IngredientsGlyceryl dilaurate (CAS No. 27638-00-2) is the diester of glycerin and lauric acid. It is known by a range of synonyms including dilaurin, glycerol dilaurate, glycerine dilaurate, didodecanoyl glyceride, dilauroyl glyceride, and trade names such as Lexemul GDL and Emulsynt GDL. The compound is comprised of a mixture of C12:0 diglyceride racemates with acyl groups attached at either α,α- or α,β-positions.
As a diglyceride (diacylglycerol, DAG), it consists of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages, with two possible structural forms: 1,2-diacylglycerols and 1,3-diacylglycerols. The molecular formula is C₂₇H₅₂O₅. It is an ester derived from glycerol and lauric acid, a medium-chain fatty acid.
Glyceryl dilaurate is typically a white to off-white solid or semi-solid at room temperature and is soluble in oils but has limited solubility in water. Its molecular structure features two lauric acid chains esterified to a glycerol backbone, which contributes to its ability to stabilize emulsions and enhance the texture of formulations. It is characterized by its emulsifying and surfactant properties, making it useful in various applications, particularly in the cosmetic and food industries.
Lauric acid, systematically called dodecanoic acid, is a saturated fatty acid with a 12-carbon atom chain, thus having many properties of medium-chain fatty acids. Lauric acid, as a component of triglycerides, comprises about half of the fatty-acid content in coconut milk, coconut oil, laurel oil, and palm kernel oil. Glyceryl dilaurate is formed when two molecules of lauric acid are esterified to glycerol, and it therefore shares a direct biochemical lineage with these lauric-acid-rich natural fats and oils.
Diglycerides are natural components of food fats, though minor in comparison to triglycerides; they can act as surfactants and are commonly used as emulsifiers in processed foods. All cooking oils naturally contain small quantities of DAG, ranging from 0.8% in canola oil, 5.5% in olive oil, to 9.5% in cottonseed oil. Diglycerides are a minor component of many seed oils and are normally present at approximately 1–6%; or in the case of cottonseed oil as much as 10%.
Because the fatty acid component of glyceryl dilaurate is lauric acid, the primary natural botanical sources of the relevant precursor material are lauric-acid-rich oils. The primary fatty acid of coconut oil is lauric acid, which is present at approximately 45–53%; the metabolic and physiological properties of lauric acid account for many of the properties of coconut oil. Oils with high levels of lauric acid are known as lauric oils; otherwise, it is relatively uncommon. Lauric acid is also found in human breast milk (6.2% of total fat), cow's milk (2.9%), and goat's milk (3.1%).
Additionally, the palm tree Attalea speciosa, known in Brazil as babassu, provides approximately 50% lauric acid in babassu oil; Astrocaryum murumuru, a palm native to the Amazon, provides approximately 47.5% in "murumuru butter." Glyceryl dilaurate has been detected in pharmaceutical excipients derived from these sources.
Commercial production of DAG oil results from the enzymatic esterification of fatty acids from natural edible plant oils. Industrial production is primarily achieved by a glycerolysis reaction between triglycerides and glycerol. Commercially produced vegetable-derived DAG oil contains greater than 80% DAG, less than 20% TAG, less than 5% monoacylglycerols, and small amounts of emulsifiers and antioxidants to maintain quality.
Mono- and diglycerides are consumed every day in any normal mixed diet and they are also formed from triglycerides during the digestion and absorption of every meal containing fat. As such, diglycerides including the dilaurate form have been present in the human diet throughout history as incidental components of fat metabolism and as naturally occurring minor lipid fractions in seed oils and animal fats. There is no documented tradition-specific use of glyceryl dilaurate as an isolated compound in historical pharmacopeias or folk medicine, reflecting its status as a minor, naturally occurring component of food rather than a deliberately extracted medicinal agent.
Coconut oil and palm kernel oil—the primary botanical sources of lauric acid from which glyceryl dilaurate is derived—do have long traditional use histories in the cuisines and healing practices of tropical Southeast Asia, the Pacific Islands, and West Africa. Coconut oil is rapidly metabolized because it is easily absorbed and lauric acid is easily transported; the majority of ingested lauric acid is transported directly to the liver where it is directly converted to energy and other metabolites rather than being stored as fat. However, this traditional use was directed at the whole oil and not at glyceryl dilaurate as an isolated fraction.
Diglycerides, generally in a mix with monoglycerides (E471), are common food additives largely used as emulsifiers. They are often included in bakery products, beverages, ice cream, peanut butter, chewing gum, shortening, whipped toppings, margarine, confections, and some snack products. The use of mixed mono- and diglycerides as commercial emulsifiers dates to the mid-twentieth century; specific exploitation of glyceryl dilaurate as an isolated ingredient emerged primarily in the cosmetics and pharmaceutical industries of the late twentieth century.
