Hello Isabella, and thank you for your patience in waiting for my response.
NAC (N Acetyl Cysteine) is an amino acid, which the body converts to glutathione. Glutathione is an antioxidant, which is thought to have a beneficial effect in the lungs, relieving inflammation (which frequently accompanies infections.) It also functions as a mucolytic, helping to thin mucus, which people with bronchiectasis usually have problems expelling. Thinning and expelling the mucus is crucial as it provides an ideal growth medium for bacteria in the dark, warm and moist environment in our lungs.
A trial is underway studying the effects of glutathione to try to quantify the benefits more exactly. I believe results are due in 2025 sometime.

What do I find? That using the combination of inhaler, NAC, glutathione, 7% saline, exercise and airway clearance (described above in my response to ling) I have managed to stay quite healthy for the past 4 years. I have had to resort to nebulized levalbuterol, oral & nebulized steroids and short-term antibiotics just a few times. My Bronchiectasis is described as moderate, complicated by moderate asthma, and I was on antibiotics for 1 1/2 years in 2018-2019 without ever getting a clean sputum culture, but my lung condition did improve.

Everyone is different, so you must work with your doctors to find a plan that keeps you as healthy as possible. What is your current routine?
Sue