Always buy herbal teas from a reputable supplier or better still make your own. If you are using soft leaves and flowers make an infusion. If you are using tough, woody, very fluffy herbs or the roots you will need to make a decoction.
So how much should you drink?
Aim to drink about a quarter of a pint three times a day. Start off with smaller amounts, if the tea disagrees with you then try a weaker solution or change the remedy
Make smaller quantities and try a teaspoon (5ml) at a time for small children
How can I make it drinkable?
Flavour herb tea with min and thyme or a little honey or apple juice