Mace is the reddish netlike covering surrounding the nutmeg seed. Mace is used as a flavoring for many sweet dishes from the cuisines of various countries, and as a spice in many savory dishes. Mace is used for pain, stomach problems, and many other conditions, but there is no scientific evidence to support these uses. Mace contains chemicals that might affect the central nervous system. Mace might also kill bacteria and fungi.