A diglyceride (diacylglycerol) consists of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages; two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. The CIR Expert Panel noted that depending on the chain length and structure, the 1,3-diglycerides might contain some 1,2-diglycerides. This distinction is toxicologically significant, as discussed in the Safety section below.
The molecular structure of glyceryl dilaurate — two lauric acid chains esterified to a glycerol backbone — contributes to its ability to stabilize emulsions and enhance the texture of formulations. Like all glyceryl diesters, it possesses an amphiphilic character: the glycerol head group provides a degree of hydrophilicity, while the two lauroyl chains provide hydrophobicity. Glyceryl dilaurate and the other glyceryl diesters are classified as diacylglycerols (also known as diglycerides or glyceryl diesters) that function as skin conditioning agents and emollients in cosmetics.
In biochemical signaling, diacylglycerol functions as a second messenger signaling lipid, and is a product of the hydrolysis of the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) by the enzyme phospholipase C (PLC) — a membrane-bound enzyme — that, through the same reaction, also produces inositol trisphosphate (IP3). This endogenous role of diacylglycerols in cellular signaling is relevant to the pharmacological and toxicological profile of glyceryl dilaurate and related compounds, particularly their potential interactions with protein kinase C (PKC). PKC is a serine-threonine kinase which also requires calcium ion for its activation; activated PKC phosphorylates proteins of the cellular signal cascade, which eventually induce expression of growth regulatory genes, which in turn may promote the growth of tumours.
Triglyceride digestion begins in the intestinal tract; initially, the triglyceride is hydrolyzed enzymatically to α,β-diglyceride, which is then hydrolyzed to β-monoglyceride in the lumen of the intestines; these hydrolytic reactions occur at an oil-water interface; approximately 28% of the β-monoglyceride is isomerized to α-monoglyceride, and approximately 75% of the α-monoglyceride is further hydrolyzed to free glycerol. Pancreatic lipase enzymes selectively hydrolyze and remove the fatty acids at the sn-1 and sn-3 positions while leaving the sn-2 fatty acid attached to the glycerol backbone to generate a sn-2 monoglyceride, which can be absorbed into the intestinal cells and reformed as a triglyceride or phospholipids for transport in the bloodstream.
Detailed studies have shown that the majority of ingested lauric acid is transported directly to the liver where it is directly converted to energy and other metabolites rather than being stored as fat; such metabolites include ketone bodies, which can be used by extrahepatic tissues, such as the brain and heart, as an immediate form of energy.
One of the most pharmacologically documented mechanisms of action for glyceryl dilaurate is its ability to increase the permeability of the stratum corneum to co-administered compounds. Aungst et al. (1986) evaluated the effect of glyceryl dilaurate or glyceryl laurate on the penetration of naloxone HCl (a potent opioid antagonist used for the reversal of narcosis) across cadaver skin using Franz diffusion cells; glyceryl dilaurate was evaluated at a concentration of 10% in propylene glycol; the average flux through human cadaver skin (10 experiments) for naloxone alone was 1.6 ± 0.4 μg/cm²·h⁻¹; in the presence of glyceryl dilaurate, average naloxone flux increased to 18.7 ± 1.8 μg/cm²·h⁻¹ (3 experiments). This represents an approximately 12-fold enhancement of transdermal drug flux, representing one of the more potent penetration-enhancing effects observed among glyceryl esters in that study.
The most documented area of scientific investigation for glyceryl dilaurate is its role as a pharmaceutical penetration enhancer in topical and transdermal formulations. The Franz diffusion cell data described above — demonstrating an approximately 12-fold increase in naloxone flux across cadaver skin — provides in-vitro human tissue evidence for this mechanism. A patent-described composition for enhancing the penetration of a drug substance across the stratum corneum and into deeper skin layers uses an emulsifier comprising glycerol dilaurate and polyoxyethylene-10 stearyl ether in a weight ratio from about 5:95 to about 75:25, in combination with an oil and water, at a glycerol dilaurate concentration from about 0.1 to about 20 weight %. The evidence for glyceryl dilaurate as a penetration enhancer is based primarily on in-vitro studies using ex-vivo human cadaver skin and patent disclosures; there are no controlled clinical trials in living human subjects specifically evaluating glyceryl dilaurate's penetration-enhancing efficacy as a primary endpoint.
