Aloe vera

What is aloe vera?

Aloe vera is a succulent plant used for thousands of years, mainly on the skin. As NCCIH explains, aloe products can come from different parts of the leaf: the clear inner gel, the yellow latex just under the skin, or the whole crushed leaf. The distinction matters. The latex contains anthraquinones, which are strong stimulant laxatives. In 2002 the FDA required manufacturers to remove aloe latex from over-the-counter laxative products because of a lack of safety data, and the International Agency for Research on Cancer classifies non-decolorized whole leaf extract as a possible human carcinogen.

What the research says

For digestion, the most relevant evidence is a 2018 meta-analysis in the Journal of Neurogastroenterology and Motility. It pooled three randomized trials with 151 people with IBS and found that aloe vera improved symptom scores and response rates compared with placebo in the short term, with no adverse events reported in those studies. Three small trials are a thin base, and products and doses varied.

NCCIH’s overall summary is more cautious: it lists IBS among conditions where there isn’t enough reliable information to say whether aloe helps. A small amount of research suggests oral aloe may lower blood sugar in people with diabetes.

Safety is the bigger story. A 2016 toxicology review by FDA scientists notes that ingesting aloe preparations has been associated with diarrhea, low potassium, darkening of the colon lining, kidney problems and hypersensitivity reactions, and that whole leaf extract showed carcinogenic activity in rats. NCCIH adds that aloe leaf extracts have been linked to cases of acute hepatitis.

How it’s used in supplements

Gut capsules usually list “aloe vera” without saying whether it is decolorized inner-leaf gel or whole leaf, or how much aloin it contains. That makes it impossible to judge either benefit or risk. If you want to try aloe, choose a product that specifies decolorized inner-leaf gel, use it short term, and talk to your doctor first, especially if you take heart, diabetes or diuretic medications.

Aloe’s laxative effect comes mainly from anthraquinones such as aloin in the latex. These compounds stimulate the colon and draw water into it, which is why aloe latex was once sold as a laxative. Stimulant laxatives can cause cramping and, with frequent use, loss of potassium and other electrolytes. Decolorized inner-leaf gel has most of the aloin removed, which is why product form matters so much.