No. 1 Remedy for cold sores.

If on the lips (with no other strong symptoms). Very sensitive people who remember the smallest slights for a long time. Feel everything so acutely they tend to protect themselves by shutting themselves off. They feel worse for consolation, except from a chosen few (or one). An important remedy for silent grief (the stiff upper lip). The middle of the lower lip may be deeply cracked. Discharges like egg white. Crave salt. Better: lying down; resting sweating. Worse: heat, especially of the sun.

Natrum Mur 30c is included in the following Homeopathy World kits: