Dave Asprey wrote this article a while back, and he does a great job at explaining (while citing the science) the difference between regular coconut oil, MCT oil, and his own Brain Octane and XCT oils. Should you need any of his products, they can be found here.
Coconut Oil vs. MCT Oil vs. Lauric Acid: What Is MCT Oil Really?
If you’ve been drinking Bulletproof Coffee made with XCT Oil or Brain Octane, you’ve already felt the powerful impact some types of MCT oil have on your energy.
However, there are a bunch of forms of MCTs – some real, some mostly made up by marketing, and not all forms of so-called MCTs are equally effective. That’s why I specify the exact types of oils that work best in The Bulletproof Diet, and why Bulletproof manufactures XCT Oil and Brain Octane Oil, neither of which is the plain “MCT oil” found in coconut oil.
The coconut oil industry loves to market the idea that coconut oil is a great source of MCTs because it’s “62% MCT oil” – but is that really true? What does that mean to you?
Don’t get it wrong – just about all the cheap and abundant oils in coconut oil are good for you, which is why coconut oil is high on the list of Bulletproof foods! The problem is that studies show you can’t get enough of the really useful MCTs from just eating coconut oil or a so-called “MCT oil” that is diluted with lauric acid, a useful, but cheap, and hugely abundant part of coconut oil that is marketed as an MCT oil.
- Coconut oil is good for you. Eating it provides cheap and abundant lauric acid, a useful oil that is sold as an MCT oil even though it does not act like an MCT in the body.
- In the US, coconut oil and MCT oil manufacturers are legally allowed to claim that lauric acid is an MCT because chemists named it that way, even though biochemists recognize that it does not act like other true biological MCT oils.
- If you are counting on plain coconut oil or “MCT-labeled” oil to get enough useful MCTs, think again and check the label: odds are you’re getting very few of the potent shorter chain MCTs (C8 and C10), and lots of the cheaper but ineffective lauric acid.
This post explores the science of how medium chain triglyceride (MCT) oils work, which types are best for what purposes, and why some kinds of MCT cause disaster pants and throat irritation and others don’t.
The Three True Biological MCT Oils: Why lauric acid acts like an LCT, not a real MCT
Coconut oil marketers often say there are four kinds of MCT oils found in coconut oil: C6, C8, C10, and C12 (the numbers define the length of the carbon chains).
Even though chemists long ago decided to call all of these MCTs, biologists now understand that the cheapest and most common of the MCTs, C12 or lauric acid, is actually a pseudo-MCT.
Lauric acid is a good food source, but it behaves like an LCT (long chain triglyceride) not an MCT, when you consume it, which means you don’t get the fast ketone energy from it that you can get from C8 or C10.
From a biology perspective, lauric acid should actually be considered a LCT; unlike the biological MCTs, lauric acid gets processed by your liver. This matters because your body metabolizes MCTs differently than LCTs; unlike LCTs, MCTs get very quickly converted into energy to fuel your brain and body instead of requiring a pit stop in the liver for processing.
Chemists counted the number of carbon chains and arbitrarily decided what was medium. Lauric acid is a chemical MCT but it is not a true biological MCT because our bodies do not treat it as an MCT. And nearly every study about the human and animal uses of MCTs you’ve ever seen does not measure lauric acid for this reason.
Don’t take my word for it – you can hear a lot more about this in Bulletproof Radio episode #151 with Melinda Culver, PhD, where we go into the science behind MCTs.
Since your body treats lauric acid differently from the get go, it deserves to be treated honestly on oil marketing labels too! Hopefully, chemists will eventually change the classification to be more accurate. Lauric acid is not an MCT.
So what *is* MCT Oil?
What Is MCT Oil: The Official List of MCTs In Coconut Oil
These are several main types of fatty acid oils found in coconut oil, but only the first 3 below behave in your body as real MCTs. This means that they bypass the metabolic burden of processing in the liver so they quickly become energy in your brain and muscles.
C6, Caproic Acid:
There’s not enough of it to matter in coconut oil, it tastes bad, and it often results in stomach/gastric upset, but it converts quickly to ketones! If your generic MCT oil makes your throat burn or has a weird flavor, one reason may be that the distillation did not remove enough of the C6. There are other reasons this can happen too, covered below.
C8, Caprylic Acid (Brain Octane)- The rarest ~6% of coconut oil:
It has potent anti-microbial properties (way more potent than lauric acid) to help you maintain a healthy gut, and it is the fastest to metabolize in the brain. (This is Brain Octane Oil.) Your liver does not need to process this rare type of MCT, and it only takes 3 steps for your body to turn it into ATP, the cellular fuel you use. Sugar takes 26 steps. This is why Brain Octane is so good at suppressing cravings and is the most powerful oil to put in Bulletproof Coffee. You would need 18 tablespoons of coconut oil to get just one tablespoon of Brain Octane.
C10, Capric Acid – Around ~9% of coconut oil:
This is the second shortest form of MCT, also rare. It is slower to turn into energy but more affordable than C8. XCT Oil is triple-distilled in a non-oxygen atmosphere with no solvents ever used, and it contains C10 and C8, because these are the only two MCT oils that turn into ATP quickly without the liver. You would need 6 tablespoons of coconut oil to get one tablespoon of XCT oil.
