What are the potential health risks associated with aloe vera?

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

The aloe vera gel is characterised by an exceptionally rich composition, comprising 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 image, the question of the risks of aloe vera and its potential adverse effects deserves closer examination.

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

Its anti-inflammatory, antimicrobial and regenerative properties support the skin’s natural repair mechanisms and account for its frequent inclusion in the treatments formulated for sensitive or compromised skin. When used correctly, there are therefore few risks associated with aloe vera at the cutaneous level, and this ingredient can be suitable for all skin types, including expectant women. It is thus entirely feasible to use aloe vera gel during pregnancy, provided that the products are formulated and purified in accordance with current standards. However, it is advisable to avoid its use during breastfeeding to prevent ingestion by the infant.

This does not, however, mean that the side effects of aloe vera gel are non-existent. A few allergic reactions have been reported in the scientific literature, presenting as contact dermatitis, erythema or, more exceptionally, phototoxicity in sensitive individuals. One case report, for example, describes dermatitis of the legs accompanied by eyelid erythema in a woman who had applied homemade aloe vera juice. Patch tests confirmed sensitisation 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 advisable to carry out a preliminary skin test before the first use of aloe vera gel, by applying a small amount of the product to the crease of the elbow for 24 hours. This simple practice helps to reduce the risks associated with aloe vera in individuals prone to allergic reactions. In the event of persistent redness, itching, or a burning sensation, application should be discontinued and medical advice may be sought.

Unlike topical use, aloe vera ingestion raises additional safety concerns.

Several studies have indeed reported side effects following oral consumption of aloe vera: diarrhoea, electrolyte imbalances such as hypokalaemia, renal impairment, hypersensitivity reactions and even phototoxic effects. 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 whole preparations containing latex rich in anthraquinones, notably aloin, a compound converted by the gut flora into potentially genotoxic, nephrotoxic or purgative metabolites. They explain why the hazards of drinking aloe vera gel are now under special scrutiny.

However, not all forms of aloe vera present the same profile. Toxicological studies in animals show that purified, aloin-poor gels do not induce acute toxicity or any significant genotoxic effect, even at high doses. Similarly, certain encapsulated preparations administered orally did not cause notable biological or histological alterations during subacute exposures.

These results suggest that the risks of aloe vera depend heavily on the quality of the extract, its composition and the dose consumed, emphasising the importance of strict regulation of dietary supplements.

As a precautionary measure, the oral consumption of aloe vera remains inadvisable in several sensitive situations, notably during pregnancy or while breastfeeding. Indeed, the latex from aloe vera, commonly ingested for its laxative properties, is liable to induce uterine contractions and lead to a miscarriage. The same applies during lactation: aloin from aloe vera, responsible for its laxative effect, can be transferred into breast milk and affect the infant’s health, causing diarrhoea or dehydration. This is also why the topical application of aloe vera gel is not recommended for breastfeeding women.

Whilst the topical application of aloe vera gel is generally regarded as safe, its ingestion should be approached with greater caution, and we recommend ensuring that only purified, high-quality aloe vera is consumed.

• 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).