This is a summary of research papers and studies
from the National Center for Biotechnology Information (NCBI)

ABOUT SESAME SEED OIL

Shea nut oil, more commonly known in its solid form as shea butter, is a natural substance derived from the kernels of the African shea tree, Vitellaria paradoxa. Indigenous to the sub-Saharan African region, this botanical resource has held immense cultural, economic, and medicinal significance for centuries. In recent years, it has emerged as a pivotal core ingredient in the global cosmetic and pharmaceutical industries due to its multifaceted ability to nourish, protect, and heal the skin. 

Properties

The unique efficacy of shea nut oil is a direct result of its complex chemical makeup, which consists of two primary components: "soap-like" triglyceride component, and "non-soap-like" component. 

Fatty Acid Profile: Shea butter is composed of a balanced mix of saturated and unsaturated fatty acids. Analytical studies reveal five major fatty acids:

• Oleic acid (32–60%): A monounsaturated omega-9 fatty acid that contributes to the oil's liquid consistency and permeability.
• Stearic acid (28–55%): A saturated fatty acid that gives shea butter its solid texture and provides occlusive protection.
• Linoleic acid (4–8%): A polyunsaturated omega-6 fatty acid essential for maintaining the skin water permeability barrier.
• Palmitic acid (3.2–7.5%) and Arachidic acid (0.8–2%): Additional saturated fats that enhance the skin-conditioning properties.

Unlike many other plant oils, shea butter contains an exceptionally high percentage of unsaponifiables (non-soap-like components), typically ranging from 2% to 11% rich in bioactive compounds, including:

• Triterpenes: Such as α-amyrin, β-amyrin, and lupeol, which are primarily responsible for the oil's potent anti-inflammatory and wound-healing effects.
• Tocopherols (Vitamin E) and Phenols: These provide significant antioxidant activity, protecting the skin from oxidative stress and environmental damage.
• Phytosterols: Including stigmasterol and campesterol, which aid in skin barrier recovery.

Functions  

Shea nut oil serves several critical functions when applied to the skin, acting as a multipurpose therapeutic agent.

Emollient and Occlusive Function

Shea butter acts as an emollient by filling the gaps between skin barrier cells, which smooths the skin surface. Its occlusive nature allows it to form a protective film that traps moisture within the skin layers, effectively preventing transepidermal water loss (TEWL).

Permeation Enhancement

Shea butter is an effective drug carrier. It enhances the transdermal delivery of active ingredients by improving their penetration into the deeper layers of the skin.

Skin Barrier Augmentation

By interacting with the skin's natural lipid matrix, shea butter helps restore the "mortar" between the "bricks" of the skin barrier. It has been shown to support the levels of ceramides—essential lipids for barrier integrity—with studies detecting six specific ceramide subclasses in skin treated with shea butter.

Benefits for the Skin 

The integration of shea nut oil into skincare regimens offers a wide array of clinically documented benefits. 

Intensive Hydration and Barrier Repair

Scientific investigations demonstrate that topical application of shea butter can lead to a 37.8% reduction in TEWL and a 58% increase in skin hydration within 24 hours. This rapid improvement is attributed to the oil's ability to immediately integrate with skin lipids and restore the barrier function, making it superior to mineral oil in some contexts. 

Potent Anti-Inflammatory Effects

The triterpene esters (cinnamates and acetates) in shea butter inhibit inflammation by suppressing proinflammatory cytokines. Because of these properties, shea butter is highly effective in treating inflammatory conditions like Atopic Dermatitis (AD). Clinical trials have found that creams containing shea butter can be as effective as 1% hydrocortisone in reducing the severity of childhood eczema without the side effects of topical corticosteroids. 

Antioxidant and Anti-Aging Potential

Rich in vitamins A and E, shea butter acts as a scavenger for reactive oxygen species (ROS). It protects skin proteins from structural damage and inhibits the activity of proteases like elastase and collagenase, which break down the skin's connective tissue. This helps maintain skin elasticity and reduces the appearance of fine lines and wrinkles. Furthermore, its mild sun-screening effect provides a layer of photoprotection against UV-induced damage. 

Promotion of Wound Healing

The triterpenes in shea butter, particularly lupeol, stimulate the migration and proliferation of keratinocytes, which are essential for the closure of wounds. These compounds also enhance collagen synthesis and local blood circulation, accelerating the natural repair mechanisms of the skin barrier. 

Conclusion

Shea nut oil is more than a simple moisturizer; it is a bioactive complex that actively modulates skin physiology. Through its balanced fatty acid profile and high concentration of anti-inflammatory triterpenes, it provides a comprehensive solution for barrier repair, hydration, and protection against environmental stressors. Whether used as a primary treatment for Atopic Dermatitis or as a protective agent in anti-aging formulations, shea butter remains one of nature’s most effective ingredients for maintaining healthy, resilient skin.