A new U.S. study has found that liquorice supplements could pose a potential health risk by interacting with medications.

Presented at the 254th National Meeting & Exposition of the American Chemical Society, the study looked at the effect of three types of liquorice on the body's ability to metabolize and transport drugs.

The results are particularly important for menopausal women, who often take liquorice supplements to treat hot flashes and other symptoms.

"Concerns about the risk of stroke and breast cancer associated with conventional hormone therapy are prompting women to seek alternatives," explained Richard B. van Breemen, from the University of Illinois, with some opting to take botanical dietary supplements, including liquorice, on a daily basis.

Liquorice is known to be harmful in large doses, even in candy. The FDA warns that excessive consumption in a short period of time can lead to irregular heart rhythm and muscle fatigue.

The research team also wanted to determine if even the small amounts found in dietary supplements could negatively impact health by interacting with medications.

"The liver has enzymes that process medications, and if these enzymes are induced or inhibited, the drugs will either be processed too quickly or too slowly, respectively," said van Breemen.

The team analyzed how three types of liquorice -- two North American species, Glycyrrhiza uralensis and G. inflata, and a European species called G. glabra -- affected these liver enzymes and drug metabolism.

Their research showed that all three species inhibit several of the enzymes. However, only G. uralensis and G. inflata extracts were found to induce some of these enzymes.

The researchers concluded that the North American G. uralensis and G. inflata were more likely to interfere with drug metabolism, compared to the European G. glabra.

As most supplements don't list the species in their ingredient labels, consumers cannot yet use this information to determine whether those they take might potentially interact with other drugs.

However, the team plan to conduct further research and potentially develop their own G. glabra-based liquorice supplement, which would be safe and effective for menopausal women.