What Is Myristic Acid? Sources, Health, and Uses

Myristic acid is a 14-carbon saturated fatty acid found naturally in coconut oil, palm kernel oil, dairy fat, and nutmeg butter. It plays a surprisingly wide range of roles in the body, from anchoring proteins to cell membranes to influencing cholesterol levels, and it shows up in products as varied as infant formula, skin creams, and food flavorings. Its health profile is more nuanced than the blanket “saturated fat is bad” message suggests, with controlled feeding studies showing it raises both LDL and HDL cholesterol and animal research pulling in opposite directions on blood sugar.

A Saturated Fat With a Distinctive Chain Length

Fatty acids are categorized by how long their carbon chain is and whether that chain contains any double bonds. Myristic acid has 14 carbons in a straight chain with no double bonds, making it a medium-to-long-chain saturated fatty acid. In scientific shorthand it is written as C14:0. That chain length matters because the body handles myristic acid differently from shorter-chain fats (like those in butter) and longer-chain ones (like palmitic acid, the 16-carbon saturated fat dominant in palm oil and meat). In rat liver cells, myristic acid was taken up more rapidly and oxidized at a much higher rate than palmitic acid, with roughly seven times more of the initial myristic acid going to oxidation products over four hours. The remaining myristic acid was largely elongated into palmitic acid, whereas palmitic acid itself tended to be packaged into stored fat molecules instead of being burned.

This metabolic quirk means myristic acid doesn’t linger in the same way that palmitic acid does. It is shuttled into energy production or converted to longer chains rather quickly. That distinction is worth keeping in mind when reading about its health effects, because lumping all saturated fats together misses real differences in how each one behaves once you eat it.

Where You Actually Encounter It

Myristic acid is widespread in the food supply, though it rarely dominates any single food the way oleic acid dominates olive oil. Coconut oil and palm kernel oil are the richest common dietary sources, with myristic acid making up a substantial share of their total fat. Dairy products, especially full-fat milk, cheese, and butter, contribute meaningful amounts as well. Nutmeg, the spice, is closely associated with myristic acid historically. The name itself comes from Myristica fragrans, the nutmeg tree, and myristic acid is one of the major compounds found in nutmeg oleoresins.

Beyond these concentrated sources, smaller amounts appear in beef tallow, fish oils, and various tropical nuts. In the food industry, myristic acid is also used as a flavor ingredient. A safety assessment noted that it is found widely distributed in fats throughout the plant and animal kingdom and has a low order of acute oral toxicity in rodents.

Human breast milk also contains myristic acid. A Norwegian birth cohort study tracked the fatty acid composition of breast milk and found that myristic acid levels varied among mothers, influenced partly by maternal diet.

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Cholesterol Effects Are Real but Not One-Dimensional

If there is one thing people have heard about myristic acid, it’s that it raises cholesterol. That’s true, but the full picture is more interesting than the headline. Controlled feeding trials in humans consistently show that myristic acid pushes up total cholesterol more potently than palmitic acid, the other major dietary saturated fat. In one carefully controlled study in healthy men and women, participants eating a diet enriched with myristic acid had mean serum cholesterol of about 5.19 mmol/L, compared with 4.96 mmol/L on a palmitic acid diet and 4.53 mmol/L on a high-oleic acid (monounsaturated) diet.

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A separate trial comparing a lauric-plus-myristic acid diet against a palmitic acid diet found that the lauric-myristic combination produced about 9% higher serum cholesterol, driven mainly by an 11% increase in LDL cholesterol.

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But myristic acid doesn’t just raise the “bad” LDL cholesterol. It also bumps up HDL cholesterol, the type associated with cardiovascular protection. In the same study comparing myristic to palmitic acid, myristic acid raised HDL cholesterol by 0.12 mmol/L relative to palmitic acid, and raised HDL by 0.15 mmol/L relative to oleic acid.

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Another trial confirmed this pattern: compared with oleic acid, myristic acid raised HDL cholesterol by about 0.10 mmol/L. The researchers concluded that myristic acid is cholesterol-raising, though the effect was less dramatic than earlier predictions had suggested, and the increase spans both LDL and HDL.

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A review of dietary experiments from the same era summarized the state of the evidence this way: myristic acid raises total and LDL cholesterol slightly more than palmitic acid does, but it also causes higher levels of HDL cholesterol.

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In animal research, the pattern holds with even more dramatic numbers. Gerbils fed a myristic acid-rich saturated fat diet showed total cholesterol roughly three times higher than controls, with LDL cholesterol about five times higher, but the HDL2 fraction (the more protective form of HDL) jumped substantially as well.

