As dieters slim down, protein prices bulk up. Whey protein—a cheesemaking byproduct—has found new life among weight-loss drug users, athletes, and others seeking protein on slimmed-down diets. Companies from Dunkin’ Donuts to Marks and Spencer have rushed to 'proteinmaxx' their products; Starbucks includes whey in many drinks.

Inventories are low—USDA stocks at June were half the levels of three years prior—and prices sky-high. In the US, prices for 80% whey protein concentrate more than doubled in the first six months of 2026. This has caused buyers of whey to squeal as profitability narrows.

Higher prices lopped 1.2 percentage points off ebitda margins at THG’s nutrition division last fiscal year. But those negotiating prices for the fourth quarter may take solace—the balance of power has tipped fractionally in buyers’ direction. Demand is still buoyant; the rash of new products appearing on supermarket shelves attests to that.

However, high prices are doing what high prices in commodity markets invariably do. Manufacturers have invested in expanding production, though this is easier in the US than in the EU, where prices are also rising but regulation makes it harder to scale up. That helps explain why EU prices are higher, and the transatlantic gap is widening.

Meanwhile, food producers are exploring alternatives. It’s tricky to reproduce the taste of dairy protein, but in some cases egg or even plant proteins will do; some of the latter are running at about one-tenth the cost of whey. In some cases, bulking up can help: [PERSON_NAME]’s protein and collagen blends, for example.

It’s unlikely that demand will budge much, though. The take-up of GLP-1s for weight loss—which have the effect of suppressing appetites and depleting muscle—continues to rise, adding to the clamor for whey protein. About 7% of the US population uses, or has used, weight-loss drugs; the proportion is twice that in the EU already, and changes to availability under state-backed health insurance could swell that further.

Bulking season is just getting started.