Popular brand
Optimum Nutrition Gold Standard 100% Isolate Whey Protein powder · Chocolate Bliss · 44 Servings
$2.35 per 25 g protein
$103.49 a container
Priced per 25 g protein
Whey isolate price comparison
As of Nov 7, 2026, the cheapest whey isolate on our list is Transparent Labs Grass-Fed Whey Protein Isolate at $1.73 per 25 g protein, 26% less per 25 g protein than Optimum Nutrition.
- What is it?
- Milk protein filtered to about 90% protein, with very little fat or lactose.
- Why do people take it?
- An easy way to reach a daily protein goal, often after training. Many people who are sensitive to lactose tolerate it well.
- What does the research say?
- Strong evidence. Strong that enough daily protein, with resistance training, supports muscle gain. Whey is a high-quality source.
General information, not medical advice. Check with a doctor or pharmacist if you are pregnant, take medication or have a health condition.
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Cheapest whey isolate vs Optimum Nutrition
Top pick. Lowest price per serving among third-party tested products.
Transparent Labs Grass-Fed Whey Protein Isolate · 4LB · Unflavored
$1.73 per 25 g protein
26% less cost per serving than Optimum Nutrition
$109.99 a containerNSF Certified for Sport (opens in a new tab)
BuySave me money at Transparent Labs (opens in a new tab)Best for other needs
Best for stocking up
Muscle Feast Whey Protein Isolate, Pasture Raised, Grass Fed, rBST/rBGH and soy free · 5lb · Unflavored
$1.78 per 25 g protein, 24% less
75 servings of 25 g protein in one container, the most here.
BuySave me money at Muscle Feast (opens in a new tab)Lowest upfront cost
California Gold Nutrition Sport, Whey Protein Isolate, Unflavored · 1 lb
$1.95 per 25 g protein, 17% less
$30.80 for the container, the least to spend here.
BuySave me money at Vitacost (opens in a new tab)
Costs less than Optimum Nutrition
Top pick. Lowest price per serving among third-party tested products.
Transparent Labs Grass-Fed Whey Protein Isolate · 4LB · UnflavoredNSF Certified for Sport (opens in a new tab)Checked less than an hour ago
$1.73 per 25 g protein26% less than Optimum Nutrition per 25 g protein
BuySave me money at Transparent Labs (opens in a new tab)- Muscle Feast Whey Protein Isolate, Pasture Raised, Grass Fed, rBST/rBGH and soy free · 5lb · Unflavored
Checked less than an hour ago
$1.78 per 25 g protein24% less than Optimum Nutrition per 25 g protein
BuySave me money at Muscle Feast (opens in a new tab) - Jacked Factory Authentic Iso, Whey Protein Isolate · 25 Servings · Vanilla Oatmeal Cookie
Checked less than an hour ago
$1.80 per 25 g protein23% less than Optimum Nutrition per 25 g protein
BuySave me money at Jacked Factory (opens in a new tab) - ProMix Unflavored Whey Isolate Protein Powder · 1 Bag
Checked less than an hour ago
$1.86 per 25 g protein21% less than Optimum Nutrition per 25 g protein
BuySave me money at ProMix (opens in a new tab) - California Gold Nutrition Sport, Whey Protein Isolate, Unflavored · 1 lb
Checked less than an hour ago
$1.95 per 25 g protein17% less than Optimum Nutrition per 25 g protein
BuySave me money at Vitacost (opens in a new tab) - NutraBio Whey Protein Isolate Powder · 50 Servings · Unflavored
Checked less than an hour ago
$2.20 per 25 g protein6% less than Optimum Nutrition per 25 g protein
BuySave me money at NutraBio (opens in a new tab)
Also on this list
- Dymatize ISO100 Hydrolyzed, 100% Whey Protein Isolate, Gourmet Chocolate · 1.43 lb
Checked less than an hour ago
$2.81 per 25 g protein
BuySave me money at Vitacost (opens in a new tab) - Raw Nutrition Essentials, Grass Fed Whey Isolate Protein, Dark Chocolate · 2 lb
Checked less than an hour ago
$2.98 per 25 g protein
BuySave me money at Vitacost (opens in a new tab) - Momentous Whey Protein Isolate · Unflavored
NSF Certified for Sport (opens in a new tab)Checked less than an hour ago
$3.50 per 25 g protein
BuySave me money at Momentous (opens in a new tab)
A row goes up only when the store page states the protein per scoop and the scoop weight. The price is divided across the protein in the tub, not the powder. Affiliate links, when we have them, don't change the price.
