Yes, particularly if you're over 40 and have a history of heart disease or high blood pressure, or both.
Eating more than 57g (2 ounces) of black liquorice a day for at least 2 weeks could lead to potentially serious health problems, such as an increase in blood pressure and an irregular heart rhythm (arrhythmia).
For most people, liquorice found in foods is safe to eat and safe when consumed in large amounts in medicines for short periods of time.
General health advice about black liquorice
No matter how old you are, you should avoid eating large amounts of black liquorice over a short space of time.
If you have been eating a lot of black liquorice and have heart palpitations, muscle weakness or other health-related problems, stop eating it immediately and seek medical advice.
Black liquorice can interact with some medications, herbs and dietary supplements.
Get advice from a GP or pharmacist if you have questions about possible interactions with a medication or supplement you're taking.