Thinx launched as a direct-to-consumer brand in 2013, helping to put reusable absorbent underwear in the mainstream consciousness. In 2019, K-C purchased a $25 million piece in the company before acquiring a majority stake in February 2022.In recent years, the brand has made moves to make its products more affordable and accessible, selling in Walmart, Target and on Amazon. It also launched a lower-priced line in early 2023 called Thinx for All.

In January 2023, Thinx, has settled a class action lawsuit worth up $5 million after plaintiffs found thatthird-party testing on the underwear revealed the presence of short chain per-and polyfluoroalkyl substances (PFAS), human-made chemicals that are found in many consumer and industrial products, do not easily break down and have been linked to adverse health effects.

Thinx denied these allegations saying that PFAS have never been part of its product design and that it will continue to take measures to ensure the chemicals are not added to its products. However, the lawsuit alleges that, despite the fact that PFAS and other environmental toxins are present in a wide range of consumer products, Thinx misled consumers, marketing itself as an “organic, sustainable and nontoxic” alternative to traditional one-use menstrual products, including pads and tampons. This comes at a time when a growing number of menstruating people are proactively seeking out safer, more environmentally friendly products.