A histological evaluation was performed on human skin from female volunteers (18 to 56 years old) who had applied a prototype lotion or placebo formulation, both containing 0.5% glyceryl dilaurate, consecutively for 16 weeks or 21 weeks; skin irritation was not observed in any of the subjects tested; biopsies (2 mm) taken from both legs of five subjects indicated no recognizable abnormalities of the skin; the epidermis was normal in thickness, and there was no evidence of scaling, inflammation, or neoplasms in any of the tissues that were evaluated. This small repeated-use study (limited sample size of five subjects for biopsy evaluation) provides limited but affirmative human evidence for skin tolerability. It does not constitute a clinical efficacy study for emollient function.
Glyceryl dilaurate's antimicrobial activity has been examined in the context of its relationship to glyceryl monolaurate (monolaurin), which bears a well-established literature. Kabara et al. (1977) observed that glyceryl dilaurate had no effect on the antimicrobial activity of glyceryl laurate in the bacterial strain Streptococcus pyogenes; in this assay, bacterial cultures were treated with 5 μg/ml glyceryl laurate + 5 μg/ml glyceryl dilaurate, 10 μg/ml glyceryl laurate + 10 μg/ml glyceryl dilaurate, 5 μg/ml glyceryl laurate, and 10 μg/ml glyceryl dilaurate, respectively, with bacterial growth monitored by changes in optical density. This finding is important: it indicates that glyceryl dilaurate does not share the intrinsic antimicrobial properties associated with glyceryl monolaurate against this organism. Lauric acid and monolaurin have demonstrably significant antimicrobial activity against gram-positive bacteria and a number of fungi and viruses — properties that are not attributed to the dilaurate form in the available literature.
DAG-enriched oil (particularly 1,3-DAG) has been investigated extensively as a fat substitute due to its ability to suppress the accumulation of body fat, with total annual sales of approximately US$200 million in Japan since its introduction in the late 1990s till 2009. In 1998 the Japanese Ministry of Health, Labour and Welfare (MHLW) approved the use of DAG as a "food for specified health use," and in 2000 the US Food and Drug Administration (FDA) classified DAG as a food ingredient that is generally recognized as safe (GRAS). However, the body-composition and metabolic research on DAG oil is primarily based on mixed-chain diacylglycerol oils derived from soybean or canola fat, not on glyceryl dilaurate specifically. The evidence base for glyceryl dilaurate as an ingredient with specific metabolic or body-composition effects in humans is absent; the broader DAG oil literature should not be assumed to apply directly to this specific lauric acid-derived compound.
Diacylglycerols — as a class — are recognized endogenous activators of protein kinase C. The scientific literature reviewed in the CIR safety assessment discusses 1,2-diacylglycerols in the context of PKC signaling. The CIR Panel noted that nominally 1,3-diglycerides contain 1,2-diglycerides, raising the concern that 1,2-diglycerides could potentially induce hyperplasia; data regarding the induction of PKC and the tumor promotion potential of 1,2-diacylglycerols increased the level of concern; however, most of the diglycerides considered in this safety assessment have fatty acid chains longer than 14 carbons and none have mixed saturated/unsaturated fatty acid moieties. Lauric acid is a 12-carbon fatty acid, making glyceryl dilaurate specifically relevant to this discussion. Nevertheless, the CIR Panel considered it particularly important that a 21-week use study of a prototype lotion containing 0.5% glyceryl dilaurate (a 14-carbon chain fatty acid — [note: actually 12-carbon]) indicated no evidence of scaling, inflammation, or neoplasms in biopsy specimens.
Glyceryl dilaurate does not have a defined therapeutic dosage as a standalone dietary supplement or drug substance. The following concentrations are sourced from specific studies and regulatory submissions:
No standardized human oral dosing regimen for glyceryl dilaurate as an isolated dietary supplement has been established or published in peer-reviewed clinical trials.
In 1998 the Japanese Ministry of Health, Labour and Welfare (MHLW) approved the use of DAG as a "food for specified health use," and in 2000 the US FDA classified DAG as a food ingredient that is generally recognized as safe (GRAS). The affirmation of mono- and diglycerides as GRAS as a direct human food ingredient at 21 CFR 184.1505 covers their use as dough strengtheners, emulsifiers, flavoring agent adjuvants, formulation aids, lubricants and release agents, solvents and vehicles, stabilizers and thickeners, surface-active agents, surface-finishing agents, and texturizers. Mono- and diglycerides of fatty acids (E471) are listed in Commission Regulation (EU) No 231/2012 as an authorised food additive, categorized in "Additives other than colours and sweeteners."
