Serious Gainz
by The Bulk Protein Company
Calories that count: a high-protein, high-carb formula built for serious muscle and weight gain.
- Up to 27g protein per serving
- High calorie for bulking phases
- For shakes, smoothies, baking and more
FlavourForest Gateau
Size5kg
Best price today
In stock£39.62
£0.79 / 100g
You save £0.37vs highest tracked price today
Secure retailer checkout
We may earn a commission at no extra cost to you. Affiliate disclosure
Transparent protein profile
What's inside
Values per 100g, with the amount in one 125g serving
22g protein
27g per 125g serving
59g carbohydrates
74g per 125g serving
5g fat
6.3g per 125g serving - moderate fat
368 kcal
460 kcal per 125g serving
View full nutritional information
| Nutrient | Per 100g | Per serving (125g) |
|---|---|---|
| Protein | 21.6g | 27g |
| Calories | 368 kcal | 460 kcal |
| Carbohydrates | 59.2g | 74g |
| Fat | 5g | 6.3g |
Know when to buy
Price history
Lowest price on record, any flavour or size
£0.63/100g (£31.59 for 5kg on 8 Oct 2026)
5kg · all flavours · price per pack
- Amazon UKlatest £39.62, lowest £31.59, highest £39.99 in the last 90 days
Quick answers
Is this right for you?
Who is it for?
The Bulk Protein Company Serious Gainz is designed for hard-gainers and anyone in a dedicated bulking phase who struggles to eat enough calories. Mass gainers combine protein with carbs and calories to support weight gain and muscle growth during intense training blocks.
What can you expect?
A calorie-dense shake designed to help you gain weight. Mass gainers pack protein alongside a significant amount of carbohydrates and calories per serving. Servings tend to be larger than standard protein powders, so expect thicker shakes and bigger scoops. With 21.6g of protein per 100g (around 27g per 125g serving), The Bulk Protein Company Serious Gainz sits in a competitive position for a mass gainer product.
What else do you need to know?
The Bulk Protein Company Serious Gainz is a mass gainer protein powder made by The Bulk Protein Company. It comes in 5kg sizes. Every price on WheyWise is read from the retailer’s own page and re-checked daily and sorted by cost per 100g, so you can see both the cheapest option and how current it is. All links to Amazon and retailer sites are affiliate links - this is how WheyWise stays free.
Frequently asked questions
Where is the cheapest place to buy The Bulk Protein Company Serious Gainz in the UK?
The best price we have verified today is £0.79 per 100g for the 5kg bag, checked 26 Oct 2026. Use the buy button above to go straight to it.
How much protein does Serious Gainz contain per 100g?
Serious Gainz contains 21.6g of protein per 100g, with 27g per 125g serving. It is a mass gainer product.
Is The Bulk Protein Company Serious Gainz currently in stock?
At the last check, 3 out of 3 tracked variants were in stock. Stock status carries the same fetch time as the price shown above, so check the retailer listing before ordering.
Pick your pack
1 size · any flavour · cost per 100g for each
Where to buy in the UK
5kg · 3 offers for this selection · sorted by cost per 100g
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