What Is Aloe Vera? Leaf Structure, Gel Composition and Label Names

Aloe vera is a succulent that survives in dry regions by storing water in its fleshy leaves. Its botanical name is Aloe barbadensis Miller; its family is Asphodelaceae. The reason it is so common in skin products is this water store: the part used in cosmetics is the gel in the inner tissue of the leaf. You can find what it soothes and in which situations in the aloe vera skin benefits article; here we describe the plant and the gel themselves.

What layers does the leaf consist of?

1. Outer rind: A green protective layer, 15-20 cells thick. The plant's vascular bundles are also in this zone.
2. Latex: A bitter, yellow fluid from cells next to the vascular bundles. It carries anthraquinone derivatives such as aloin and emodin, and is the source of its strong laxative effect.
3. Inner tissue and gel: The colourless fleshy part. The dark fluid inside the cells of this zone is called gel or mucilage.

For cosmetics, the key distinction is between gel and latex. Much of the news about side effects concerns latex and oral use, not purified gel applied to the skin. In the industry, the accepted upper value for anthraquinones in purified aloe ingredients is 50 ppm. A comprehensive safety assessment also found Aloe Barbadensis ingredients safe in cosmetics to the extent they meet this condition, and noted that there is not enough data for other aloe species.

What is actually in the gel?

Fresh leaf is about 98,5% water, the gel about 99,5% water. So everything said about the plant's content rests on the remaining 0,5-1% solid portion. This portion contains:

Acemannan is the most cited polysaccharide of the gel: a long chain of mannose sugar with acetyl groups attached. In fresh leaves its molecular weight can reach about 1.000 kilodaltons. But some researchers found that the main polysaccharide is pectic substances rather than acemannan. This shows the difficulty of describing a single "aloe ingredient".

Why is not every aloe product the same?

• Plant difference: The amount of mannose-containing polysaccharide varies greatly with season, variety and growing location.
• Processing: Polysaccharides can be broken down by heat, acid and enzymes. Even the time between cutting the leaf and processing it has been shown to change wound-healing effectiveness.
• Differences between studies: A significant part of the inconsistent results in research is attributed to these production differences. The lack of a standard raw material definition makes comparison between products difficult.

A high concentration does not seem necessary either. A dried gel powder at 0,1-0,5% over 2 weeks was reported to increase upper-layer water, while not changing water loss. This result supports the interpretation that aloe works in cosmetics as a humectant.

What does Aloe Barbadensis mean on the label?

These ingredients are mostly used as skin conditioning agents and at low concentrations. Their position at the top of the list says little about the solid content of the gel, because the gel itself is almost water.

Is aloe suitable for everyone?

Applied aloe is generally well tolerated, yet redness, burning and stinging have been reported, and rarely widespread dermatitis. Allergy is thought to be mainly associated with anthraquinones. If you have a history of contact dermatitis, try the new product first on the inner arm or elbow crease, twice a day, for 7-10 days.

• Those using hydrocortisone cream: Aloe may increase hydrocortisone absorption. If you use them together, tell your doctor.
• Pregnancy and breastfeeding: Oral use is not recommended; discuss the product you apply to the skin with your doctor too.
• Oral aloe: Cramps, diarrhoea, low potassium and liver problems have been reported; it may interact with some heart and diabetes medications. It should not be confused with cosmetic use.