What are the potential dangers of aloe vera?

The aloe vera is a succulent plant belonging to the family Asphodelaceae. Adapted to hot, arid climates, it stores water in its fleshy leaves, allowing it to endure dry environmental conditions. The leaf contains two distinct fractions: on one hand, the latex—a yellowish, bitter sap located beneath the rind—and on the other, the gel—a translucent, viscous substance contained at the core of the leaf tissue. These two substances have very different chemical compositions and applications: the latex has historically been taken orally for its intestinal effects, while the gel is primarily used in cosmetics and dermatology.

The aloe vera gel is characterized by an exceptionally rich composition, containing over a hundred biologically active constituents: polysaccharides, amino acids, lipids, vitamins, minerals, and phenolic compounds. Among these, certain polysaccharides such as acemannan or mannose-6-phosphate are linked to its hydrating, soothing, and restorative properties for the skin.

However, despite this very positive perception, the question of aloe vera’s risks and its potential adverse effects warrants a more detailed examination.

When applied topically, aloe vera gel is generally considered safe and well tolerated.

Its anti-inflammatory, antimicrobial, and regenerative properties support the skin’s natural repair mechanisms and explain its frequent inclusion in skincare products intended for sensitive or compromised skin. When used properly, there are therefore few risks of aloe vera topically, and this ingredient can be suitable for all skin types, including pregnant women. It is therefore entirely possible to use aloe vera gel during pregnancy, provided the products are formulated and purified in accordance with current standards. However, it is best to avoid use during breastfeeding to prevent the infant from ingesting it.

This does not mean, however, that the side effects of aloe vera gel are nonexistent. Rare allergic reactions have been described in the scientific literature, manifesting as contact dermatitis, erythema, or, more exceptionally, phototoxicity in susceptible individuals. A clinical case report, for example, described dermatitis of the legs accompanied by eyelid erythema in a woman who had applied homemade aloe vera juice. Patch tests confirmed sensitization to the plant. These observations highlight that the adverse effects of aloe vera primarily involve crude or artisanal preparations, potentially contaminated with irritating latex compounds, whereas properly purified cosmetic extracts are much better tolerated.

At Typology, we use exclusively purified aloe vera, free of latex.

As a precaution, it is still recommended to perform a preliminary skin test before the first use of aloe vera gel, by applying a small amount of product to the flexor surface of the elbow for 24 hours. This simple procedure helps minimize the risk of allergic reactions to aloe vera in individuals predisposed to such responses. If redness persists, itching develops, or a burning sensation occurs, discontinue use and consider seeking medical advice.

Unlike topical use, ingesting aloe vera poses greater safety concerns.

Several studies indeed report side effects of oral aloe vera consumption: diarrhea, electrolyte imbalances such as hypokalemia, kidney damage, hypersensitivity reactions, and even phototoxicity. Anses even classifies aloe vera leaf extract as a possible human carcinogen (Group 2B), based on results observed in animal studies. These data mainly concern full-spectrum preparations containing latex rich in anthraquinones, notably aloin, a compound that the intestinal flora converts into potentially genotoxic, nephrotoxic, or purgative metabolites. They explain why the risks of drinking aloe vera gel are now under particular scrutiny.

However, not all forms of aloe vera exhibit the same profile. Animal toxicology studies have shown that purified, low-aloin gels induce neither acute toxicity nor significant genotoxic effects, even at high doses. Likewise, certain encapsulated formulations tested orally did not produce notable biological or histological changes during subacute exposures.

These findings suggest that the risks associated with aloe vera depend heavily on the extract’s quality, composition, and the dose consumed, emphasizing the importance of strict regulation of dietary supplements.

As a precautionary measure, the oral consumption of aloe vera is discouraged in several sensitive situations, notably during pregnancy or while breastfeeding. Indeed, the latex from aloe vera, typically ingested for its laxative effect, may induce uterine contractions and lead to miscarriage. The same applies during the breastfeeding period: aloin from aloe vera, responsible for its laxative action, can pass into breast milk and affect the infant’s health, causing diarrhea or dehydration. This is also why topical application of aloe vera gel is not recommended for nursing women.

Although topical application of aloe vera gel is generally safe, oral ingestion requires greater caution, and we recommend consuming only purified, high-quality aloe vera.

• SELORES M. & al. Allergic contact dermatitis to aloe vera. Contact Dermatitis (2007).

• BELAND F. A. & al. An evaluation of the biological and toxicological properties of Aloe Barbadensis (Miller), aloe vera. Journal of Environmental Science and Health (2007).

• MEI N. & al. Aloe vera: A review of toxicity and adverse clinical effects. Journal of Environmental Science and Health (2016).

• SHI W. & al. Safety evaluation of aloe vera soft capsule in acute, subacute toxicity and genotoxicity study. PLOS One (2021).

• CHHOKAR V. & al. The dark side of miracle plant aloe vera: A review. Molecular Biology Reports (2022).

• OGWANG P. E. & al. Acute and sub-acute oral toxicity of aqueous whole leaf and green rind extracts of Aloe vera in Wistar rats. BMC Complementary Medicine and Therapies (2022).

• BAUTER M. R. & al. Evaluation of 90-day repeated dose oral toxicity of an aloe vera inner leaf gel beverage. Food and Chemical Toxicology (2024).