some people might do better with a lower-calorie gainer
  • Only two flavours are available currently Signature Mass Gainer Nutrition Facts

The Signature Mass Gainer nutrition facts

I like that this mass gainer has a simple yet effective formula. Unlike other brands, doesn’t waste our time bragging about how much glutamine or—even worse—unnecessary creatine they managed to shove into their mass gainer.

As you can see from the list of ingredients, this formula is designed for putting on quality size.

  • Calories: 810
  • Carbohydrates: 133g
  • Protein: 50g
  • Fats: 9g
  • Sugar: 8g
  • Fibre: 5g
  • Probiotics: Boosts protein absorption (important when bulking).

This mass gainer is designed for those who want to bulk up and need the extra calories to support their intense training sessions. With its high calorie, protein, and carbohydrate formula, it provides the fuel you need to build muscle and put on some serious size. Signature Mass Gainer Ingredients

Protein—Whey, Casein, Egg Whites

The Signature Mass Gainer ingredients Signature Mass Gainer contains high-quality proteins from three different sources: whey, casein, and egg whites. 

With 50 grams of muscle-building protein per serving, this blend offers a well-rounded amino acid profile for optimal muscle growth. 

Whey protein is quickly absorbed and provides a rapid increase in amino acids, while casein and egg whites deliver a slower release to support prolonged muscle protein synthesis.

ModCarb—Oat Bran, Quinoa, Buckwheat Millet

To support growth-stimulating bulking workouts and replenish your glycogen stores, this mass gainer includes a unique complex carbohydrate blend known as ModCarb. This blend consists of whole-grain carb sources such as oat bran, quinoa, and buckwheat millet, which provide you with sustained energy and training fuel. 

Cluster Dextrin and Maltodextrin

The macros for the mass gainer

Maltodextrin is a rapidly absorbed carbohydrate that fuels fast-twitch muscle fibres during intense workouts. It also helps to replenish muscle glycogen after training, helping your muscles to look pumped and full rather than flat and depleted.

Conversely, cluster dextrin is a slower-digesting carb that provides you with sustained energy over longer periods of time—perfect for those long and hard bulking workouts. 


To optimise the absorption and utilisation of the nutrients found in Bodybuilding Signature Mass Gainer, probiotics are included in the formula. These beneficial bacteria help to improve gut health and overall digestion, ensuring that your body gets the most out of the high-quality protein, carbohydrates, and other nutrients provided by this supplement.

ideal for bulking
A tub of Signature Mass Gainer Signature Mass Gainer
CLICK FOR BEST PRICE Signature Mass Gainer Taste

The Signature Mass Gainer in chocolate flavour

I've checked out numerous Signature Mass Gainer reviews, and it’s clear that most users enjoyed the taste—as did I, and I’m very picky.

Customers often praised the taste of both the chocolate and vanilla flavours and have compared it positively with other mass gainers on the market. They appreciate the fact that it's not overly sweet, and many find it enjoyable to mix with their favourite beverages, such as milk or water.

Personally, my shakes were always lump-free (which is more than you can say for most mass gainers), and they had the perfect amount of sweetness. It seems like decades of supplement industry experience has paid off for

Obviously, as with any mass gainer, not everyone is going to rave about the taste. Unlike nutrition and ingredients, which are more objective, taste and flavours are more a matter of personal preference.

Bodybuilding.Com Mass Gainer Mixability

A man putting powder in a shaker bottle for his Signature Mass Gainer review

Mixability is important when it comes to any kind of nutritional shake—especially high-calorie mass gainers. 

After all, you want a consistent and smooth shake that's easy to drink and doesn't leave any lumps or residue sticking to your shaker (aka lost calories). 

With's Signature Mass Gainer, I’m pleased to say that mixability is a breeze.

Firstly, I noticed that the powder dissolves easily in water or milk, making it a versatile choice for those who prefer different liquid bases for their shakes. There's no need to worry about stubborn clumps or residue ruining the texture of your drink. Just give it a good shake, and you're all set!

Another aspect of the Signature Mass Gainer's mixability is its compatibility with other ingredients. If you're the slightly adventurous type (like me) who enjoys customising your shake with various fruits, nuts, or even other protein powders, this mass gainer complements them well. The result is a delicious and nutritious concoction tailored precisely to your liking (both macro and ingredient-wise).

