Caprylic Acid: Benefits, Side Effects and Dosage

Caprylic acid, also known as octanoic acid, is a medium-chain fatty acid found naturally in coconut oil, palm kernel oil, and dairy products. Over recent years, it has gained attention for a variety of potential health benefits, especially as a supplement in the form of MCT (medium-chain triglyceride) oil. Researchers have explored its roles in fighting infections, modulating metabolism, supporting neurological health, and more. However, like any supplement, understanding its benefits, potential side effects, and appropriate dosage is crucial for safe and effective use. This article dives deep into the latest research, summarizing the evidence around caprylic acid to help you make informed decisions.

Benefits of Caprylic Acid

Caprylic acid has been studied for its wide-ranging potential—from supporting gut health and acting as an antimicrobial, to helping with seizure control and modulating inflammation. Let’s explore these benefits in detail.

Benefit	Description	Evidence Highlights	Sources
Antimicrobial	Reduces harmful bacteria, including mastitis and Campylobacter	Shown to significantly lower bacterial pathogens	1, 3, 6
Neurological	Demonstrates anticonvulsant effects, may support seizure control	Increases seizure thresholds in animal models	2, 8
Anti-inflammatory	Suppresses inflammation and may help reduce atherosclerosis	Lowers inflammatory markers, improves lipid profiles	4
Metabolic Effects	May aid fat metabolism, appetite regulation, and energy supply	Used in MCT oil for malabsorption, modulates ghrelin	5

Table 1: Summary of Caprylic Acid Benefits

Antimicrobial and Antibacterial Activity

One of the most prominent and well-documented benefits of caprylic acid is its potent antimicrobial effect. Research shows that caprylic acid can inactivate a variety of harmful bacteria, including those responsible for bovine mastitis—a major problem in the dairy industry. Studies demonstrated that caprylic acid and its derivative, monocaprylin, sharply reduced populations of key pathogens such as Streptococcus and Staphylococcus species, suggesting potential as an alternative or adjunct to antibiotics 1.

In poultry science, caprylic acid has shown promise in reducing Campylobacter jejuni, a leading cause of foodborne illness in humans. Supplementing chicken feed with caprylic acid significantly decreased bacterial colonization in the intestinal tract, lowering the risk of contamination in poultry products. Notably, doses as low as 0.35% to 0.7% caprylic acid were effective, without adverse effects on feed consumption or body weight at lower dosages 3, 6. However, when administered via water, results were inconsistent, underscoring the importance of delivery method 7.

Neurological and Anticonvulsant Effects

Beyond its antimicrobial properties, caprylic acid is of growing interest in neurology. As a main component of the MCT ketogenic diet, it has demonstrated acute anticonvulsant effects in animal models. Specifically, caprylic acid increased the threshold for certain types of induced seizures in mice, indicating a protective effect against convulsions 2. This effect is believed to be partly mediated by the adenosine system and enhanced by glucose restriction, which mimics the ketogenic metabolic state 8. Caprylic acid also appears to potentiate the effect of traditional antiepileptic drugs like valproate, which may enhance clinical outcomes for some patients 2.

Anti-inflammatory and Cardiovascular Support

Chronic inflammation is a driver of many diseases, including atherosclerosis. Recent research in animal models found that dietary caprylic acid can suppress inflammation by modulating key signaling pathways (TLR4/NF-κB), leading to reduced body fat, improved lipid profiles, and less atherosclerotic plaque formation 4. This suggests a role for caprylic acid in supporting cardiovascular health and potentially counteracting inflammatory diseases.

Metabolic and Physiological Functions

Caprylic acid’s unique metabolic characteristics make it a valuable energy source, especially for individuals with impaired fat absorption or certain metabolic disorders. MCT oil, rich in caprylic acid, has long been used in clinical nutrition for these purposes 5. Intriguingly, recent research hints at a more nuanced role: caprylic acid is essential for the acylation of ghrelin, a hormone that regulates appetite. This means it may influence hunger and energy regulation—though the balance between appetite stimulation and weight management remains complex and an active area of study 5.

Side Effects of Caprylic Acid

While caprylic acid is generally considered safe, especially when consumed as part of the diet, high doses or concentrated supplements may lead to side effects. Understanding these is important for anyone considering caprylic acid supplementation.

