If you've experienced skin irritation from aloe vera products, aloin might be the culprit. Here's what you need to know about this compound—and why quality aloe products remove it.
What is Aloin?
Aloin (also called barbaloin) is a yellow latex compound found between the outer leaf rind and inner gel of Aloe vera plants. It's part of the plant's natural defense system against herbivores and environmental stress.
Key Facts About Aloin
- Location: Latex layer between rind and inner gel
- Appearance: Yellow to brown liquid
- Chemical class: Anthraquinone glycoside
- Taste: Extremely bitter
- Primary effect: Laxative and potential skin irritant
Why Aloin Causes Problems
1. Skin Irritation
Aloin can cause contact dermatitis, especially in people with:
- Sensitive skin
- Eczema or atopic dermatitis
- Compromised skin barrier
- Existing inflammation
Symptoms may include redness, itching, burning sensation, or rash—exactly what you're trying to soothe with aloe in the first place.
2. Digestive Effects
When ingested, aloin acts as a stimulant laxative. While historically used for constipation, it can cause:
- Abdominal cramping
- Diarrhea
- Electrolyte imbalance (with chronic use)
- Dehydration
The FDA removed aloe latex from over-the-counter laxative products in 2002 due to lack of safety data.
3. Photosensitivity
Aloin may increase skin sensitivity to UV radiation, potentially worsening sunburn risk—counterproductive when using aloe for sun recovery.
4. Yellow Staining
Aloin's yellow-brown color can temporarily stain skin and permanently stain fabrics, making products with high aloin content cosmetically problematic.
How Aloin is Removed
Quality aloe vera products use several methods to minimize or eliminate aloin:
Method 1: Hand Filleting (Best)
The gold standard for aloin removal. Skilled processors:
- Hand-cut mature aloe leaves
- Remove the thick outer rind completely
- Separate and discard the yellow latex layer
- Extract only the clear inner gel
Result: Minimal aloin contamination from the start.
Method 2: Cold-Water Rinsing
After filleting, gel is rinsed with purified cold water to wash away any residual aloin. Multiple rinses reduce aloin to trace levels.
Method 3: Activated Charcoal Filtration
Aloe gel is passed through activated charcoal filters, which selectively bind and remove aloin while preserving polysaccharides and other beneficial compounds.
Effectiveness: Can reduce aloin to <0.1 ppm (parts per million).
Method 4: Whole-Leaf Processing (Avoid)
Some manufacturers grind the entire leaf—rind, latex, and gel—then filter. This method:
- Often leaves higher residual aloin
- May include unwanted plant compounds
- Requires aggressive filtering that can damage polysaccharides
We don't recommend products using whole-leaf processing unless they provide aloin test results showing <1 ppm.
Aloin Testing Standards
| Standard | Aloin Limit | Notes |
|---|---|---|
| IASC Certified | <10 ppm | International Aloe Science Council certification |
| FDA Recommendation | <1 ppm for topical | Recommended for cosmetic use |
| Aloe Team Standard | <0.1 ppm | 10x stricter than IASC, 10x stricter than FDA |
How to Identify Aloin-Free Products
Look for These Indicators:
✓ Positive Signs
- States "aloin-free" or "decolorized" on label
- IASC certified seal
- Mentions "inner leaf" or "filleted" processing
- Provides aloin test results or certificates
- Clear or slightly opaque gel (not yellow)
- Minimal to no bitter taste (if for oral use)
⚠ Red Flags
- Yellow or brown-tinted gel
- "Whole leaf" processing without decolorization
- No mention of aloin testing
- Very cheap price (may indicate low-quality processing)
- Bitter taste (indicates latex presence)
Does Aloin-Free Mean Less Effective?
No. This is a common misconception.
The beneficial compounds in aloe vera are polysaccharides (especially acemannan), glycoproteins, and enzymes—all found in the inner gel, not the latex layer.
| Compound | Location | Effect |
|---|---|---|
| Aloin | Latex layer | Irritant, laxative |
| Acemannan | Inner gel | Immunomodulatory, anti-inflammatory |
| Polysaccharides | Inner gel | Wound healing, moisturizing |
| Glycoproteins | Inner gel | Anti-inflammatory, skin soothing |
Removing aloin actually improves product safety and tolerability without sacrificing efficacy.
Special Considerations
For Sensitive Skin
If you have reactive or sensitive skin, aloin-free aloe is essential. Even trace amounts of aloin can trigger irritation in compromised skin barriers.
Recommendation: Look for products with <1 ppm aloin and perform a patch test on your inner arm before facial or full-body use.
For Sunburn Care
Sunburned skin is already inflamed and vulnerable. Aloin's potential photosensitizing effect makes aloin-free aloe the only safe choice for post-sun application.
For Oral Consumption
If you're drinking aloe vera juice, aloin content is critical. High-aloin products can cause digestive distress.
Safe limit for oral use: <10 ppm (IASC standard for drinkable aloe)
The Bottom Line
Aloin is a natural but problematic compound in aloe vera. It causes skin irritation, digestive issues, and doesn't contribute to aloe's beneficial effects.
Quality aloe products remove aloin through careful processing while preserving the polysaccharides and glycoproteins that make aloe effective.
When shopping for aloe:
- Look for "aloin-free" or "decolorized" labeling
- Check for IASC certification or aloin test results
- Avoid products that don't mention aloin at all
- Choose inner-leaf or filleted processing over whole-leaf
Scientific References
- Boudreau MD, Beland FA. (2006). An evaluation of the biological and toxicological properties of Aloe barbadensis (miller), Aloe vera. J Environ Sci Health C Environ Carcinog Ecotoxicol Rev, 24(1):103-54.
- Chokboribal J, et al. (2015). Decolorization of Aloe vera gel by activated charcoal: effects on bioactivity. J Appl Pharm Sci, 5(6):56-59.
- Guo X, Mei N. (2016). Aloe vera: A review of toxicity and adverse clinical effects. J Environ Sci Health C, 34(2):77-96.
- International Aloe Science Council. (2021). IASC Certification Program Standards.
- Sahu PK, et al. (2013). Therapeutic and Medicinal Uses of Aloe vera: A Review. Pharmacol Pharm, 4:599-610.