Are There Any Side Effects?

I’ve noticed that when it comes to weight gainers like's Signature Mass Gainer, people often have concerns about potential side effects. So, I thought it'd be helpful to address these concerns and discuss some of the possible issues that could arise from using mass gainers.

The Signature Mass Gainer scoop size

First off, one of the most common issues people face with mass gainers is unhealthy weight gain. While the primary goal of these products is obviously to help you gain weight, it's crucial to remember that not all weight gain is necessarily good. Past a certain point, any extra calories you consume will likely be diverted to fat storage rather than muscle growth.

Of course, some fat gain is part and parcel of an effective bulking phase. But you don’t want to be downing a mass gainer with each meal or anything like that. Depending on your calorie requirements, I recommend having 1-2 shakes per day.

I should also mention that some people have reported stomach problems after using mass gainers in general. This could be due to the high amounts of protein and carbohydrates in the product, which may cause digestive discomfort, bloating, or even diarrhoea in some cases. 

Thankfully, this should be much less of an issue with the Bodybuilding Signature Mass Gainer because of the probiotics.

Other Popular Mass Gainers:

810 calories
A tub of Signature Mass Gainer Signature Mass Gainer

Who Should Buy Signature Mass Gainer? Signature Mass Gainer is an excellent supplement for those looking to add serious size to their frame or anyone who considers themselves a hardgainer.

A tub of Signature Mass Gainer next to a shaker bottle and scooper

To put it simply, this mass gainer is nothing less than fantastic for individuals who have a tough time putting on weight and muscle. Each serving is loaded with 810 calories, 50 grams of muscle-building protein, and 133 grams of workout-fueling carbohydrates, making it just the right choice for a clean bulk.

So, if you're someone who spends hours at the gym, working tirelessly to get those gains but still has a hard time achieving your goals, Signature Mass Gainer could be the perfect solution for you.

Now, if you’re just maintaining your weight, then I’d steer clear of mass gainers like this because they will make you heavier. We all have different gym goals at the end of the day.

Who Should Avoid Signature Mass Gainer?

The protein featured in Signature Mass Gainer

As much as I appreciate the benefits of this high-calorie supplement, I wanted to keep this Signature Mass Gainer review completely honest.

First and foremost, if you're someone looking to gain only a very modest amount of weight, this product might not be the best fit for you. While it can help pack on the pounds, it's designed for people who struggle to gain weight and need a more significant boost in their caloric intake. 

In other words, it's created for hardgainers. If you're not in this category and only wish to gain a small amount of weight, you may want to explore other options with lower calories or just adjust your regular diet.

Should You Add This Weight Gainer To Your Supplement Stack?

Since's mass gainer contains a balanced blend of proteins, carbohydrates, and healthy fats, it contributes to your daily caloric intake, thus supporting weight gain.

Unlike lower-quality gainers that are often full of soy protein, the Signature Weight Gainer only includes premium protein sources, namely whey, casein, milk protein, and egg whites.

As for convenience, weight gainers like the one from save us time and effort. Preparing and consuming numerous meals throughout the day can be tiresome and time-consuming. This weight gainer presents an easier way to get a large chunk of our daily macro needs in one go.

However, on the flip side, it's important to acknowledge that weight gainers aren't for everyone. If you're someone with a small appetite or a fast metabolism, this product might come in handy. 

However, if you're already getting sufficient calories from whole food sources, adding a mass gainer might lead to an unnecessary calorie surplus, causing unwanted fat gain.

In summary, the Signature Mass Gainer is a valuable addition to your stack if you need extra calories to facilitate muscle growth and boost your gym performance. 

ideal for mass gain
A tub of Signature Mass Gainer Signature Mass Gainer
A picture of Best Mass Gainer UK founder, personal trainer Andy Williams
Andy Williams
Andy Williams is a UK-based personal trainer and bodybuilder who coaches gym-goers of all levels using proven evidence-based techniques in strength training, nutrition, and supplementation. He’s tested over 70 different mass gainers for their ingredient quality and muscle-building effectiveness and regularly shares his findings in his mass gainer reviews.
the logo for Best Mass Gainer UK showing a tub of weight gainer protein powder
We test and review every mass gainer and weight gainer on the UK market so that British fitness enthusiasts can make informed supplementation decisions.
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