Can anti fungus work for black toe nails?

If the black toe . Are fungus.....They may be secondary to a subungual hematoma or blood under the nail in which case the medication will do nothing. Topical medications only work about ten percent of the time so you need to keep that in mind as well.
Sometimes. . Sometimes the darkness is a result of mold in addition to fungus. You may need a pill to get rid of the darkness. If its been there for a very long time it may not be cured.