This fact sheet provides basic information about aloe vera—common names, what the science says, potential side effects and cautions, and resources for more information.
Aloe vera’s use can be traced back 6,000 years to early Egypt, where the plant was depicted on stone carvings. Known as the “plant of immortality,” aloe was presented as a burial gift to deceased pharaohs.
Historically, aloe was used topically to heal wounds and for various skin conditions, and orally as a laxative. Today, in addition to these uses, aloe is used as a folk or traditional remedy for a variety of conditions, including diabetes, asthma, epilepsy, and osteoarthritis. It is also used topically for osteoarthritis, burns, sunburns, and psoriasis. Aloe vera gel can be found in hundreds of skin products, including lotions and sunblocks. The Food and Drug Administration (FDA) has approved aloe vera as a natural food flavoring.
Aloe leaves contain a clear gel that is often used as a topical ointment. The green part of the leaf that surrounds the gel can be used to produce a juice or a dried substance (called latex) that is taken by mouth.
What the Science Says
Aloe latex contains strong laxative compounds. Products made with various components of aloe (aloin, aloe-emodin, and barbaloin) were at one time regulated by the FDA as oral over-the-counter (OTC) laxatives. In 2002, the FDA required that all OTC aloe laxative products be removed from the U.S. market or reformulated because the companies that manufactured them did not provide the necessary safety data.
Early studies show that topical aloe gel may help heal burns and abrasions. One study, however, showed that aloe gel inhibits healing of deep surgical wounds. Aloe gel has not been shown to prevent burns from radiation therapy.
There is not enough scientific evidence to support aloe vera for any of its other uses.
Side Effects and Cautions
Use of topical aloe vera is not associated with significant side effects.
A 2-year National Toxicology Program (NTP) study on oral consumption of non-decolorized whole leaf extract of aloe vera found clear evidence of carcinogenic activity in male and female rats, based on tumors of the large intestine. According to the NTP, from what is known right now there is nothing that would lead them to believe that these findings are not relevant to humans. However, more information, including how individuals use different types of aloe vera products, is needed to determine the potential risks to humans.
Abdominal cramps and diarrhea have been reported with oral use of aloe vera.
Diarrhea, caused by the laxative effect of oral aloe vera, can decrease the absorption of many drugs.
People with diabetes who use glucose-lowering medication should be cautious if also taking aloe by mouth because preliminary studies suggest aloe may lower blood glucose levels.
There have been a few case reports of acute hepatitis from aloe vera taken orally. However, the evidence is not definitive.
Tell all your health care providers about any complementary health practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care. For tips about talking with your health care providers about complementary and alternative medicine, see NCCAM's Time to Talk campaign.
Sources
Aloe. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on May 4, 2009.
Aloe (Aloe vera). Natural Standard Database Web site. Accessed at www.naturalstandard.com on May 4, 2009.