Former FDA scientist says agency approved Zyn without fully understanding pouch material

A former FDA scientist says the agency approved Zyn nicotine pouches for sale without fully understanding what the product was made of, and whether the pouch material could release microplastics.

Christy Leppanen, who worked for the FDA’s Center for Tobacco Products, said her concerns grew after she carried out a series of informal tests at home while the agency was still reviewing the product. Leppanen had led a project looking at possible microplastics exposure, and she said the issue became more pressing as Zyn moved closer to authorization.

The FDA spent four years reviewing Zyn nicotine pouches before allowing them on the market. During that time, and not long before the agency approved them for sale, Leppanen said she began to question whether regulators fully understood the addictive product they were preparing to green-light.

Leppanen said one point of confusion centered on the physical behavior of the pouches. A scientist who had worked on an environmental assessment of Zyn had repeatedly told her the pouches melt in the mouth. But during a public health conference in late 2024, Leppanen said she spoke with an academic who reinforced her understanding that they do not melt.

After the conference, Leppanen said she stopped at the Mall of America and bought a can of menthol-flavored Zyn to test for herself. Back at home, she tried a range of simple experiments in her kitchen. She put the pouches in her mouth, soaked them in a cup with saliva, heated them in the microwave, crushed them, and sucked them. According to Leppanen, they did not dissolve.

Her account raises questions about what the FDA knew, and when, as it reviewed a product that was eventually authorized for sale while still under evaluation. The source does not say what, if any, formal testing the agency had completed on the pouch material before approval, or whether any microplastics risk was included in the final authorization decision.

The concern described by Leppanen is specific to the pouch material itself. She said her tests led her to wonder whether the material could shed microplastics, but the source does not report a conclusion from the FDA or from any independent study about whether that occurred.

Zyn nicotine pouches are described in the source as addictive products. The article does not provide details about the product’s ingredients, composition, or manufacturing process, and it does not state whether the FDA later changed its position on the pouches after Leppanen’s observations.

The report is based on Leppanen’s description of her experience during the FDA review period and on the broader fact that the agency allowed stores to sell Zyn while it continued evaluating the product. It also notes that Leppanen’s work at the FDA’s tobacco center included a project focused on the potential for microplastics exposure.

The source does not say whether Leppanen’s kitchen tests were part of any official FDA analysis, whether they were shared internally, or whether they affected the agency’s decision. It also does not report any response from the FDA, Zyn’s maker, or other scientists involved in the review.

The story was published in partnership with The Examination.