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So the honest answer about myristic acid and heart health is that it does raise LDL in a dose-dependent way, which conventional cardiovascular guidelines would flag as a concern. But its simultaneous HDL-raising effect complicates the simple “bad for your heart” label. Whether the net impact is harmful depends on how much you consume and the rest of your diet and risk profile.

A Wrinkle From Population Data

The controlled feeding studies paint a fairly consistent picture, but observational evidence from real populations introduces a wrinkle. A study of a Mediterranean population found that circulating myristic acid levels actually correlated negatively with HDL cholesterol, the opposite of what the feeding trials showed. People with more myristic acid in their blood tended to have lower HDL. The researchers followed up with lab experiments on liver cells and found that myristic acid increased the binding and uptake of HDL particles by liver cells through a pathway involving surface molecules called heparan sulfate proteoglycans. In cells conditioned with myristic acid, HDL binding increased, and cholesterol ester uptake from HDL rose by about 32%.

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This suggests that in the real world, chronic exposure to myristic acid may speed up the clearance of HDL from the bloodstream, counteracting or even reversing the HDL-raising effect seen in short-term feeding studies. The science hasn’t fully reconciled these two findings yet, and it’s a good reminder that a few weeks of controlled feeding and decades of habitual eating can tell different stories. This is an area where the evidence is genuinely unsettled.

Blood Sugar and Insulin Sensitivity

The relationship between myristic acid and blood sugar is, if anything, even more confusing than the cholesterol story. Multiple animal studies exist, and they point in opposite directions depending on the model used.

In one study, a strain of mice genetically prone to type 2 diabetes received chronic oral myristic acid. Their glucose tolerance improved, with blood glucose levels during tolerance tests dropping by roughly a quarter compared with mice given either a vehicle or palmitic acid.

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But a different study using mice fed a high-fat diet and then supplemented with myristic acid found the opposite result. Those mice showed significantly higher fasting insulin, greater insulin resistance as measured by standard indices, and worse glucose tolerance compared to high-fat diet controls without the myristic acid supplement. The researchers attributed this to increased inflammation in fat tissue and higher levels of a hormone called resistin that promotes insulin resistance.

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These conflicting findings likely reflect the different metabolic starting points of the animals. Mice that are genetically diabetic and lean respond differently from mice that are obese from overfeeding. The context of the existing diet and the animal’s metabolic state may determine whether myristic acid acts as a help or a hindrance.

In humans, a recent placebo-controlled trial in adults with borderline high blood sugar tested different doses of myristic acid and found that fasting blood insulin levels were modestly higher in the medium-dose group compared with placebo.

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The bottom line on blood sugar is that there isn’t a bottom line yet. The direction of the effect seems to depend heavily on the metabolic context, and the human data is still thin.

Its Role Inside Cells

Beyond its effects as a dietary fat, myristic acid plays a fundamental biological role that has nothing to do with nutrition. Cells use myristic acid to chemically tag proteins in a process called N-myristoylation. This involves attaching a myristic acid molecule to the very beginning of certain proteins as they are being built, which anchors those proteins to cell membranes and influences how they function. This modification affects signal transduction, protein stability, and where proteins end up inside the cell.

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N-myristoylation is highly specific to myristic acid. The enzyme responsible for this process, N-myristoyltransferase, has a strong preference for the 14-carbon chain. It generally won’t use palmitic acid (16 carbons) or shorter fatty acids. This makes myristic acid functionally irreplaceable in this role. Hundreds of human proteins undergo myristoylation, including many involved in immune signaling, cell growth, and programmed cell death. This is why myristic acid can never be zero in the body, regardless of how little you eat. The body will make what it needs.

The process also has a regulatory function. Proteins can be switched “on” or “off” depending on whether their myristoyl tag is exposed or tucked away, a mechanism sometimes called the myristoyl switch. This gives cells a way to rapidly relocate certain proteins from the interior of the cell to the membrane surface and back.

Myristic Acid and Inflammation

One of the reasons saturated fats in general are linked to chronic disease is their potential to trigger inflammatory pathways. Palmitic acid, the 16-carbon saturated fat, has been shown to directly activate an immune receptor called TLR4 on human immune cells, triggering the release of inflammatory signals. Research has demonstrated that palmitic acid physically binds to TLR4 and stimulates dendritic cells to mature and release the pro-inflammatory molecule IL-1β.

