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MCT oil

Two meta-analyses find replacing long-chain fats with MCTs lowers body weight by about 0.5 to 0.7 kg over weeks, with commercial bias noted. Energy intake at the next meal fell. Pooled trials in mild cognitive impairment and Alzheimer's disease show small cognitive gains. Triglycerides rose slightly. Large doses during exercise caused cramping and slower performance.

Add to Bio HackChecked 2026-11-09
Status
Food and dietary supplement in the US.
Also called
medium-chain triglycerides, medium-chain triacylglycerols, MCTs, MCFAs, caprylic acid, C8, capric acid, C10, coconut MCT, bulletproof coffee oil
Taken for
fat loss, weight loss, appetite, ketosis, energy, brain health, memory, Alzheimer's disease, endurance

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help4

Reported risks2

What people take it for, and what was found

Shown to help4

Strong

Body weight and body fat

Shown to lower body weight about 0.5 to 0.7 kg against long-chain fats in healthy adults, with smaller waists and less body fat.

The numbers and sources
Effect
Across 13 RCTs (749 participants), MCTs compared with long-chain triglycerides lowered body weight by 0.51 kg (95% CI -0.80 to -0.23), waist circumference by 1.46 cm and total body fat by SMD -0.39 [1]. Across 11 RCTs, body weight fell by 0.69 kg (95% CI -1.1 to -0.28), body fat by 0.89 kg and waist circumference by 1.78 cm [2].
Population
Healthy adults in trials longer than 3 to 4 weeks, replacing at least 5 g of dietary long-chain fat [1][2].
Sources
[1], [2]
Caveats
Commercial bias was detected and many trials lacked information for a full quality assessment [1]. Overall evidence quality was low to moderate [2]. The comparison is against other fats, not against no added oil.
Moderate

Appetite and food intake

Shown to lower how much people ate at laboratory meals compared with long-chain fats, with little change in appetite ratings or hormones.

The numbers and sources
Effect
Across 11 studies, MCTs lowered ad libitum energy intake compared with long-chain triglycerides (effect size -0.444, 95% CI -0.808 to -0.080). Subjective appetite ratings and appetite hormones showed little change [3].
Population
291 participants in 17 laboratory studies [3].
Sources
[3]
Caveats
Laboratory meals, mostly single sessions.
Limited

Memory in older adults without dementia

Small trials found improved memory, mainly working memory, in 4 of 6 trials in older adults without dementia.

The numbers and sources
Effect
In 6 RCTs, 4 reported improved memory measures, mainly working memory. No meta-analysis was run [7].
Population
Non-demented older adults [7].
Sources
[7]
Caveats
Few studies. Two used a ketogenic meal rather than MCT oil alone.
Limited

Cognition in young adults

One trial found better inhibitory control after one dose and better working memory after 4 weeks than olive oil, in young adults.

The numbers and sources
Effect
Against olive oil, a single 12 g dose of MCT gave better inhibitory control 75 minutes later (P < 0.05). After 4 weeks of daily MCT, working memory was better than after olive oil (P = 0.04) [8].
Population
36 adults aged about 21, randomized to MCT or olive oil [8].
Sources
[8]
Caveats
One small trial. The abstract reports p-values without effect sizes. The single-dose gain in inhibitory control was not seen after 4 weeks.

Mixed results1

Moderate

Cognition in mild cognitive impairment and Alzheimer's disease

Mixed results: reviews agree MCTs raise ketones in mild cognitive impairment and Alzheimer's, but differ on how consistently cognition improved.

The numbers and sources
Effect
Across 12 records (422 participants), MCTs raised beta-hydroxybutyrate by 0.355 mM and improved a combined ADAS-Cog and MMSE measure (SMD -0.289, 95% CI -0.551 to -0.027) [4]. A 2023 meta-analysis found general cognitive improvement (SMD 0.64, 95% CI 0.05 to 1.24) but not in memory, language or attention, with larger effects in APOE ε4 non-carriers [5]. A third review found cognitive results ranging from no improvement in 4 studies to improvement in 8 [6].
Population
People with mild cognitive impairment or Alzheimer's disease [4][5][6].
Sources
[4], [5], [6]
Caveats
The reviews agree MCTs raise ketones but differ on how consistent cognitive effects are. Risk of bias in existing studies was noted [4].

Not shown to help1

Limited

Endurance performance

Small trials found no endurance gain in cyclists. One found a slower time trial with MCT, and a large dose cut power 17 to 18%.

The numbers and sources
Effect
In 8 cyclists, adding MCT to carbohydrate did not improve a 100 km time trial beyond carbohydrate alone (169 versus 166 minutes) [9]. In 8 cyclists over 270 minutes, MCT with carbohydrate made the final time trial slower than carbohydrate alone (14:30 versus 12:36) [10]. In 7 cyclists, 85 g of MCT alone lowered time-trial power by 17 to 18% compared with placebo [11].
Population
Endurance-trained cyclists [9][10][11].
Sources
[9], [10], [11]
Caveats
Small crossover trials from 1998 to 2005. None found a gain.

