In March 2000 WDDTY (vol 10 no 12), CH of London enquired about natural treatments for cold sores.
For several years, I've found that the liquid version of Dr Edward Bach's Rescue Remedy for shock, applied in its concentrated form, stopped the herpes cold sore from developing, usually overnight.
This small bottle can be bought in health shops or even local chemists (many now stock it). It can be applied to any broken skin, but must be kept away from eyes. It can, of course, be drunk, either a few drops (concentrate) put on the tongue or a few drops in about half a teacup of water.
If you can't get Rescue Remedy in cream or liquid form, write to Bach Flower Remedies, Unit 6, Suffolk Way, Abingdon, Oxon OX14 5JX. Margaret Woolford, Clevedon