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Whether myristic acid activates TLR4 to the same degree is less well established. The mouse study that found myristic acid worsened insulin resistance on a high-fat diet also found increased fat tissue inflammation, suggesting some inflammatory potential. But much of the existing inflammation research has focused on palmitic acid rather than myristic acid specifically. Given that the body rapidly metabolizes myristic acid and often converts it to palmitic acid, it’s plausible that some of myristic acid’s inflammatory effects are actually downstream effects of that conversion. The picture remains incomplete.

Breast Milk and Infant Growth

Myristic acid is a natural component of human breast milk, and its concentration varies from mother to mother. Researchers have looked at whether the fatty acid composition of breast milk predicts how fast babies grow. In a Norwegian birth cohort, higher levels of myristic acid and lauric acid in breast milk were inversely associated with infant growth and rapid growth.

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This doesn’t necessarily mean myristic acid slows infant growth in a harmful way. Rapid growth in infancy is itself a risk factor for later obesity, so a milk composition that moderates growth velocity isn’t automatically a problem. The association may also reflect maternal dietary patterns rather than a direct effect of myristic acid itself. Infant formula manufacturers do include myristic acid-containing fats (often from coconut or palm kernel oil) in their products, aiming to approximate the fatty acid profile of human milk.

Antimicrobial Properties

Myristic acid and its chemical derivatives show some antimicrobial activity, a property that has attracted interest in both food preservation and pharmaceutical research. Sugar-based esters of myristic acid (monosaccharide monomyristates) have been tested against bacteria and fungi. These compounds showed antibacterial activity against gram-positive bacteria, likely because hydroxyl groups on the sugar portion interact with and destabilize the bacterial cell wall. Against gram-negative bacteria, which have an additional outer membrane, the activity was weaker. In antifungal testing, all three myristic acid ester compounds showed significant activity against Candida albicans, a common yeast pathogen, potentially by interfering with the fungal membrane component ergosterol.

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These are laboratory findings, not clinical treatments. The antimicrobial activity of free fatty acids at the concentrations found in food is generally modest. But in formulated products where concentrations can be controlled, myristic acid derivatives have potential as preservatives or as components of antimicrobial coatings.

Isopropyl Myristate in Skin and Drug Delivery

If you’ve ever read the back of a moisturizer, sunscreen, or topical medication, there’s a good chance you’ve seen isopropyl myristate (IPM) on the label. IPM is an ester made from myristic acid and isopropyl alcohol. It’s widely used in cosmetics as an emollient (it makes skin feel smooth) and in pharmaceuticals as a penetration enhancer, a substance that helps drug molecules pass through the outer layer of skin.

How it works at a molecular level has been studied using advanced diffraction techniques. Researchers found that IPM incorporates itself into the lipid layers of the stratum corneum (the skin’s outermost barrier) and disrupts their orderly structure. It appears to extract certain skin lipids into a separate phase, perturbing the multilamellar lipid assembly that normally keeps the barrier intact.

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Additional research using model skin membranes confirmed that IPM supported the formation of specific lipid structures and changed the way skin barrier components organized themselves.

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Interestingly, at least one study found that IPM’s effect on drug delivery is not always straightforward. When researchers tested hydrocortisone permeation through human stratum corneum, they found that incorporating IPM actually led to more densely packed lipid bilayers in certain conditions and decreased the permeation rate of the drug compared with a simpler formulation.

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This means IPM’s penetration-enhancing ability depends on the specific formulation, the drug being delivered, and how the other ingredients interact with skin lipids. It’s not a universal penetration booster, and formulators have to test it in context. For consumers, the practical takeaway is that IPM in your moisturizer is there to improve texture and absorption, and it has a long safety record in cosmetic use. People with acne-prone skin sometimes find that IPM can clog pores, which is why some products marketed for sensitive or oily skin specifically exclude it.

The Nutmeg Connection and a Naming Quirk

Myristic acid gets its name from nutmeg (Myristica fragrans), where it was first isolated in the mid-1800s. This has caused occasional confusion, because nutmeg also contains a volatile compound called myristicin, which is a completely different molecule. Myristicin is an aromatic ether with mild psychoactive properties at high doses. Myristic acid is a plain saturated fatty acid with no psychoactive effects whatsoever. The two share a botanical origin and a Latin root, but their chemistry and biological effects have nothing in common. Nutmeg oleoresins contain both compounds alongside terpenes like sabinene and pinene, but you would never confuse their roles once you know what each one is.

This naming coincidence occasionally trips up people searching for information about either compound, especially in the context of nutmeg safety or nutmeg supplements. If you see claims about “myristic acid from nutmeg” being psychoactive or toxic, the writer has almost certainly confused it with myristicin. The fatty acid itself is a routine dietary component with no such properties, and as noted earlier, it has been assessed as having low acute toxicity.