In 2015, Philip Siefer and Waldemar Zeiler were in the middle of crowdfunding their new business venture. “We kept hearing the same question from people who were donating money,” says Siefer. “Are the condoms vegan? We didn’t even realise ourselves that condoms usually contain an animal protein to make the latex softer.”

The Berlin-based entrepreneurs were looking to capture a slice of the $8bn global condom market by appealing to eco-conscious customers. To their surprise, this group of consumers is remarkably large – and four years in, their brand of sustainable, vegan hygiene products is raking in a yearly revenue of around €5 million.

Their company, Einhorn, means unicorn in German. Imagery aside, the entrepreneurs say it’s actually a play on the term used to describe $1bn start-up giants like Airbnb and Deliveroo. While Siefer and Zeiler aren’t in the three-comma club yet, building sustainability into the core of their business has been successful, and not just because it’s popular with consumers. Rather, building sustainable values into their brand has opened doors within the business community that otherwise would have been more difficult to access.

Contains no animal products

Condoms are Germany’s second-favourite form of contraception, after the pill, but it was while shopping with his girlfriend that Siefer was struck by how outdated the branding seemed. He felt that today’s consumers might embrace a new eco-friendly alternative and, after originally dismissing the idea, Zeiler jumped on board, deeming the product ideal for ecommerce. The pair wanted to create a business that was fair and sustainable, not only for the planet but also for its workers.