Dorma night-time tea contains Common heather (Calluna vulgaris), Yarrow (Achilla millefolium) flowers and Silverweed (Potentilla anserina). These are all believed to have a calming effect and are popular remedies for insomnia. Common heather is also believed to have cleansing, bactericidal and analgesic properties. Yarrow is said to be fortifying, relaxing and to dilate the blood vessels and thus to reduce blood pressure. Silverweed is considered to calm the nerves and to have a muscle-relaxing effect.