A month is quite a long time to be suffering from a cough so it may be that you need to visit your doctor too, just to get checked out.
There are no restrictions on using Bronchoforce long term but we would say only to use it as long as you feel it is helping.
If your cough is mucus-producing then this is the right product to be using but, if your virus has left you with more of a tickly, irritating cough, then I would recommend Bronchosan instead.
Do you have questions? Please feel free to ask.
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