People use eucalyptus (Eucalyptus globulus) for many conditions including asthma, bronchitis, plaque and gingivitis, head lice, toe nail fungus, and many others, but there is no good scientific evidence to support these uses.

The leaf contains chemicals that might help control blood sugar. It also contains chemicals that might have activity against bacteria and fungi. Eucalyptus oil contains chemicals that might help pain and inflammation. It might also block chemicals that cause asthma.