According to the Ministry of Health, Labor and Welfare (MHLW), glyceryl diesters reviewed in the CIR report are not included on the list of ingredients that must not be combined in cosmetic products or on the list of restricted ingredients for cosmetic products that are marketed in Japan.
The CIR Expert Panel concluded that the available safety test data indicate that diglycerides in the 1,3-diester form do not present any significant acute toxicity risk, nor are these ingredients irritating, sensitizing, or photosensitizing.
Reviews assessing the safety of DAG oil found that clinical studies indicated that DAG oil is well tolerated, with no significant toxicity effects noted.
Glyceryl dilaurate was a mild primary irritant in albino rabbits, but not a skin sensitizer in guinea pig maximization tests. An eye shadow containing 1.5% glyceryl dilaurate did not induce skin irritation in a single insult patch test, but mild skin irritation reactions to a foundation containing the same concentration were observed. The apparent difference in irritation potential between formulation types suggests that vehicle composition and other excipients may modulate the irritation potential.
The most specific and notable safety consideration for glyceryl dilaurate is the presence of 1,2-diglyceride isomers as contaminants in preparations nominally described as 1,3-diglycerides. The CIR Panel noted that these nominally 1,3-diglycerides contain 1,2-diglycerides, raising the concern that 1,2-diglycerides could potentially induce hyperplasia; data regarding the induction of PKC and the tumor promotion potential of 1,2-diacylglycerols increased the level of concern; most of the diglycerides considered in the safety assessment, however, have fatty acid chains longer than 14 carbons and none have mixed saturated/unsaturated fatty acid moieties.
Some 1,2-diglycerides, especially those with carbon chains less than 14 in length and mixed saturated/unsaturated fatty acids, may have a tumor promotion potential. Since lauric acid has a 12-carbon chain, falling below the 14-carbon threshold, glyceryl dilaurate is in a structurally relevant category. However, the activity of 1,2-diacylglycerols may be reduced when the fatty acid moiety in the structure is a long-chain fatty acid. Furthermore, the CIR Panel considered it important that a 21-week use study of a prototype lotion containing 0.5% glyceryl dilaurate (a 12-carbon chain fatty acid) indicated no evidence of scaling, inflammation, or neoplasms in biopsy specimens; DNA synthesis assays on glyceryl dilaurate and glyceryl distearate indicated that neither substance altered cell proliferation (as determined by DNA synthesis) in normal human dermal fibroblasts in vitro at doses up to 10 μg/ml.
The 1,3-diglyceride isomer is not a significant toxicant in acute, short-term, subchronic, or chronic animal tests. Diacylglycerol oil was not genotoxic in the Ames test, in mammalian Chinese hamster lung cells, or in a rodent bone marrow micronucleus assay.
Whereas no data are available regarding reproductive or developmental toxicity, there is no reason to suspect any such toxicity because the dermal absorption of these chemicals is negligible. This conclusion by the CIR Panel is specific to topical/cosmetic use and does not constitute a safety evaluation for oral ingestion at supplemental doses.
Mono- and diglycerides are consumed every day in any normal mixed diet and they are also formed from triglycerides during the digestion and absorption of every meal containing fat; no harmful effects have been specifically associated with mono- or diglycerides.
A mixture of lauric acid glycerides (40% monolaurin, 45% dilaurin, 15% trilaurin) was fed to rats over a two-year period at a concentration of 25% of the diet of a nutritionally adequate laboratory chow; there was no histopathological evidence of toxicity attributable to the lauric glycerides (Fitzhugh et al., 1960). This is the longest-duration and highest-dose animal toxicology data available for a lauric glyceride mixture containing glyceryl dilaurate as a substantial component.
Glyceryl dilaurate has a limited and primarily applied-science evidence base. Its best-documented roles are as a cosmetic emulsifier, skin conditioner, and pharmaceutical penetration enhancer, supported by in-vitro ex-vivo human skin studies, small human tolerability studies, and regulatory review. The compound has no peer-reviewed randomized controlled clinical trials evaluating efficacy for any health outcome in humans. Its dietary supplement applications (as described in one 2016 patent application related to glyceryl laurates and muscle growth) remain at the level of patent claims without published clinical evidence. The antimicrobial literature demonstrates that, unlike its monoester relative glyceryl monolaurate, glyceryl dilaurate does not exhibit inherent antimicrobial activity against at least one gram-positive bacterium tested. The long-term animal dietary data, based on a lauric glyceride mixture rather than pure glyceryl dilaurate, provides reassurance for the class but is not directly transferable to high-dose isolated supplemental use in humans.
Health conditions that Glyceryl dilaurate may help support.
Body systems that Glyceryl dilaurate may help support.
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