Aloe vera is a succulent plant of the genus Aloe. Aloe vera is an evergreen perennial native to the Arabian Peninsula but also grows in tropical, subtropical, and arid climates around the world. It has been cultivated for commercial products, primarily as a topical treatment for centuries. The species is considered decorative and is often grown in potted plants indoors.

Aloe vera leaves contain aloin, a toxic compound. Aloin, a compound found in the semi-liquid latex of some species of aloe, was a common ingredient in over-the-counter (OTC) laxatives in the United States until 2002, when the U.S. Food and Drug Administration (FDA) banned its use due to the manufacturer's failure to provide necessary safety data. Aloe vera is potentially toxic, and certain doses of aloe vera can cause adverse effects whether taken orally or applied topically. Although toxicity may be less after processing to remove aloin, ingesting large amounts of aloe vera may cause adverse effects such as abdominal pain, diarrhea, or hepatitis. Long-term ingestion of aloe vera (1 gram per day) may cause adverse effects, including hematuria, weight loss, and heart or kidney disease. Oral aloe extract may cause acute abdominal pain and cramping, and long-term use may even cause hepatitis. It is contraindicated during pregnancy. Some people may have an allergic reaction to aloe applied to the skin.

The yellow latex in aloe is used to make commercial products. Aloe latex can be used alone or with other ingredients to make products for oral relief of constipation. Aloe latex is available in a dried form, called resin, or as "aloe vera juice." However, aloe latex or whole leaf extract may be toxic if ingested in large doses or over a long period of time. Small amounts of aloe vera are probably safe for external use.