This site's own mechanism sequence opens with this specific step — worth understanding it on its own before the four steps that follow.
This site describes it directly: Mullein leaf, long used in traditional respiratory formulas, is chosen to help support the body's normal clearing of mucus so airways feel more open.
Worth noting this site places airway clearing first, ahead of irritation-soothing, mucus-breakdown, antioxidant-defence and oxygen-utilisation — worth reading that order as this site's own stated priority sequence.
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