A Fertilizer Made From Human Urine Is Coming to the US

Nitrogen fertilizer is a cornerstone of modern agriculture, but the rising costs of key ingredients, including nitrogen itself, have made it more expensive than ever. One company believes it has found a more sustainable, affordable way to make fertilizer — by recycling human urine.

Aurin is a universal fertilizer from Swiss company VunaNexus made with processed human urine. It originated as a South African research initiative launched more than a decade ago to develop an affordable sanitation system that could transform human urine into fertilizer.

 “The fertilizer has the same effect as other fertilizers, it’s completely depolluted, and it doesn’t smell — people always ask about the smell,” says David de Chambrier, co-founder of VunaNexus. Aurin has already been approved for use in several European countries and, de Chambrier reports, is now being shipped to the United States.

Using human urine as fertilizer may sound surprising, but the idea is more practical than it first appears. Sustainability experts say products like this could play an important role in reducing waste and recovering valuable nutrients. Here's why.

How does Aurin turn urine into fertilizer?

Urine contains nutrients — particularly nitrogen, phosphorus, and potassium — that plants need to grow. Most commercial fertilizers use synthetic nitrogen derived from the nitrogen in air. But using waste as fertilizer is an idea that’s about as old as agriculture itself. In the United States, early commercial fertilizers included materials such as guano (accumulated seabird droppings imported from Peru), fish scraps, bones, wood ash, slaughterhouse byproducts, as well as treated human waste.

Continuing that tradition, Aurin processes human urine to retain the valuable nutrients used in fertilizer and to remove drug residues, hormones, and germs. First, urine is collected in water-free urinals or special tanks that divert urine, de Chambrier explains.

From there, the urine goes through a process that binds the desired nutrients and converts unwanted ammonia to nitrate with the help of two types of bacteria. “Ammonia is what smells bad when you urinate,” de Chambrier says. “But if you treat the ammonia, it doesn’t smell bad anymore.”

The final steps are filtration and distillation. During this stage, the liquid is pushed through a carbon filter to remove drug residues, hormones, and pollutants. From there, the liquid is distilled about 20 times to remove excess water and concentrate the final product, de Chambrier explains. “The liquid is completely pasteurized as well,” he says. 

Why make fertilizer with urine?

Nitrogen fertilizer prices have climbed in recent years, putting added pressure on growers. “Recent events like the global pandemic and geopolitical conflicts interrupted global supply chains, making nitrogen fertilizer more costly,” says Kang Sun, PhD, assistant professor of Civil, Structural and Environmental Engineering at University at Buffalo. 

Using urine to make fertilizer helps drive down costs and support sustainability in fertilizer production, says Rachel A. Meidl, LPD, MEd, deputy director of the Center for Energy Studies at Rice University’s Baker Institute for Public Policy. 

“At its core, sustainable fertilizers are about recovering valuable resources that are currently being discarded,” she says. “Human urine contains […] the same nutrients found in conventional fertilizers.” In most modern wastewater systems, those nutrients are discarded along with other waste. Instead, they are a resource that can be recovered and reused, Meidl says. 

“There is also growing recognition that many of the materials we rely on for food production are not unlimited,” Meidl says. “Phosphorus, for example, is a critical nutrient with geographically concentrated reserves, while nitrogen fertilizer production is energy-intensive and closely linked to natural gas markets.” Recovering nutrients from waste streams can help reduce dependence on new resources while creating more resilient nutrient systems, Meidl says. “From a broader sustainability perspective, the concept reflects a shift away from traditional linear models toward finding ways to keep valuable materials in productive use for longer,” she adds. 

Is urine-based fertilizer currently in use?

Aurin is approved for use in Switzerland, Liechtenstein, and Austria, where it's being adopted by municipalities, businesses, and educational institutions. Current users include the Swiss city of Winterthur, the city of Lausanne, and the Centre de Formation Professionnelle Nature et Environnement, an agricultural school in Switzerland.

The company's next focus is viticulture. "We are just starting a three-year program to use Aurin on vineyards at Changins, a prestigious wine university in Switzerland," de Chambrier says. 

Aurin isn't the only urine-based fertilizer company out there. The UK-based NPK Recovery converts urine collected at festivals, sporting events, and temporary sites, while Oatly supports a project called Pee for the Planet, which turns urine into fertilizer pellets.

Can urine-based fertilizer go mainstream?

Aurin’s production depends on collecting urine through dedicated systems, meaning that adoption requires the right infrastructure and user participation. De Chambrier says the company is already working to build that network.

“We have a lot of neighborhoods, private banks, and major industry and office buildings in Paris, Geneva, and Zurich that are starting to install these technologies,” he says. 

Another challenge is ensuring the recovered fertilizer consistently meets health, environmental, and agricultural standards, Meidl adds. “There are also practical considerations, such as collection, transport, treatment, storage, and distribution, all of which require infrastructure and energy,” she says. “The environmental benefits ultimately depend on how efficiently the entire system operates collectively.”

Sun notes that human urine isn't the only — or even the largest — potential source of recovered nitrogen: “Nitrogen from livestock waste is a much larger nitrogen source, although probably less eye-catching than using human urine,” he says. 

Meidl adds that public perception will play a major role in determining whether recycled fertilizers gain widespread acceptance. “Even if the science and treatment processes demonstrate that the final product is safe and effective, public acceptance can influence adoption,” she says. “Sustainability outcomes are determined by the performance of the entire system, not simply by the origin of the material being recovered.”