The side effects of HALLS cough drops are numbness in your mouth or throat.
Taking too many HALLS cough drops may cause menthol poisoning and cause other side effects.
Other side effects of menthol poisoning and taking too many HALLS cough drops include.
Nausea and vomiting.
Dizziness.
Nervousness.
Nystagmus.
Possible coma.
And in severe menthol poisoning death may occur.
It's rare to have side effects of HALLS cough drops and other cough drops when taken as directed.
However some people are sensitive to the ingredients in the cough drops and may experience side effects which are often not serious and go away on their own.
You should not take a whole bag of HALLS cough drops in 24 hours as it could make you sick.
And while negative symptoms from consuming too many cough drops can occur, you aren't likely to ingest enough cough drops to cause any serious harm.
Although, you should always read the label and try not to exceed the recommended dose of the cough drops.
If you're worried about overdosing on cough drops, look for cough drops that don't contain menthol.