Quick Picks
Eight products that made our shortlist after filtering across all 12 tracked US retailers. Click any pick to see live prices, all retailers, and the latest deal.
How We Ranked These
We filtered to products explicitly marketed as zero-carb or pure isolates with a 0g carb claim on at least one flavor. Isopure dominates this category, but a few RTD shakes and pure isolates also qualify.
All prices verified within the last 24 hours. We re-check every product across all 12 tracked retailers (Walmart, Amazon, iHerb, GNC, Bodybuilding.com, Target, Vitacost, Muscle & Strength, Costco, Tiger Fitness, MyProtein, Transparent Labs) every two hours. Out-of-stock products are excluded from these rankings entirely.
Our Top Pick
7.5 lb · 25g protein/scoop · 103 servings
The zero-carb category is essentially Isopure's playground. 25g protein, 0g carbs, 0g fat. Pure protein, nothing else. Available in chocolate, vanilla, alpine punch, and the giant 7.5 lb format for best value. See Costco price →
Runner-Up
3 lb · 25g protein/scoop · 41 servings
Isopure in a smaller 3 lb format. Same zero-carb formula, lower upfront cost. See iHerb price →
Honorable Mentions
The next picks worth knowing about. Slightly different trade-offs but still in the top tier for this category.
Isopure Zero Carb Protein Drink (12-Pack). 20g protein/scoop, $26.99 at Amazon.
Isopure Zero Carb Protein Drink (12-Pack). 20g protein/scoop, $26.99 at Amazon.
Nutricost Whey Protein Isolate. 5 lb, 25g protein/scoop, $41.99 at Amazon.
Transparent Labs 100% Whey Protein Isolate. 5 lb, 28g protein/scoop, $59.99 at Transparent Labs.
See live Isopure pricing across retailers
Isopure dominates the zero-carb category. See live pricing on every Isopure flavor and size.
See Isopure pricing →Frequently Asked Questions
Isopure Zero Carb Whey Isolate. 25g protein, 0g carbs, 0g fat per scoop. It's the only mainstream protein powder we track that hits a true 0g carb mark consistently across flavors. Available in 3 lb tubs and a 7.5 lb format that delivers the best per-gram cost.
No. Zero-carb is useful for anyone tracking macros tightly: cutting bodybuilders, anyone on a sub-50g-carb day, or athletes who hit their carbs from whole-food sources and want their protein shake to not contribute. It's a flexible tool, not a keto-only product.
Slightly faster. With no carbs to slow gastric emptying, pure protein hits your bloodstream a touch faster. The difference is small (5 to 10 minutes) but can matter for fast-twitch post-workout protein delivery.
Whey naturally contains lactose (a milk sugar / carb). Concentrate has ~5 percent lactose, isolate ~1 percent, and only ultra-filtered or ion-exchanged isolate hits 0 percent. The processing required to hit true zero adds 20 to 30 percent to the manufacturing cost.
Both. Their main lineup is flavored (Dutch Chocolate, Creamy Vanilla, Alpine Punch) and uses sucralose for sweetness. The Unflavored version exists and works well in cooking or as a clean base for your own flavoring.
Not necessarily. Isopure uses sucralose, which has zero calories and zero carbs (FDA allows zero rounding under 0.5g). If you want a stevia-sweetened zero-carb option, your choices narrow significantly.
Related Rankings
Other useful price comparisons on ProteinPrice.com:
- The full best-value protein ranking across all 377 tracked products.
- Head-to-head product comparisons across our catalog.
- Browse whey isolate, the cleanest whey category by macros.
- Browse all whey protein blends, isolates, and concentrates.
- Casein protein for slow-release recovery and bedtime use.
- Plant protein from pea, rice, hemp, and soy blends.
- Mass gainers for hard gainers and calorie-surplus bulking.
- Protein bar comparisons across 70+ tracked bars.
- Ready-to-drink shakes and protein waters.
- Current protein deals live across all retailers.