I have started taking mucinex here and there when I have alot of mucus and it helps me breath better.
It seems you already have the answer to this question, if Mucinex is helping you!
Mucinex is designed to treat symptoms, not the underlying problem. So, it shouldn't cause any harm to take it if you have asthma, and it may indeed help you feel better. But, by itself, it won't control your asthma.
So, just be sure that you also keep taking your prescribed asthma medicine too. And keep working as hard as you can to avoid your known asthma triggers. Those are the keys to asthma control.
Also, be aware that excess mucus can also be a sign of lung infection and with your asthma, you are at risk for infection. So watch for thick, yellowish or greenish mucus, or even blood-tinged mucus. These could be signs of infection, especially if you also begin to run a fever. "Asthma mucus" should be clear and fairly colorless. If you do think you might have an infection, be sure to call your doctor.
To your health,