Aloe Vera

Aloe vera is a short-stemmed evergreen succulent that stores water in thick, serrated leaves. The species is thought to originate from the Arabian Peninsula, though centuries of cultivation have spread it across tropical, semi-tropical, and arid regions worldwide, and it is now a common houseplant and crop ^[3]. Each leaf holds a mucilaginous inner gel and, just beneath the rind, a layer of yellow latex; these two fractions differ sharply in chemistry and in use ^[4].

The inner gel is largely water, with polysaccharides making up most of its dry weight. The best studied of these is acemannan, an acetylated mannan closely associated with the gel's biological activity ^[5]. Alongside the polysaccharides, the gel supplies vitamins, enzymes, minerals, sterols, and other plant compounds ^[3]. The latex is rich in anthraquinone glycosides, chiefly aloin, which give it a strong laxative action and account for much of the plant's toxicity concerns ^[4].

Records of medicinal use reach back thousands of years, with the plant appearing in ancient Egyptian, Greek, and Arabic sources as a remedy for skin conditions and wounds ^[3]. Today the gel is incorporated into lotions, creams, ointments, sunburn products, shampoos, and soaps, and it is added to juices, drinks, and desserts. Purified acemannan has also been explored as a biomaterial for tissue and dental regeneration ^[5].

Clinical research has focused mainly on wound and burn care and on metabolic effects. A systematic review of controlled trials found that topical aloe vera tended to shorten healing time for first- and second-degree burns, though the authors cautioned that product variability limited firm conclusions ^[1]. A meta-analysis of oral aloe vera in prediabetic and diabetic people reported reductions in fasting blood glucose and hemoglobin A1c, while noting the need for larger, better-controlled studies ^[2]. Overall the evidence base remains uneven, with topical skin uses better supported than oral ones ^[3].

Regulatory attention has centered on the latex. In the United States the Food and Drug Administration removed aloe from over-the-counter laxative products in 2002, citing a lack of safety data ^[4]. Whole-leaf extract, which retains anthraquinones, has drawn further concern; the International Agency for Research on Cancer classified it as a possible human carcinogen (Group 2B) after rodent studies showed evidence of carcinogenic activity ^[4]. Topical use in modest amounts is generally regarded as safe, and cosmetic preparations limit residual anthraquinone content ^[4].

Aloe vera is sold fresh as whole leaves, as bottled inner-leaf gel and juice, as dried or decolorized whole-leaf extracts, and as powders and capsules; topical products range from pure gel to blended creams and sprays ^[3].

Topical aloe is very safe, with rare allergic skin reactions. Oral inner-leaf gel is generally well tolerated, but products containing aloe latex or whole-leaf extract can cause cramping, diarrhea, and electrolyte loss, and long-term latex use raises safety concerns. Oral aloe can lower blood sugar, so diabetics on medication should monitor, and it's avoided in pregnancy.