Doses studied

Body composition trials replaced at least 5 g a day of dietary long-chain fat with MCT for at least 4 weeks [2]. Exercise trials gave 32 g before and a 4.3% MCT solution during exercise [10], a 4.2% MCT solution [9], or 85 g in total over 2 hours [11].

Risks

Reported risks1

Limited

Gut cramping during exercise

Small trials found gut symptoms in half of cyclists during a long ride, and cramping after 85 g taken during exercise.

The numbers and sources
Effect
Half the cyclists had gut symptoms with MCT during a 270-minute ride [10]. Intestinal cramping accompanied the 17 to 18% drop in time-trial power after 85 g of MCT [11].
Population
Endurance-trained cyclists [10][11].
Sources
[10], [11]
Caveats
High doses taken during exercise. Symptoms at doses taken with meals were not reported in these abstracts.

Mixed results1

Moderate

Blood lipids

Mixed results: one review found triglycerides rose and cholesterol depended on the fat replaced, while another found no lipid differences against long-chain fats.

The numbers and sources
Effect
Across 7 trials, MCT oil did not change total, LDL or HDL cholesterol overall but raised triglycerides by 0.14 mmol/L (95% CI 0.01 to 0.27). Compared with mainly unsaturated oils, MCT oil raised total and LDL cholesterol. Compared with longer-chain saturated fats, there was some evidence of reductions [12]. A separate meta-analysis found no differences in blood lipids compared with long-chain triglycerides [1].
Population
Adults in randomized trials of at least 2 weeks [12].
Sources
[1], [12]
Caveats
The direction of the cholesterol effect depends on which fat MCT replaces [12].

Claims tested and not found

  1. That MCT oil improves endurance. Adding MCT to carbohydrate did not improve cycling time trials, and larger doses slowed them [9][10][11].

Sources

  1. Mumme K, Stonehouse W. Effects of Medium-Chain Triglycerides on Weight Loss and Body Composition: A Meta-Analysis of Randomized Controlled Trials. Journal of the Academy of Nutrition and Dietetics. 2015. https://doi.org/10.1016/j.jand.2014.10.022
  2. Bueno NB, de Melo IV, Florêncio TT, et al. Dietary Medium-Chain Triacylglycerols versus Long-Chain Triacylglycerols for Body Composition in Adults: Systematic Review and Meta-analysis of Randomized Controlled Trials. Journal of the American College of Nutrition. 2015. https://doi.org/10.1080/07315724.2013.879844
  3. Maher T, Clegg ME. A systematic review and meta-analysis of medium-chain triglycerides effects on acute satiety and food intake. Critical Reviews in Food Science and Nutrition. 2020. https://doi.org/10.1080/10408398.2020.1742654
  4. Avgerinos KI, Egan JM, Mattson MP, et al. Medium Chain Triglycerides induce mild ketosis and may improve cognition in Alzheimer's disease. A systematic review and meta-analysis of human studies. Ageing Research Reviews. 2020. https://doi.org/10.1016/j.arr.2019.101001
  5. Sun L, Ye KX, Wong HLK, et al. The Effects of Medium Chain Triglyceride for Alzheimer's Disease Related Cognitive Impairment: A Systematic Review and Meta-Analysis. Journal of Alzheimer's Disease. 2023. https://doi.org/10.3233/jad-230406
  6. Castro CB, Dias CB, Hillebrandt H, et al. Medium-chain fatty acids for the prevention or treatment of Alzheimer's disease: a systematic review and meta-analysis. Nutrition Reviews. 2023. https://doi.org/10.1093/nutrit/nuac104
  7. Giannos P, Prokopidis K, Lidoriki I, et al. Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials. BMC Geriatrics. 2022. https://doi.org/10.1186/s12877-022-03521-6
  8. Yuuki IW, Dora K, Matsumura T, et al. Both a single dose and a 4-week daily regimen of medium-chain triglycerides boost certain aspects of cognitive function in young adults: A randomized controlled trial. Physiology & Behavior. 2026. https://doi.org/10.1016/j.physbeh.2025.115212
  9. Angus DJ, Hargreaves M, Dancey J, et al. Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance. Journal of Applied Physiology. 2000. https://doi.org/10.1152/jappl.2000.88.1.113
  10. Goedecke JH, Clark VR, Noakes TD, et al. The Effects of Medium-Chain Triacylglycerol and Carbohydrate Ingestion on Ultra-Endurance Exercise Performance. International Journal of Sport Nutrition and Exercise Metabolism. 2005. https://doi.org/10.1123/ijsnem.15.1.15
  11. Jeukendrup A, Thielen J, Wagenmakers A, et al. Effect of medium-chain triacylglycerol and carbohydrate ingestion during exercise on substrate utilization and subsequent cycling performance. The American Journal of Clinical Nutrition. 1998. https://doi.org/10.1093/ajcn/67.3.397
  12. McKenzie KM, Lee CM, Mijatovic J, et al. Medium-Chain Triglyceride Oil and Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Trials. The Journal of Nutrition. 2021. https://doi.org/10.1093/jn/nxab220

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