What effect does MCT oil really have on your energy metabolism?
Does it help you lose weight?
Can it put you into ketosis?
Unfortunately, it’s time to bust a few myths: What MCT oil can actually do, where it falls short, and how to use it smartly.
What is MCT oil and how does it work?
People often confuse coconut oil with MCT oil. That’s not quite right.
MCT oils (medium-chain triglycerides – fats with 6–12 carbon atoms) are partially fast-digesting fats that the body can use quickly. This makes them behave differently in your metabolism compared to normal long-chain fats.
MCTs are often said to boost or even trigger ketosis. That’s a claim you should take with a big grain of salt. So let’s tackle this – probably the biggest myth – right away.
Every myth has a grain of truth. This one does too…
Does MCT oil put you into ketosis?
The right MCTs can trigger your body’s own ketone production – but only under specific conditions.
So, what are those conditions?
- Low blood sugar & low insulin
- A calorie deficit
- Plus, helpful factors like:
- Nearly empty glycogen stores
- Physical activity
- Fasting
It’s clear already: Drizzling a bit of MCT oil over your breakfast won’t magically put you into ketosis.
But it gets worse:
The ketosis boost from MCT oils is actually tiny – and comes at a high calorie cost.
First, only MCT 6 (caproic acid), MCT 8 (caprylic acid), and MCT 10 (capric acid) can potentially support ketosis – but only if all those conditions are met.
And here’s the kicker: Even then, the ketosis increase is extremely limited and requires consuming a lot of extra calories.
| Fatty Acid | Amount | kcal | BHB (mmol/L) |
|---|---|---|---|
| MCT 6 (C6) | 10 g | 90 | ~1.0 |
| MCT 8 (C8) | 10 g | 90 | ~0.6 |
| MCT 8 (C8) | 20 g | 180 | 1.0 – 1.5 |
| MCT 10 (C10) | 10 g | 90 | 0.3 – 0.6 |
| MCT 10 (C10) | 20 g | 180 | 0.6 – 0.9 |
| MCT 12 (C12) | 20 g | 180 | 0.1 – 0.2 |
As you can see: The longer the chain, the weaker the ketosis effect.
And by the way: Caproic acid (MCT 6) may look promising on paper, but it’s hard to find, hard to tolerate, and… it stinks.
So in real life, only MCT 8 and, with limitations, MCT 10 matter – and only in an actual calorie deficit combined with low-carb eating and at the cost of lots of extra calories.
By comparison:
A sachet of high-quality exogenous ketones has just 45 kcal and boosts ketosis by around 1.5 mmol/L – whether you eat carbs or not!
Blood BHB levels after taking Delta G, Ketone IQ, Prüvit, and Real Ketones – full test results coming soon.
So is MCT oil pointless? And what’s better?
MCT oil isn’t pointless at all. But it needs to be used wisely:
- To support a ketogenic diet
- During fasting
- In a well-designed bulletproof coffee
If you’re not doing keto or low-carb – and you’re already eating plenty of calories – adding another 90–180 kcal is just extra baggage.
And watch out: Pure coconut oil is even trickier. It only contains about 9–18% of the relevant MCT 6, 8, and 10 fats. Most of it is lauric acid (MCT 12) – which technically counts as an MCT, but barely boosts ketosis (see table above). That doesn’t mean coconut oil is bad for cooking – it’s just not really a ketone booster.
If you want an easy, convenient ketosis boost without ditching carbs or guzzling extra calories, exogenous k1 ketones are by far the better option.
MCT oil: Final thoughts and practical takeaways
For low-carb, fasting, or keto followers, MCT oil can be a useful tool. The key is to focus on MCT 8 and MCT 10 and ensure your insulin is low and you’re in a calorie deficit.
For everyone else, MCTs are basically just extra calories.
FAQs: Common questions about MCT oil
What makes MCT oils special?
MCTs bypass the usual lymphatic transport route. This means they don’t need fatty acid transporters and don’t enter the bloodstream as triglycerides. Instead, they go straight to the liver via the portal vein. There, they’re broken down through beta-oxidation into acetyl-CoA – which your liver can use to make ketones if insulin is low.
Important: This only applies to MCT-6, -8, and -10. And you need healthy beta-oxidation (a working fat metabolism).
Are MCT oils the same as exogenous ketones?
No. MCT oils are different. They can boost ketosis under certain conditions, but they’re nowhere near as effective as directly consuming exogenous ketones.
Is coconut oil the same as MCT oil?
No. Coconut oil contains some medium-chain fats, but the biggest part is lauric acid. This behaves like normal long-chain fats. True MCTs (caproic, caprylic, and capric acid) make up only 9–18%.
Sources
- Vetrani C, Verde L, Savastano S, Colao A, Muscogiuri G, Barrea L. Supplementation with medium-chain fatty acids increases body weight loss during very low-calorie ketogenic diet: a retrospective analysis in a real-life setting. J Transl Med. 2023 Jan 16;21(1):29. doi: 10.1186/s12967-023-03880-7.
- Lin TY, Liu HW, Hung TM. The Ketogenic Effect of Medium-Chain Triacylglycerides. Front Nutr. 2021 Nov 18;8:747284. doi: 10.3389/fnut.2021.747284.
- Nakamura K, Hagihara K, Nagai N, et al. Ketogenic effects of medium chain triglycerides containing formula and its correlation to breath acetone in healthy volunteers: a randomized, double-blinded, placebo-controlled, single dose-response study. Front Nutr. 2023 Sep 27;10:1224740. doi: 10.3389/fnut.2023.1224740.
- He H, Liu K, Liu M, et al. The impact of medium-chain triglycerides on weight loss and metabolic health in individuals with overweight or obesity: A systematic review and meta-analysis. Clin Nutr. 2024 Aug;43(8):1755-1768. doi: 10.1016/j.clnu.2024.06.016.
