Supplement analysis backed by scientific evidence · PT

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Moderate evidenceWeight management

MCT Oil

Replacing long-chain fats with MCTs produces a small but real reduction in body weight and fat mass, on the order of half a kilogram over a few weeks. Adding MCT oil on top of your existing diet just adds calories, and the cognitive claims are far weaker than the marketing suggests.

What the science says

  • Small weight and fat loss when substituted for other fats Moderate evidence

    A meta-analysis of 13 randomized trials found that replacing long-chain triglycerides with MCTs reduced body weight by about 0.5 kg, fat mass by about 0.4 kg and waist circumference by about 1.5 cm. The effect is small, was seen in substitution designs rather than addition, and long-term durability is unproven.

  • Raises blood ketones Strong evidence

    MCTs are absorbed via the portal vein and rapidly converted to ketones in the liver, so 15-30 g reliably raises blood beta-hydroxybutyrate within 1-2 hours without carbohydrate restriction. This is a well-established pharmacokinetic effect; whether the ketones deliver a clinical benefit is a separate question.

  • Cognition in mild cognitive impairment and Alzheimer's disease Limited evidence

    A 90-day randomized trial of a caprylic-triglyceride medical food (AC-1202) in 152 people with mild-to-moderate Alzheimer's found ADAS-Cog improvement only in the subgroup without an APOE4 allele, with no benefit in the overall intention-to-treat analysis at day 90. Subsequent work in mild cognitive impairment remains small and preliminary.

  • Endurance performance fuel Limited evidence

    Trials of MCT ingestion before or during endurance exercise have mostly failed to improve performance, and the doses required often cause GI distress that impairs it. This is not a supported ergogenic use.

Dosage & safety

Studied doseWeight-management trials used roughly 5-30 g/day substituted for other dietary fat. Ketone-raising and cognitive protocols use 15-30 g/day, usually split across meals. Start at 5 g/day and titrate up over 1-2 weeks to avoid GI distress. C8 (caprylic acid) raises ketones most efficiently.
SafetyDose-limiting side effects are GI: cramping, nausea, bloating and osmotic diarrhea, especially above 20 g in a single dose. It is pure fat at ~8.3 kcal/g, so adding it without removing other calories promotes weight gain. Contraindicated in people with hepatic encephalopathy or significant liver failure, since MCTs bypass normal fat handling and are metabolized directly by the liver. Caution with ketogenic diets in type 1 diabetes. Do not use MCT oil in coffee as a meal replacement expecting satiety benefits — protein and fibre do that far better.

Scientific references

Where to buy

Sports Research, Organic MCT Oil, Keto C8, 16 fl oz (473 ml)

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