Botanical oils are complex mixtures of triacylglycerols (fatty acid esters of glycerol) with some minor components such as tocopherols, phytosterols, and polyphenols that are either cold-pressed (virgin oils), solvent extracted, or super critical extracted. Saturated fatty acids present in botanical oils do not contain double bonds.

Caprylic Acid 8:0 and Capric Acid 10:0

These saturated fatty acids are present in coconut oil and palm kernel oil. Large quantities of these fatty acids are only found in seed oils of several species of the genus Cuphea, while capric acid also dominates the fatty acid profile of elm Ulmus americana L. seed oil. Known for their antimicrobial properties, both molecules play predominantly formulation roles in cosmetic applications by decreasing the melting point, lowering viscosity, providing efficient solvent, oxidative resistance, emollient, and conditioning properties to skin products.

Lauric Acid 12:0 and Myristic Acid 14:0

Lauric acid 12:0 is a major fatty acid present in coconut, palm, laurel, babassu, murumuru, and ucuhuba oil and butter. Lauric acid 12:0 reacted with sodium hydroxide produces laurate salts that form the basis for soap production. Among these plant oils, laurel fruit oil is unique due to its low saturation ratio (42–45%) compared to the other oils in this group (80–90%).

Additionally, nutmeg, and ucuhuba butters have a unique saturated fatty acid profile that is dominated by myristic acid 14:0. Both lauric acid 12:0 and myristic acid 14:0 showed a moderate degree of bacteriostatic properties, with the former one being also bactericidal at the MBC range of 7–375 μg/ml. Lauric acid 12:0 is also reaching the skin surface naturally as a part of the outward sebum flow that is dominated by the palmitoleic acid 16:1(n-7) isoforms, and exerts moderate inhibitory effects on the growth of skin bacteria associated with inflammatory acne at the minimal inhibitory concentration (MIC) range of 1–4 μg/ml.

Among these plant oils, only coconut and palm kernel oils have been studied clinically for skin care, especially that of neonates. Even though these oils were noted as good emollients that prevent transdermal water loss and increase skin moisture, controversy subsists about other beneficial effects associated with their use. As topically applied botanical oils penetrate largely only into the upper layers of the epidermis, their application occludes the skin surface and leads to break outs on most skin types, other than very dry skin, due to their high comedogenic properties.

Palmitic Acid 16:0 and Stearic Acid 18:0

Among botanical oils, palm pulp oil, sea buckthorn fruit oil, and cocoa bean oil contain naturally high amounts of palmitic acid 16:0. Cocoa beans oil also contains high levels of stearic acid 18:0, similar to kokum, sal, mango, and shea butters that is responsible for their semisolid appearance and consistency.

In human sebaceous glands, exogenously supplied palmitic acid 16:0 is desaturated at an unusual C6 position to produce sapienic acid 16:1(n-10), and both molecules can undergo elongation to stearic acid 18:0 and sebaleic acid 18:2(n-10), respectively. Both palmitic acid 16:0 and stearic acid 18:0 are preferred over palmitoleic acid 16:1(n-7) and oleic acid 18:1(n-9) for incorporation into wax esters, while linoleic acid 18:2(n-6) is the only fatty acid metabolized into two carbon precursors via β-oxidation in the skin. The excess of palmitic acid 16:0 inhibits metabolism of linoleic acid 18:2(n-6) and α-linolenic acid 18:3(n-3) into the respective elongation products dihomo-γ-linolenic acid 20:3(n-6) and eicosatetraenoic acid 20:4(n-3), with the former one being a direct precursor of anti-inflammatory eicosanoids.

Arachidic Acid 20:0, Behenic Acid 22:0, and Lignoceric Acid 24:0

Long chain saturated fatty acids with carbon chain length over C20 are present in skin in small quantities. In plants, moderate amounts of arachidic acid 20:0 can be found in rambutan, cupuacu, and peanut oils. Likewise, behenic acid 22:0 can be found in ben (moringa) and peanut oils, while lignoceric acid 24:0, a byproduct of plant lignin biosynthesis, can be found in wood tar and in minor quantities in peanut oil. Despite their low bioavailability, these fatty acids are cholesterol-raising agents in humans, and therefore are used in topical skin and hair applications mostly for their lubricant and moisturizing properties.