Cheapest whey protein isolate (WPI)
Isolates have the most protein per scoop, so the cheapest WPI is often cheaper per gram of protein than many concentrates. Prices updated 7 Nov 2026
Australia: Bulk Nutrients Whey Protein Isolate at Bulk Nutrients: A$95 per kg of protein (A$79.00 for 1 kg, 83% protein).
United Kingdom: EFECTIV Nutrition Grass Fed Whey Protein Isolate - 66 Servings - EFECTIV® at EFECTIV Nutrition: £36 per kg of protein (£64.99 for 2 kg, 90% protein).
| # | Product | A$ per kg of protein | Price | Protein | Link |
|---|---|---|---|---|---|
| 1 | Bulk NutrientsWhey Protein Isolate | A$95A$2.86 per 30 g protein | A$79.001 kg | 83%label | View Bulk Nutrients Whey Protein Isolate at Bulk Nutrients |
| 2 | Bulk NutrientsHASTA Whey Protein Isolate | A$96A$2.89 per 30 g protein | A$82.001 kg | 85%label | View Bulk Nutrients HASTA Whey Protein Isolate at Bulk Nutrients |
| 3 | Bulk NutrientsNatural Whey Protein Isolate | A$99A$2.96 per 30 g protein | A$80.001 kg | 81%label | View Bulk Nutrients Natural Whey Protein Isolate at Bulk Nutrients |
| 4 | Bare BlendsBare Whey Protein Isolate | A$146A$4.38 per 30 g protein | A$94.99750 g | 87%label | View Bare Blends Bare Whey Protein Isolate at Bare Blends |
| 5 | Pillar PerformanceGrass Fed WPI | A$169A$5.06 per 30 g protein | A$134.951 kg | 80%label | View Pillar Performance Grass Fed WPI at Nutrition Warehouse |
| 6 | MusashiWhey Protein Isolate - WPI | A$190A$5.69 per 30 g protein | A$133.49900 g | 78%label | View Musashi Whey Protein Isolate - WPI at Musashi |
Prices checked 7 Nov 2026 (daily), cheapest flavour and best-value size in stock, before shipping and discount codes. Protein % is from each label. How we calculate.
No United States products match this list yet. We add merchants every week.
| # | Product | £ per kg of protein | Price | Protein | Link |
|---|---|---|---|---|---|
| 1 | EFECTIV NutritionGrass Fed Whey Protein Isolate - 66 Servings - EFECTIV® | £36£1.08 per 30 g protein | £64.992 kg | 90%label | View EFECTIV Nutrition Grass Fed Whey Protein Isolate - 66 Servings - EFECTIV® at EFECTIV Nutrition |
| 2 | EFECTIV NutritionEFECTIV® Clear Whey Protein Isolate | £62£1.87 per 30 g protein | £29.99600 g | 80%label | View EFECTIV Nutrition EFECTIV® Clear Whey Protein Isolate at EFECTIV Nutrition |
| 3 | Supplement NeedsVegan Iso+ - 1kg | £66£1.99 per 30 g protein | £39.991 kg | 60%label | View Supplement Needs Vegan Iso+ - 1kg at Supplement Needs |
Prices checked 7 Nov 2026 (daily), cheapest flavour and best-value size in stock, before shipping and discount codes. Protein % is from each label. How we calculate.
Reading a WPI label
Look for the per 100 g column on the nutrition panel. A good isolate is usually 80% protein or more. Flavoured isolates are a few points lower than unflavoured ones because flavour, cocoa and sweetener take up weight. When a product shows different panels for each flavour, we use the lowest one so we never overstate the protein.
Is WPI worth it over concentrate?
It depends on what you pay per kg of protein. Isolate often costs 20–40% more per kg of powder, but because it carries 10–15 more grams of protein per 100 g, the gap per kg of protein can be small. Our isolate vs concentrate guide compares the medians in each country.
FAQ
What makes a whey isolate?
Whey protein isolate (WPI) is whey filtered further than concentrate to remove more fat and lactose. Labels usually show roughly 80–92% protein. Clear whey is a hydrolysed or acidified isolate mixed like a juice.
Is whey isolate lactose-free?
Usually not fully. Most isolates are low in lactose but still contain a little. If you need lactose-free, check the label or look at plant, beef or egg protein. See our lactose-free guide.
Is clear whey better value?
Rarely on price. Clear whey is usually among the dearest per kg of protein in our tables. You pay for the format, not more protein.
Related guides
- Cheapest whey protein
Every whey (isolate, concentrate, blends) ranked by price per kg of protein.
- Whey isolate vs concentrate: is WPI worth the extra?
Label protein %, price per kg of protein, and who each suits.
- Best value protein powder
Value = price per gram of protein. The full ranking, updated daily.
- Protein cost per gram calculator
Work out price per kg of protein for any tub in 10 seconds.
- Cheapest vegan & plant protein powder
Pea, rice, soy and blends ranked by price per kg of protein.
- Cheapest casein protein
Micellar casein ranked by price per kg of protein.
General information only, not medical or dietary advice. Check the label for allergens and talk to a doctor or dietitian if you are pregnant, have a medical condition or take medication.