Cheapest Mass Gainer UK Ingredients: What the Evidence Says

A mass gainer is a high calorie protein powder built for people who struggle to eat enough food to gain weight. You will also see them called weight gainers or bulking powders.

The target audience is hardgainers, meaning people with fast metabolisms or small appetites who find it physically hard to eat enough calories from food alone. If you are already hitting your calorie target through regular meals, you almost certainly do not need one.

Mass gainers are meant to sit alongside a proper diet, filling the gap between what you can eat and what you need to eat. If food alone can close that gap, save your money.

Here is the honest truth: most mass gainers are mostly maltodextrin. That is a cheap, highly processed carbohydrate derived from corn or wheat starch. It has a high glycemic index, no nutritional value beyond calories, and costs manufacturers very little to produce.

A typical mass gainer ingredient breakdown looks like this.

1. 1

   60 to 70% maltodextrin or a similar carb filler.

2. 2

   20 to 30% whey protein or a protein blend.

3. 3

   Flavouring, sweeteners, and thickeners.

4. 4

   Sometimes added creatine, glutamine, or vitamins.

Some premium options swap maltodextrin for oat flour, sweet potato powder, or MCT oil. These are better nutritional choices, but they cost more.

Protein quality also varies hugely between brands. Some use 100% whey protein concentrate or isolate. Others pad the blend with cheap soy or wheat protein just to hit a number on the label without spending on quality ingredients.

For live, updated prices across every mass gainer we track, check the mass gainer comparison table. Prices change weekly, so always check before buying.

Not all mass gainers are created equal. Here is what to look for on the label if you want a genuinely useful product.

Rank	Product	Best for	ProteinDeals verdict
1	Whey protein concentrate or isolateFrom £49.95 Pros +Whey concentrate supplies a complete essential-amino-acid profile +24g protein per 100g Cons −26.1% above the £1.24/100g average across 18 comparable /compare listings −Whey concentrate may not suit lactose-sensitive users	Best overall	listed as the first protein source.
2	Oat flour or ground oats	Best-value alternative	as the main carbohydrate.
3	Low sugar content	Specialist option	, under 10g per 100g.

These are the signals that a product is leaning on filler rather than quality.

1. 1

   Maltodextrin listed first among the ingredients.

2. 2

   A protein blend that includes soy or wheat protein.

3. 3

   More than 10 ingredients on the label.

4. 4

   Sugar content above 15g per 100g.

MyProtein Impact Weight Gainer and Applied Nutrition Critical Mass use cleaner formulas than most. MyProtein leans on oat flour as its primary carb source, which gives slower energy release and more fibre than maltodextrin. Applied Nutrition includes added creatine, a genuinely useful extra.

Always compare products by protein per 100g rather than per serving. Serving sizes can run to 200g or even 300g or more, which makes per serving comparisons misleading. A product claiming "50g protein per serving" sounds impressive until you notice the serving itself is 334g.

The cheapest mass gainer of all is the one you make yourself. A DIY mass gainer shake is simple to put together.

1. 1

   1 scoop whey protein (25g protein).

2. 2

   80g oats, blended into a powder.

3. 3

   1 tablespoon peanut butter.

4. 4

   1 banana.

5. 5

   300ml whole milk.

That combination gives you roughly 700 calories and 45g of protein. The cost works out to around £1 to £1.50 per shake using supermarket ingredients and a decent whey concentrate.

A commercial mass gainer typically costs £2 to £4 per shake, depending on the brand and bag size, so a DIY shake saves roughly 50 to 70% per serving.

The trade off is convenience. Commercial mass gainers are faster to prepare, since it is scoop, shake, done, while a DIY shake needs a blender and a few minutes of prep. If you are rushing between lectures or shifts, that matters more than the saving.

For a deeper dive into the cost breakdown, read our affordable mass gainer UK guide.

This is the question most people should ask before buying a mass gainer at all. In most cases, whey protein is the better buy.

Whey protein gives you more protein per pound spent. A typical whey concentrate delivers 70 to 80g of protein per 100g, while a typical mass gainer delivers only 20 to 30g. Per gram of protein, whey is dramatically cheaper.

If you can eat enough food to hit your calorie target, buy whey protein and eat more food instead. It is cheaper, cleaner, and gives you more flexibility with your diet.

Mass gainers really only make sense in one scenario: your appetite is genuinely too low to eat enough solid food. If you are already eating three meals a day and still not gaining weight, a mass gainer shake between meals can help bridge that gap.

For most people though, a bag of whey concentrate with your own added carbs is the smarter move.

Most mass gainers are overpriced maltodextrin. That is the blunt reality, and you are paying a premium for convenience and marketing rather than quality nutrition.

A few options do stand out. MyProtein Impact Weight Gainer uses oat based carbs and delivers 29g protein per 100g. Applied Nutrition Critical Mass offers 28g protein per 100g with added creatine. These are the ones worth considering if you genuinely need a commercial mass gainer.

For the latest prices on every mass gainer we track, check the mass gainer comparison table. It updates weekly and sorts by best value per serving.