Research on the use of aloe for certain conditions shows:

Burns and wounds. Putting aloe gel on first- and second-degree burns and wounds may speed healing. There's not enough proof to know if aloe gel helps sunburns heal.
Acne. Research suggests that using aloe gel with the prescription acne medicine tretinoin (Retin-A, Atralin, others) might work better than the acne medicine alone. You put the gel and the medicine on your skin.
Psoriasis. Aloe extract cream might ease symptoms of mild to moderate psoriasis. You might need to use the cream several times a day for a month or more to see your skin get better.
Herpes simplex virus. Putting a cream that has aloe extract on the skin might help sores heal sooner.
Oral lichen planus. This ongoing condition may cause irritated swollen tissues inside the mouth. Research suggests that putting aloe gel on the sores for eight weeks might help ease the symptoms.
Constipation. It's not clear whether taking aloe latex by mouth treats trouble passing stool, called constipation. Aloe latex acts as a laxative. But aloe latex also may cause stomach cramps and loose stools.