Side Effect	Description	Risk Factors or Notes	Sources
Gastrointestinal	Nausea, diarrhea, reduced feed intake at high doses	More likely at higher supplementation	6
Weight Changes	Reduced body weight at high doses in animal studies	Seen with high (≥1.05%) feed doses	6
Appetite Effects	Potential appetite stimulation via ghrelin modification	May increase hunger in some contexts	5
Motor Impairment	Impaired motor function at very high acute doses	High-dose animal studies	2, 8

Table 2: Overview of Caprylic Acid Side Effects

Gastrointestinal and Digestive Effects

The most commonly reported side effects of caprylic acid, especially when taken in higher doses, are gastrointestinal in nature. In poultry studies, higher supplementation (above 1.05% of feed) led to reduced feed intake and lower body weight, although feed conversion efficiency was not affected 6. While these findings are in animals, they suggest that excessive intake in humans could similarly cause digestive upset—such as nausea or diarrhea.

Weight and Metabolic Changes

Although medium-chain fatty acids like caprylic acid are sometimes promoted for weight loss, the reality is more nuanced. Research indicates that caprylic acid is involved in the acylation of ghrelin, the hormone that stimulates appetite 5. This could mean that in some individuals, especially with high intake, caprylic acid might increase hunger, potentially counteracting weight loss efforts. Conversely, very high doses in animal feed sometimes led to reduced body weight, likely due to decreased food consumption from digestive discomfort 6.

Neurological and Motor Effects

At very high doses in animal models, caprylic acid has caused temporary motor impairment, such as reduced coordination and muscle strength 2, 8. However, these effects were generally seen at doses much higher than those used in dietary supplements or clinical settings.

Other Considerations

For most people consuming caprylic acid as part of a normal diet or through moderate MCT oil supplementation, side effects are rare and mild. However, individuals with liver disease or specific metabolic disorders should consult a healthcare professional before use, as medium-chain fatty acids are metabolized differently than long-chain fats.

Dosage of Caprylic Acid

Determining the optimal dosage of caprylic acid depends on the intended use, delivery method, and individual tolerance. Scientific studies offer insights, but more research is needed for precise human recommendations.

Use Case	Effective Dosage Range	Notes on Administration	Sources
Antimicrobial	0.35–0.7% in animal feed	Used in poultry for 3–7 days	3, 6
Neurological	10–30 mmol/kg (animal models)	Acute anticonvulsant effect in mice	2, 8
Metabolic/Clinical	10–30 g/day (as MCT oil in humans)	Used in malabsorption, energy support	5
Water Delivery	0.175–0.7% (variable efficacy)	Less reliable than feed administration	7

Table 3: Caprylic Acid Dosage in Research and Practice

Antimicrobial Dosage in Animal Studies

In poultry research, caprylic acid was effective at reducing pathogenic bacteria when included at 0.35–0.7% of feed for several days prior to slaughter. Higher doses sometimes led to reduced feed intake and body weight, so the lower end of this range is generally preferred 3, 6. For water-based delivery, efficacy was inconsistent, with only some doses showing benefit 7.

Neurological Dosage in Animal Models

Anticonvulsant effects in mice were seen at 10–30 mmol/kg when caprylic acid was administered orally, with higher doses increasing the seizure threshold. These findings have informed the use of caprylic acid-rich MCT oil as an adjunct in ketogenic diets for epilepsy, but direct translation of these doses to humans is not straightforward 2, 8.

Clinical and Dietary Dosage

In clinical nutrition, MCT oil (containing around 75% caprylic acid) is often used at doses of 10–30 grams per day, providing an energy source for patients with fat malabsorption or certain metabolic conditions 5. These dosages are generally well tolerated, but individual needs and tolerances can vary.

Safety and Titration

Key points for safe supplementation:

• Start with a low dose and gradually increase to minimize digestive discomfort.
• Monitor for any side effects, particularly gastrointestinal upset or changes in appetite.
• Consult a healthcare professional before starting caprylic acid supplementation, especially for those with liver or metabolic issues.

Conclusion

Caprylic acid is a versatile medium-chain fatty acid with a broad range of potential benefits, supported by a growing body of research. However, as with any supplement, understanding its effects—both positive and negative—and appropriate dosing is key to maximizing its potential.

In summary:

• Antimicrobial properties: Caprylic acid shows strong activity against several bacterial pathogens, especially in animal and agricultural settings 1, 3, 6.
• Neurological support: It demonstrates anticonvulsant effects in animal models, supporting its use in ketogenic diet therapy 2, 8.
• Anti-inflammatory and metabolic roles: May help reduce inflammation and improve lipid metabolism, with implications for cardiovascular health 4, 5.
• Side effects: Generally mild, but higher doses can cause digestive upset, weight changes, or appetite modulation 5, 6.
• Dosage: Effective doses vary by application; starting low and increasing gradually is recommended, with most human supplementation ranging from 10–30 grams per day as MCT oil 5.

As research continues, caprylic acid’s unique properties may find broader uses in health, nutrition, and disease management. Always consult a healthcare provider before beginning new supplements, especially at higher doses or for specific medical conditions.