C12, Lauric Acid: Around ~50+% of coconut oil:
It requires a pit stop in the liver rather than getting immediately converted into energy like the other MCTs above. This is why it is more accurately described as an LCT, not an MCT like marketers claim. It raises cholesterol more than any other fatty acid (not necessarily a bad thing.) It is also commonly cited as having antimicrobial benefits, which is does…except the shorter chain MCT oils are more effective against aggressive candida yeast and even gonorrhea and chlamydia (as a monoglyceride). 
It’s confusing because coconut oil marketers imply that lauric acid is the same as monolaurin, an extremely potent antimicrobial that is derived from lauric acid. (They are not the same…I used monolaurin when I had candida years ago, and depending on your gut bacteria, you may create monolaurin in your gut when you eat affordable coconut oil.) Given how common and cheap this stuff is, it’s no wonder that companies are tempted to sell it as a true MCT. Two years ago, I looked into making a more affordable MCT oil containing lauric acid. I’d have made a killing selling what is basically coconut oil as something special, but it simply doesn’t work, and it’s not truthful marketing.
C-14 and above:
These are the widely recognized LCTs, or long chain fatty acids in coconut oil, mostly saturated, including stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (18:2). The exact percentage of each depends on region the coconut is grown, time of harvest, and other growing variables. They are good as a fuel source, but they are also widely available in other oils, and you won’t benefit from eating a lot more of them compared to eating true medium chain fatty acids.
Check The Label On Your “MCT Oil” For The Right MCTs
Lauric acid has a few antimicrobial benefits, which I’ll write another post on soon, but it’s simply not the most effective way to fuel your brain and body. It does not create energy in the brain the way that biological true MCTs, such as XCT or Brain Octane, do. 
So if you want lauric acid – and you do because it’s good for you – then don’t waste your time and money separating it out of coconut oil: just eat some coconut oil. And enjoy that coconut oil, because it’s both delicious and abundant in this nice fat.
You can get abundant lauric acid by just eating a tablespoon or two of coconut oil; there is no benefit to refining it and buying it separately when it’s so common in plain coconut oil. If you use cheap lauric acid to cut the potency of true biological MCT oil, you’re making it so weak that you’re not going to feel the energy effects that come from the much more powerful C8 or C10 MCTs found in XCT or Brain Octane.
MCT oil that’s cut with the cheaper lauric acid will only be about 1.5-2x as strong as coconut oil, but it will be far cheaper to produce. XCT oil is 6x stronger, and Brain Octane is up to 18x stronger.
MCT Oil Purity Matters Too
The reason I decided to create XCT and Brain Octane oils is that when I started learning about these types of lipids years ago in my anti-aging work at SVHI, it was common for our members – and for me – to get severe diarrhea and throat irritation from commercially available MCT oils.
We thought it was just an individual tolerance issue, but I soon discovered that it was an oil purity issue.
The reason purity matters is that C17 is a byproduct of other MCT oil production processes, and it, along with C6, is a major cause of disaster pants and irritation. There’s a reason that some MCTs cause problems when the same amount of Bulletproof XCT or Brain Octane won’t.
That’s why the unique process we use at Bulletproof is completely chemical and solvent-free. Most MCT’s on the market are manufactured via chemical/solvent refining, which can require using chemicals like hexane and different enzymes and combustion chemicals, such as sodium methoxide. The oils used to make MCTs – palm and coconut – are often solvent extracted too, but not Bulletproof.
We never allow solvents anywhere near our process. We use triple steam distillation in a non-oxygen atmosphere to avoid lipid oxidation and create a purer process. And we do it 100% in the United States. To my knowledge, no other company uses such extensive distillation to ensure purity, simply because solvents and catalysts are cheaper.
So that’s it – to have the most energy and the fewest cravings, you want the shortest chain possible, C8, with the highest levels of purity.
Brain Octane Oil vs. XCT Oil: Which Is Best For Me?
You’d get sick if you had 18 tablespoons of coconut oil, but you’ll feel great on 1 tablespoon of Brain Octane, the most potent extract of coconut oil (caprylic acid).
If you really want to take advantage of the most powerful medium chain fatty acids and the rarest parts of coconut oil, you’ll benefit the most from the cognitive aspects of an ultra-distilled, upgraded MCT like Brain Octane Oil (pure C8) or XCT Oil (C8 and C10).
So which to pick?
Brain Octane (Pure C8) provides the fastest rise in energy and focus and it’s what I start my day with. XCT (Upgraded MCT Oil) is more affordable but works more slowly with less direct cognitive effects. Both help your metabolism to burn fat.
The capric acid in XCT Oil doesn’t break down into ketones as quickly as pure caprylic, but capric acid is more affordable (but still works) so you can save money by going with the XCT. XCT Oil still goes to brain energy, just not as quickly as Brain Octane. Both can be used for energy without processing by the liver, unlike many other fats and oils.
- Use Brain Octane Oil if you want the maximum cognitive benefit and quickest digestion.
- Use XCT Oil if you are looking to economize while getting a metabolic boost and a slower smaller cognitive effect. (Or if you are using it externally for your hair or skin!)
Some people mix different ratios of each.
When to use coconut oil, then? If you love the taste or want ample lauric acid, eat it and enjoy it! Just know it is not the single strongest source of MCTs for fueling your brain and body.