The HMPC conclusions on the use of certain thyme and primula root preparations for productive coughs are based on their 'well-established use'. This means that there are bibliographic data providing scientific evidence of their effectiveness and safety when used in this way, covering a period of at least 10 years in the EU.

In its assessment, the HMPC considered a number of clinical studies with thyme and primula root showing that these medicines help reduce coughs in adults.

The HMPC conclusions on the use of certain other thyme and primula root preparations for coughs associated with colds are based on their 'traditional use'. This means that, although there is insufficient evidence from clinical trials, the effectiveness of these herbal medicines is plausible and there is evidence that they have been used safely in this way for at least 30 years (including at least 15 years within the EU). Moreover, the intended use does not require medical supervision.

In its assessment, the HMPC also considered clinical studies with thyme and primula root medicines in children. However, firm conclusions could not be drawn as these studies did not use a control group. Therefore, the HMPC conclusions on the use of these thyme and primula root medicines for coughs associated with colds are based on their long-standing use.

For detailed information on the studies assessed by the HMPC, see the HMPC assessment report.