No study has tested it. Here’s what is known.
No study has tested mullein as a lung “detox”, and no study has measured lung function after taking it. The lungs clear themselves through mucus and tiny hair-like cilia; smoke slows that down. No product has been shown to reverse that.
Some people say mullein tea or drops make a cough feel looser or a throat feel softer. That is a real experience worth taking seriously — and it is also the kind of effect a placebo produces, which is why it needs a proper test.
Evidence checked 2026-10-21. Grades are calculated from the studies listed, by fixed rules.
No human trial has tested it. The EU herbal monograph lists relief of sore throat with dry cough and cold as a TRADITIONAL use — based on long-standing use, not on trials.
No human trial has tested it, and no study has measured lung function after mullein. Nothing undoes smoking damage except stopping.
Stopping smoking is the only thing shown to let the lungs recover. Free help to stop smoking: smokefree.gov · 1-800-QUIT-NOW (1-800-784-8669).
Our mullein study will test the cough question directly.