Dubbed the 2025 Cotton Rankings, the report by Solidaridad and Good On You analysed the cotton sourcing of the world's top 100 fashion brands. It revealed a significant increase in synthetic fibre use, largely at the expense of cotton.

Key findings from the cotton rankings report

• There is an increasing usage of synthetic fibres with fast-fashion giants such as Shein reportedly sourcing 82% of its fibres synthetically
• Even those brands that claim to use high proportions of certified cotton often use relatively little cotton overall – significantly reducing their positive impact
• Transparency is also lacking in the fashion industry, with 29 of the 100 fashion brands disclosing exactly how much cotton they consume, and only 35 provide information regarding their specific certification type.

The rankings also reveal that most brands are not open about their cotton sourcing details.

This lack of disclosure, coupled with the promotion of 'sustainable fibres' without corresponding data on total volumes used, leaves consumers and researchers in the dark and unable to substantiate sustainability claims.

Consequently, over two-thirds of the global fashion market is essentially blindfolded regarding one of its most essential raw materials.

Good On You co-founder Sandra Capponi said: “What makes this partnership powerful is how Good On You’s sustainability assessments, including deep analysis of material sourcing and certification claims, complement Solidaridad's focused cotton expertise, revealing patterns invisible in traditional reporting.”

Slow advancements in certified cotton sourcing

The study found little progress on certified cotton sourcing between the 2023 ranking and 2025.

Out of the companies ranked, 31 use more than 50% cotton in their operations, and only 17 of these companies assert that over half of their cotton is certified.

Prominence of synthetic fibres

While cotton is still a key component for approximately half of the brands analysed, the use of synthetic fibres is significantly prevalent.

Out of the companies evaluated, a mere 31 use over 50% cotton in their operations, with only 17 claiming that more than half of their cotton is certified. Furthermore, an alarming 26 brands have been found to be reliant on synthetic fibres for over half of their needs. The remaining 43 brands exhibit a diverse fibre usage, incorporating both natural and synthetic materials.

Key recommendations

The report calls for urgent action from fashion brands to increase transparency about their buying habits and a commitment to shift towards 100% certified cotton.