Rather than prescription or over-the-counter drugs, many of us use herbal medicines to relieve pain or treat illnesses. But a new study published in the journal Fungal Biology claims some herbal medicines are contaminated with toxic molds at levels that pose harm to human health.

Share on Pinterest High levels of toxic molds were identified among 30 samples of plants commonly used for herbal medicines. These molds could cause serious illness in humans.

Herbal medicine is described as the use of plants to treat medical conditions. According to the research team, from the University of Peshawar in Pakistan, around 64% of people use herbal medicines.

Study author Samina Ashiq says that because these medicines are natural, there is a “common misconception” that they are safe, but this may not be the case. The plants may be subject to contamination by molds that produce mycotoxins.

At high levels, these mycotoxins can trigger adverse effects in humans. They have been linked to liver cancer, kidney damage, reproductive disorders and immune system suppression.

Despite the risks herbal medicines may pose, however, they are not well regulated. The Food and Drug Administration (FDA) deem herbal medicines as food products, therefore they are not subject to the same testing, manufacturing and labeling standards as prescription and over-the-counter drugs.

This is the same for most countries worldwide, including Pakistan, where the majority of people use herbal medicines. “It’s common to use medicinal plants in our country and to buy from local markets and shops,” says Ashiq.