Aloe Vera, Decoded: Inner Leaf, Whole Leaf, 1x, 200x and Aloin

From Mexican fields to Indian gardens to Mediterranean windowsills, aloe vera is one of the most widely grown and loved skincare plants in the world. It's also one of the most confusing to buy as an ingredient: inner leaf, whole leaf, decolourised, 1x, 10x, 200x... Let's decode it.

Anatomy of an aloe leaf

An aloe leaf has three parts:

• The rind: the green outer skin.
• The latex: a thin yellow layer just under the rind. It contains aloin and related compounds, which are strongly laxative.
• The inner leaf gel: the clear, slippery centre that skincare is after.

The EU medicines regulator notes that the colourless gel comes from different cells than the yellow juice, and that the yellow juice carries the laxative anthranoids (EMA assessment report).

Inner leaf vs whole leaf

The International Aloe Science Council, the industry's standards body, defines inner leaf material as having the rind and latex removed, while whole leaf material grinds up the entire leaf. Whole leaf can then be decolourised by filtering through activated carbon, which removes most of the aloin (IASC position statement).

Why aloin matters

• The US Cosmetic Ingredient Review recommends that anthraquinone levels in cosmetic aloe ingredients stay at 50 ppm or below (CIR, 2007).
• California added non-decolourised whole-leaf aloe extract to its Proposition 65 list after IARC classed it as "possibly carcinogenic" (based on studies of drinking it). Decolourised extract and inner gel aren't covered (California OEHHA).

For formulators: choose inner leaf or decolourised grades, and ask suppliers for aloin data on the Certificate of Analysis.

What "1x" and "200x" mean

These numbers describe concentration relative to single-strength aloe juice, the juice as it comes from the leaf. The IASC quality standard uses this "Nx" convention, for example noting that a 10x concentrate should have about ten times the solids of single-strength juice (IASC Aloe Vera Quality Standard).

• Aloe Vera Juice, 1x: ready to use, equivalent to single-strength juice.
• Aloe Vera Powder, 200x: concentrated about 200-fold.

The handy maths: 1 part of 200x powder in 199 parts water gives roughly single-strength juice. So about 0.5% of 200x powder in your water phase is roughly the same as using 100% 1x juice. That's why powder is popular: it's light to ship, stores well and lets you choose your strength. Check your supplier's sheet, as grades vary (see the dictionary entry).

Does aloe actually work?

Aloe's reputation for soothing burns has some support. A systematic review of four trials (371 patients) found burns healed about 8.8 days faster with aloe, though the authors said the evidence was too inconsistent for firm conclusions (Maenthaisong et al., Burns, 2007). In cosmetics, it's best positioned as a soothing, hydrating base ingredient. Keep medical claims out.

Formulating with aloe

• Use aloe juice as part, or even all, of your water phase in after-sun gels, toners and light lotions.
• Aloe is a microbe magnet (sugars and polysaccharides), so it always needs a robust preservative.
• Pair it with Panthenol, Allantoin or Cucumber Hydrosol for a cooling after-sun.
• Curious about the next generation? Try Aloe-Derived Extracellular Vesicles (see our novel ingredients post), or Aloesin for tone-evening formulas.

Explore Soothing & Redness and Botanical Extracts.