There is absolutely no evidence that aloe vera help to reduce acne.
Aloe vera or aloe barbadensisis a succulent from the Aloe family, a tropical plant which is easily grown in hot and dry climates.
The use of aloe vera is being promoted for a large variety of conditions. Topical application of aloe vera can be effective for genital herpes, psoriasis, human papilloma virus, seborrheic dermatitis, stomatitis, lichen planus, frostbite, wound healing and inflammation. Aloe can be a good addition to treatment creams, but if you look to treat your acne I would look for real anti-acne products that have proven efficacy. 🙂