MUMBAI: Six months after the British Medical Association rubbished homeopathy as witchcraft with no scientific basis, IIT scientists have said the sweet white pills work on the principle of nanotechnology.

Homeopathic pills containing naturally occurring metals such as gold, copper and iron retain their potency even when diluted to a nanometre or one-billionth of a metre, states the IIT-Bombay research published in the latest issue of 'Homeopathy', a peer-reviewed journal from reputed medical publishing firm Elsevier.