Protein supplements, commonly used by fitness enthusiasts and those looking to build muscle or support weight loss, have seen a dramatic price increase in recent years. Consumers are reporting that the cost of a 4.5kg bag of whey protein, a popular type of supplement, has risen by as much as £100, with some now paying £170 for the same product. Amarpreet Singh, a 30-year-old London-based banker, recalls paying £60 for the same bag in 2020, which had climbed to £120 by last year. To manage the cost, he now buys a cheaper brand for around £100. His gym friends have even given the phenomenon a name—"proteinflation"—a term likened to inflation but specific to protein products. For younger users, the cost is also a challenge. Evie Lewis, a 19-year-old student at the University of Manchester, started using protein powder recently but finds the price of a 420g tub at £32.99 difficult to manage. To stretch her supply, she has started rationing her use. Meanwhile, Max Longman, a 32-year-old real estate professional from Manchester, has been taking protein supplements for a decade. He reports that his monthly spending has increased from £45 to £60, and he now turns to high-protein foods like yogurt as a more affordable alternative. The surge in demand for protein supplements is partly due to the popularity of weight-loss medications like Wegovy and Mounjaro, which encourage users to maintain a high-protein diet while reducing calories. However, the supply of key ingredients, such as whey protein derived from milk, has struggled to keep up. According to Expana, a global market intelligence platform, the European wholesale price of a common high-protein whey product was 130% higher in late August 2025 than the previous year and more than four times what it was three years ago. Other dairy-based proteins have also seen significant increases, with some types rising by 60% or 80% over the same period. In response to these rising costs, manufacturers are adjusting their strategies. Some are changing their recipes to use less expensive protein sources, while others are introducing products made from alternative proteins, which can cost about half as much as whey. For example, the UK-based company Warrior has raised the price of its whey protein powder and is launching a new line using alternative proteins. These changes are also affecting other products, such as infant formula, which relies on similar protein sources. While wholesale prices for whey have started to stabilize in recent months, they are still far higher than they were in previous years. Some consumers, like Max, continue to see the value in buying supplements, while others, like Evie, may have to reconsider their use due to the high cost.