Prunella vulgaris can be boiled several times for drinking.

It is generally believed that Prunella vulgaris (Xia Ku Cao) can be boiled and consumed for 2 to 3 times. Specific details are as follows:

Prunella vulgaris can typically be boiled 2 to 3 times. Each time, it should first be soaked in clean water for about half an hour, then brought to a boil over high heat and simmered over low heat for 15 to 20 minutes. It should not be boiled for too long, as this may weaken its medicinal effects. If the dosage of Prunella vulgaris is relatively small, boiling it twice is usually sufficient. For individuals with poor physical condition who wish to enhance their constitution by drinking the decoction, boiling it about three times may be appropriate.

Prunella vulgaris can be combined with other traditional Chinese herbs such as honeysuckle, chrysanthemum, dandelion, forsythia, and Scrophularia to enhance its therapeutic effects. For example, boiling Prunella vulgaris together with mulberry leaf, chrysanthemum, and Lycium berries can help clear heat and toxins and improve liver function and vision.

However, Prunella vulgaris has a cold and cool nature. Excessive or prolonged use may increase the burden on the spleen and stomach or trigger allergic reactions. It is essential to follow medical advice to ensure safe usage.