Is Amazon or Walmart cheaper for protein powder?

Q: How We Compare (Methodology)?

We pulled the median Amazon price (including Subscribe & Save where the SKU offers it) and median Walmart price (including online + same-day pickup, excluding promo-card stacking) for every brand-and-size pair both retailers carry. That gave us 184 head-to-head SKUs. We then computed cost per kg of protein for each, because absolute tub price hides the truth when sizes differ. Both retailers move prices weekly. Snapshot pricing is misleading; the trend over the last 90 days is what matters and is what we used. 1. Mid-to-premium tubs over $40. Brands like Optimum Nutrition , Dymatize , Transparent Labs , and Legion consistently land 5-12% cheaper on Amazon once Subscribe & Save is applied. The first-subscription 20% coupon (when you stack 5+ items) pushes the gap to 15-20% for the first order.

Q: Costco vs Sam's Club Protein: Which Warehouse Wins?

Costco wins on Premier Protein RTDs and Kirkland whey; Sam's Club wins on Member's Mark bars and Quest multipacks. Real 2026 per-gram math i

Question

Is Amazon or Walmart cheaper for protein powder?

ProteinPrice Editorial · Accepted Answer

Across the 64 brands we track in 2026, Amazon wins on roughly 60% of the comparable SKUs once you stack Subscribe & Save (5-15% off) and the periodic 20% off first-subscription coupon. Walmart wins on its own house brands (Body Fortress, Pure Protein bars), some Premier Protein multipacks, and any time you can use same-day pickup to avoid shipping. The split is brand-specific, not blanket.

Amazon vs Walmart Protein Powder: Where Do You Save More?