L-Eflornithine is primarily used in the treatment of excessive facial hair growth in women, a condition known as hirsutism. It works by inhibiting the enzyme ornithine decarboxylase, which is involved in hair growth. Applied topically as a cream, it helps to slow down the growth of unwanted facial hair, making it a valuable option for those seeking a non-invasive treatment. Additionally, L-Eflornithine is also used in the management of African trypanosomiasis, or sleeping sickness, where it is administered intravenously to combat the parasitic infection by targeting the same enzyme in the parasite, thereby inhibiting its growth and replication.