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Cheaper alternatives
- Cheaper alternatives to Optimum Nutrition whey isolate6 products cost less per 25 g protein than Optimum Nutrition, up to 26% less.
- Cheaper alternatives to Dymatize whey isolate7 products cost less per 25 g protein than Dymatize, up to 38% less.
Brand vs brand
- Optimum Nutrition vs Transparent Labs whey isolateTransparent Labs costs 26% less per 25 g protein than Optimum Nutrition: $1.73 vs $2.35.
- Dymatize vs Transparent Labs whey isolateTransparent Labs costs 38% less per 25 g protein than Dymatize: $1.73 vs $2.81.
Whey isolate buying guides
- Best whey protein isolate 2026: cost per 25 g proteinThe best-value whey isolates right now, ranked by what you pay for 25 g of protein rather than per scoop or per tub, plus how to spot a blend sold as isolate.
- Whey isolate vs concentrate: is isolate worth it? Price per 25 g proteinIsolate is at least 90% protein with very little lactose; concentrate is cheaper and fine for many people. Compare tubs by cost per 25 g of protein.
Whey isolate prices: questions
- What is the cheapest whey isolate right now?
- As of Nov 7, 2026, the cheapest whey isolate on our list is Transparent Labs Grass-Fed Whey Protein Isolate at $1.73 per 25 g protein, 26% less per 25 g protein than Optimum Nutrition. Prices on the list run from $1.73 to $3.50 per 25 g protein.
- What is the cheapest third-party tested whey isolate?
- As of Nov 7, 2026, it is Transparent Labs Grass-Fed Whey Protein Isolate at $1.73 per 25 g protein. Tested means the product is listed in a testing program's own database (NSF, USP, Informed Sport, Informed Choice or IFOS), checked by a person, not taken from the brand's word.
- How much does whey isolate cost per 25 g protein?
- The median price on our list is $1.95 per 25 g protein, across 10 prices from 8 stores. Optimum Nutrition, a brand people already buy, costs $2.35 per 25 g protein.
- How do you compare whey isolate prices?
- Prices shown per 25 g of protein, not scoop weight. Powder only. Blends and concentrates stay off this list. We divide each store price by the amount in the container, so a big tub and a small bottle compare fairly.
- How often are prices checked?
- Once a day, from each store's own page. The last check was Nov 7, 10:01 AM ET. We don't sell the products, and affiliate links never change the order.
Every whey isolate product we price (10)
- Transparent Labs Grass-Fed Whey Protein Isolate · 4LB · Unflavored$1.73 per 25 g protein
- Muscle Feast Whey Protein Isolate, Pasture Raised, Grass Fed, rBST/rBGH and soy free · 5lb · Unflavored$1.78 per 25 g protein
- Jacked Factory Authentic Iso, Whey Protein Isolate · 25 Servings · Vanilla Oatmeal Cookie$1.80 per 25 g protein
- ProMix Unflavored Whey Isolate Protein Powder · 1 Bag$1.86 per 25 g protein
- California Gold Nutrition Sport, Whey Protein Isolate, Unflavored · 1 lb$1.95 per 25 g protein
- NutraBio Whey Protein Isolate Powder · 50 Servings · Unflavored$2.20 per 25 g protein
- Optimum Nutrition Gold Standard 100% Isolate Whey Protein powder · Chocolate Bliss · 44 Servings$2.35 per 25 g protein
- Dymatize ISO100 Hydrolyzed, 100% Whey Protein Isolate, Gourmet Chocolate · 1.43 lb$2.81 per 25 g protein
- Raw Nutrition Essentials, Grass Fed Whey Isolate Protein, Dark Chocolate · 2 lb$2.98 per 25 g protein
- Momentous Whey Protein Isolate · Unflavored$3.50 per 25 g protein