You can add honey with or instead of ginger.

Evaluations of thyme extract effects in human normal bronchial and tracheal epithelial cell lines and in human lung cancer cell line –

– Efficacy and tolerability of a fluid extract combination of thyme herb and ivy leaves and matched placebo in adults suffering from acute bronchitis with productive cough. A prospective, double-blind, placebo-controlled clinical trial–

– Cough medicines are a waste of money admits NHS – Independent:

Les sirops contre la toux ne servent à rien – Nouvel Obs: