There is no real evidence that aloe vera (Aloe barbadenis) helps the skin in any significant way, but it’s not a throwaway ingredient. Some brands use aloe in place of water in their products, but aloe is actually 99.5% water. 
There is research indicating that isolated components of aloe vera, such as glycoprotein, can have some effectiveness for wound healing and as an anti-irritant. [2, 3] However, when mixed into a cosmetic product, it is doubtful that those qualities remain, although it may still play a role in binding moisture to skin.  In pure form, aloe vera’s benefits on skin are probably its lack of occlusion and the refreshing sensation it provides. Aloe serves as a water-binding agent for skin due to its polysaccharide (complex carbohydrate) and sterol content. (An example of a sterol that’s beneficial for skin is cholesterol.) Although research has shown aloe also has anti-inflammatory, antioxidant, and antibacterial qualities, no study has proven it to be superior to other ingredients with similar properties, including such ingredients as vitamin C, green tea, pomegranate, and many other antioxidants.
- Surjushe A, Vasani R, Saple D. Aloe vera: a short review. Indian J Dermatol.. 2008;53(4):163- 6.
- Reynolds T, Dweck A. Aloe vera leaf gel: a review update.. J Ethnopharmacol.. 1999;68(1- 3):3-37.
- Lee K, Weintraub S, Yu B. Isolation and identification of a phenolic antioxidant from Aloe barbadensis.. Free Radic Biol Med. 2000;28(2):261-5.
- DalBelo S, Gaspar L, Maia Campos P. Moisturizing effect of cosmetic formulations containing Aloe vera extract in different concentrations assessed by skin bioengineering techniques.. Skin Res Technol.. 2006;12(4):241-6.