Hi mum, I haven’t personally used that exact cough syrup before, but I’ve seen it being given for chesty coughs to help loosen phlegm. Since you’ve been coughing for over a month already, I think it’s better not to just keep switching syrups and instead go back to see a doctor again to check what’s causing the long cough. Sometimes prolonged cough can be due to lingering infection, post-nasal drip, or even asthma-like irritation, so better to get it properly reviewed by expert.