MCT Oil Benefits: Weight Loss Evidence, Ketones and Side Effects

MCT oil benefits are real but modest. MCT oil is a concentrated fat made mostly of caprylic acid (C8) and capric acid (C10), which the body absorbs and uses for fuel more quickly than the fats in most foods. That is why it raises blood ketones, and why trials that swapped it for other oils found slightly more weight loss, about half a kilogram on average in a 2015 analysis of 13 trials. It is not the same as coconut oil, it still carries plenty of calories, and stomach upset is the most common complaint. In supplements, MCT oil is usually a carrier for other ingredients rather than the active part. Here is what the research shows and how to read labels that list it.

Peptide Labs sells products that contain MCT oil, but this article does not recommend any of them. It is general information, not medical advice.

What is MCT oil?

MCT stands for medium-chain triglycerides, fats built from fatty acids that are 6 to 12 carbon atoms long. Most of the fat in food is long-chain, with 14 or more carbons. According to a 2022 review in Frontiers in Nutrition, commercial MCT oils are made almost entirely of C8 and C10, with very little C12, and are produced from coconut or palm kernel fat. Some products are more than 95% C8.

Chain length changes how the fat is handled. Long-chain fats are packaged into particles that travel through the lymph system first. Most medium-chain fats skip that step and go straight to the liver through the portal vein, where they are used for energy or turned into ketones. The same review notes that hospitals have used MCTs since the 1950s as an energy source for people who cannot absorb normal fats, which is a medical nutrition use rather than a supplement benefit.

Is coconut oil the same as MCT oil?

No. Coconut oil is mostly lauric acid, a 12-carbon fat that behaves partly like a long-chain fat: only about 60% of it takes the direct route to the liver, compared with almost all C8. In a 2017 Canadian study of nine adults, coconut oil’s peak ketone rise was only a quarter of pure C8’s. A small UK study found that an MCT oil smoothie made people eat less at lunch than the same smoothie made with coconut oil, and its authors concluded that coconut oil cannot be promoted as having MCT oil’s effects. A 2020 meta-analysis in Circulation also found that coconut oil raised LDL cholesterol compared with non-tropical vegetable oils.

MCT oil benefits: what the research shows

Ketones

Because the liver turns some medium-chain fat into ketones, MCT oil can raise blood ketone levels even when you eat carbohydrates. In the 2017 crossover study, pure C8 produced the largest ketone response, classic C8 and C10 blends came next, and coconut oil the least. These are short, small lab studies measuring blood levels, not health outcomes. MCT oil makes the body produce ketones, while exogenous ketone supplements supply a ketone directly; our guide compares the two approaches.

MCT oil for weight loss

The research on MCT oil for weight loss comes largely from a group led by Marie-Pierre St-Onge. In a 2003 trial of 19 men, four weeks on an MCT-rich diet led to slightly more weight loss than four weeks on olive oil, and the extra energy use was smaller in heavier men. In a 2008 trial, adults in a 16-week weight-loss program who used MCT oil instead of olive oil ended about 1.7 kg lighter, though only 31 of 49 participants finished.

A 2015 meta-analysis of 13 randomized trials with 749 adults found that replacing long-chain fats with MCTs reduced body weight by about half a kilogram on average, with small drops in waist size and body fat. The authors detected commercial bias, noted that many trials lacked the details needed to judge quality, and called for large independent studies. The key word is replacing: the trials swapped MCT oil for other fats, rather than adding extra oil to a normal diet. For context on how much any supplement can shift energy use, see our guides on boosting metabolism and whether fat burners work.

Appetite, fullness and exercise

In the small UK study above, MCT oil at breakfast increased fullness and reduced how much people ate at lunch, but it was a single-day test. Exercise results are less encouraging. The 2022 review summarizes studies in which MCTs taken before exercise did not increase fat use during exercise or improve performance compared with carbohydrate, and high amounts caused diarrhea in some participants.

MCT oil and cholesterol

MCTs are saturated fats, so their effect on blood lipids is a fair question. The 2015 meta-analysis found no differences in blood lipids, and a 2008 trial found no worsening of metabolic risk factors with MCT oil compared with olive oil. A 2021 meta-analysis of seven randomized trials found that MCT oil did not change total, LDL or HDL cholesterol overall, but it raised triglycerides slightly. The comparison mattered: when MCT oil replaced mostly unsaturated oils such as olive or canola, total and LDL cholesterol went up. If your cholesterol or triglycerides are high, ask your clinician before adding MCT oil to your diet.

MCT oil side effects and who should be careful

The most common MCT oil side effects involve the gut. Cleveland Clinic notes that large amounts of MCT oil or powder may cause abdominal pain, nausea, vomiting and diarrhea. Other points to weigh:

• Calories: MCT oil is pure fat. A CBD tincture made with it lists 10 calories and 1 gram of fat per dropper, and a spoonful of the oil itself adds far more.
• Triglycerides: pooled trials found a small rise, which matters if yours are already high.
• Liver or heart conditions: a Cleveland Clinic dietitian advises against it for people with fatty liver or heart disease because MCTs are still fats; ask your clinician first.
• Coconut sensitivity: most MCT oil is made from coconut or palm kernel. Since January 2025, the FDA no longer lists coconut as a tree nut allergen, so coconut-derived ingredients will not appear in a “Contains” statement, though they must still appear in the ingredient list.
• Pregnancy, breastfeeding, diabetes or a medically supervised diet: check with your care team before adding concentrated oils or ketone-raising products.

Stop and get medical care for severe abdominal pain, persistent vomiting or signs of dehydration.

MCT oil in supplements: usually a carrier

Search a supplement catalog for MCT and most hits are not MCT products at all. MCT oil is a common carrier oil in CBD tinctures and softgels, and it appears in small amounts in many gummies. Three labels we carry show the range:

• Medterra Daily Relief CBD Isolate oil has just two ingredients, CBD isolate and organic MCT oil, and lists 10 calories and 1 gram of fat per dropper serving. That is far less MCT oil than the daily amounts tested in weight trials. Our guide to CBD oil and gummies explains how carrier oils fit in.
• Goli Pre+Post+Probiotics gummies list MCT oil among the other ingredients, after tapioca syrup, cane sugar and pectin, which is typical of how it is used in gummies.
• Herbtonics Apple Cider Vinegar + Keto Advanced includes MCT oil powder from coconuts in a blend with apple cider vinegar, berberine and Ceylon cinnamon, plus raspberry ketones. The blend name references GLP-1, but it is a dietary supplement, not a GLP-1 medication, and the label does not show how much of the blend is MCT.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Exogenous Ketones: What BHB Salts and Ketone Esters Do, and What They Don’t, CBD Gummies vs Oil: Absorption, Label Amounts, Sugar and Softgels, How to Boost Metabolism: What Really Changes the Calories You Burn.