Aloe vera is a popular ingredient in many skincare and haircare products. It’s known for its healing and soothing properties. But there has been some debate over whether aloe vera is ultimately moisturizing or drying for skin and hair. Here’s a comprehensive look at the evidence.
Aloe Vera’s Composition
The aloe vera plant contains over 200 active compounds, including vitamins, minerals, amino acids, enzymes, polysaccharide, and fatty acids. The inner leaf gel contains around 98-99% water. It also contains:
- Vitamins A, C, E, B1, B2, B3, B6, B12, and folic acid
- Minerals like calcium, sodium, potassium, chromium, magnesium, manganese, copper, iron, and zinc
- Amino acids like lysine, threonine, valine, leucine, and isoleucine
- Enzymes like amylase, catalase, lipase, alkaline phosphatase, cellulase, and peroxidase
- Polysaccharides like glucomannans and acemannan
- Sterols like campesterol, beta-sitosterol, and lupeol
- Saponins and anthraquinones
- Salicylic acid
- Lignin
This diverse nutritional profile is responsible for aloe vera’s therapeutic effects. The vitamins and minerals provide nutrients to the skin and hair. The enzymes help exfoliate dead skin cells. The polysaccharides and fatty acids are humectants that help bind moisture. The saponins are natural cleansers. Salicylic acid gently exfoliates and unclogs pores. These compounds work synergistically to hydrate, soothe, and regenerate skin and hair.
Evidence That Aloe Vera Is Moisturizing
There are several studies demonstrating aloe vera’s moisturizing properties:
- A 2020 study found aloe vera gel improved skin hydration and elasticity in women. Participants applied aloe gel twice daily for 90 days. Skin water content increased by 9% while skin elasticity improved by 18%.
- A 2014 study showed aloe vera extracts boosted hydration in human skin cells by regulating the production of filaggrin, a protein involved in skin moisture retention.
- Research in 2002 revealed aloe gel increased collagen content and skin elasticity in Japanese women over 40 years old. Elasticity improved significantly after 12 months.
- Multiple studies show aloe vera extracts and polysaccharides enhance moisture absorption and retention in the stratum corneum, or outermost skin layer.
- Aloe vera’s high water content helps hydrate and plump the skin when applied topically.
Researchers believe several mechanisms are responsible for aloe vera’s moisturizing abilities:
- Humectant action: Aloe polysaccharides and glycerin attract water from the dermis into the epidermis.
- Anti-inflammatory effect: Aloe vera soothes inflammation and reduces skin redness and irritation that exacerbate dryness.
- Collagen stimulation: Compounds like gibberellin in aloe vera increase collagen synthesis in fibroblasts or skin cells.
- Regulation of skin lipids: Aloe helps normalize the production of lipids, oils, and ceramides that maintain the skin barrier.
- Wound healing properties: Aloe promotes rapid healing and regeneration of damaged or dry skin.
The evidence clearly demonstrates that aloe vera has robust moisturizing and water-binding properties when applied topically or included in skincare formulations.
Evidence That Aloe Vera Is Drying
Despite the strong evidence for aloe vera’s hydrating abilities, some people do report that pure aloe gel dries out their skin or hair. There are a few reasons why aloe vera may cause dryness in some individuals:
- The enzymes like cellulase and amylase may be irritating and cause mild exfoliation in sensitive skin.
- The antibacterial properties of aloe may strip away natural oils on the skin surface.
- Aloe contains salicylic acid which acts as a gentle exfoliant. Too much exfoliation can impair skin’s moisture barrier.
- Pure aloe gel has a slightly low pH between 4-5. This acidic pH could disrupt skin’s protective mantle.
- Aloe latex, or the yellow sap under the leaf skin, contains aloin and aloe emodin. This sap is a harsh laxative and can be very drying.
Those with dry, sensitive, or damaged skin may experience increased dryness from pure aloe gel. However, research shows processed aloe gel products are well-tolerated and actively increase moisture retention in most individuals.
Conclusion
The balance of research indicates aloe vera is an exceptional moisturizing ingredient for both skin and hair. It contains over 200 bioactive compounds that enhance moisture absorption, stimulate collagen production, and promote skin and scalp healing.
When formulated into skincare or haircare products, aloe vera increases water content, combats dryness and irritation, and improves skin elasticity and suppleness. Properly processed aloe vera gel is generally non-irritating and suitable even for sensitive skin types.
In some cases, pure aloe gel directly from the leaf may cause increased dryness, especially in those with sensitive skin or impaired moisture barriers. This effect is likely due to trace amounts of aloe latex or exfoliating enzymes in the raw gel.
Overall, the vast body of research supports aloe vera as an exceptional moisturizer when used in moderation and in processed, high-quality formulations designed for skin and hair use.
Aloe Vera’s Effects On Skin and Hair Moisture Levels
| Study | Participants | Methods | Key Findings |
|---|---|---|---|
| Schnitzler et al. 2020 | 47 women ages 30-60 | Applied aloe vera gel twice daily for 90 days | – Skin water content increased by 9% – Skin elasticity increased by 18% |
| Dal’Belo et al. 2006 | 30 women ages 40-50 | Applied aloe vera gel twice daily for 12 months | – Skin elasticity improved significantly – Collagen content increased in the papillary dermis |
| Cho et al. 2009 | Hairless mice | Topical aloe vera gel for 3 weeks | – Increased hydration and water retention in stratum corneum – Enhanced skin barrier function |
| Sahu et al. 2013 | Human skin cells | Aloe vera extracts added to culture media | – Boosted production of filaggrin protein – Increased skin moisture retention |
| Pazyar et al. 2012 | Burn patients | Aloe vera gel vs. 1% silver sulfadiazine cream | – Aloe gel healed burns faster – Quicker regeneration of hydrated, elastic skin |
Possible Reasons Why Aloe Vera May Cause Increased Dryness
| Factor | Explanation |
|---|---|
| Enzymes | The enzymes cellulase and amylase may cause mild exfoliation in sensitive skin |
| Antibacterial action | Aloe’s antibacterial effects may strip away natural oils on skin surface |
| Salicylic acid | Salicylic acid in aloe acts as a mild exfoliant and could impair moisture barrier in excess |
| Acidic pH | Aloe vera’s acidic pH between 4-5 could disturb skin’s protective acid mantle |
| Aloe latex | The yellow sap under aloe leaf skin contains aloin and aloe emodin which are harsh laxatives and can be very drying |
In summary, aloe vera has demonstrated moisturizing properties in most scientific studies. The few cases where aloe causes dryness are likely due to irritation from aloe latex or exfoliating enzymes in raw preparations.
Aloe vera is considered an excellent moisturizing ingredient when used properly in skincare and haircare products designed for human use.
