Homeopathy is based on a principle known as ‘the law of similars’ or ‘like cures like’. This law states that a substance that can cause a disease can also relieve it. For example, the remedy Allium Cepa, made from onions, may help with streaming nose and eyes. The remedies are very dilute in order to avoid unwanted side-effects. Homeopathic remedies come in pillule form and are taken orally. Remedies are available as liquids for babies and young children.