MCT oil and intermittent fasting - can they work together?
Or will MCT oil break a fast?
Some people say MCT oils break a fast completely and should be avoided, others claim it's perfectly fine for use during your fasting window.
The truth? It actually depends on why you're fasting in the first place...
What is MCT Oil?
MCT stands for medium-chain triglycerides, fats with shorter molecular chains than the long-chain fats you'll find in most cooking oils.
MCT oil is typically extracted from coconut oil and depending on the quality contains varying amounts of:
- C6 (Caproic acid) - rarely used due to unpleasant taste
- C8 (Caprylic acid) - converts to ketones fastest
- C10 (Capric acid) - provides sustained energy
- C12 (Lauric acid) - technically an MCT but behaves more like a long-chain fat
Unlike other fats that need bile acids and digestive enzymes to be processed by the body, MCTs zip straight from your gut to your liver where they're rapidly converted into ketones (which are your brain's preferred alternative fuel source).
This is why MCT oil feels completely different from other fats, and may even surprise you at first. No sluggish digestion, no heavy feeling afterwards, just a natural energy that your body can use right away.
Will Taking MCT Oil Break a Fast?
The truth is there's no one-size-fits-all answer.
What breaks a fast for someone seeking those much-sought-after autophagy benefits might be perfectly fine for someone focused more on metabolic flexibility.
Let's take a look at the different fasting goals you should be focused on as a starting point:
For Metabolic Flexibility and Fat Loss
If you're fasting to improve your metabolic health, lose weight, or enhance fat burning, MCT oil can actually support your efforts.
MCT oil doesn't spike insulin the way carbohydrates do. It rapidly converts to ketones, keeping you in that fat-burning state you're after. Some people find it helps them fast longer by reducing hunger pangs and providing steady energy.
Studies show that MCTs can increase energy expenditure and enhance the feeling of fullness. This means you might actually eat less throughout the day, even if you've technically "broken" your fast with a tablespoon of MCT oil.
For this type of fast, 1-2 teaspoons (5-10ml) during your fasting window is generally acceptable and may even enhance your results.
For Gut Health and Rest
This is where things get nuanced, so bear with me.
MCT oil affects your gut in two completely different ways, and understanding both helps you make better choices about your fasting routine.
Digestive Rest
MCT oil does need some digestive work, but for your guts, it's like comparing a gentle stroll to a marathon.
Unlike other fats that need your pancreas working overtime to pump out enzymes and your gallbladder squeezing out bile, MCTs take the express route straight to your liver via the portal vein.
Your digestive system gets to put its feet up compared to what it normally deals with.
Bioactive Intervention
Quality MCT oils pack loads of capric (C10) and caprylic (C8) acids, which are powerful fighters when it comes to combating harmful yeasts and bacteria in your gut.
So while you're giving your digestive organs a breather, you're also actively sorting out your microbiome!
These two effects usually work brilliantly together for general wellness. You get the rest benefits plus the antimicrobial cleanup.
But (there's always a but) if you're dealing with serious inflammatory gut conditions like severe IBD, Crohn's, or SIBO, and you're fasting specifically for therapeutic gut rest, introducing any bioactive fat might not be the smartest move.
Your gut might need a full rest, not the introduction of new oils.
The Coffee Factor
Did you know, If you're already having coffee during your gut-health fast (and loads of people do), you've already got digestive processes ticking over anyway.
Yes, even consuming near-zero-calorie black coffee kickstarts the production of digestive enzymes and stomach acid. Coffee's bitter compounds trigger these responses even without any actual calories hitting your system.
Adding a splash of MCT oil to that coffee isn't exactly breaking new ground - you're just adding a gentle fat to an already active system.
For Healthy Ageing and Longevity
If maximising autophagy is your main goal, MCT oil will technically break your fast. Simple.
Any caloric intake can reduce autophagy, and MCT oil is calorie-dense at around 8.5 calories per gram.
Autophagy - your body's cellular cleanup process - is triggered by energy restriction. When you consume MCT oil, you're providing external energy, which can slow down this beneficial process.
For autophagy-focused fasting, it's best to stick with water.
Save the MCT oil for your eating window.
How Much MCT Oil Should You Take While Fasting?
Most advice about using MCT oil during fasting is frustratingly vague. "Small amounts" doesn't help when you're standing there with a bottle of MCT oil in your hand, wondering if one tablespoon at a time will break your fast.
Here's what actually works based on your fasting experience:
If you're new to using MCT oil: Start with half a teaspoon (2.5ml = 21 calories) in your morning coffee. Your gut needs time to adapt to this type of fat. Taking too much MCT oil initially can cause stomach upset, loose stools, or nausea. Not exactly what you want during a fast!
For regular fasters: A small dose of MCT oil - up to one tablespoon (15ml = 126 calories) - during your fasting window provides solid ketone production without excessive caloric load. This amount technically breaks a fast, but MCT oil can be beneficial for maintaining energy and mental clarity.
For extended periods of fasting (24+ hours): Keep it to 1-2 teaspoons spaced throughout the day. During a long fast, even small amounts of calories become more significant. The goal is getting the benefits of MCT oil while preserving most benefits of fasting.
Daily limits matter: Even outside your fasting window, most people shouldn't exceed 3 tablespoons (45ml) daily. Your liver can only process so many ketones efficiently. Beyond that, excess gets stored as body fat like any other energy source.
If you experience digestive discomfort, scale back and build tolerance gradually over 2-3 weeks.
Best Time To Use MCT Oil While Intermittent Fasting
Getting your timing right is the difference between MCT oil being your fasting friend or foe.
The morning coffee move (Our favourite) Put a teaspoon of MCT oil in your coffee any time between 6-10am and you will have a nice boost of natural energy for hours.
The caffeine gets your fat-burning going while the MCTs keep your energy steady - no mid-morning crash, no breaking ketosis. It's a proper power combo.
Pre-workout fuel Half an hour before you hit the gym fasted? That's when MCT oil shines. You get the energy you need for a decent workout while still burning fat like a machine. Your body's basically running on two fat sources - what you've got stored plus the MCTs you just had.
The mid-fast rescue Doing a longer fast and hitting that wall around hour 16-20? We've all been there. Half a teaspoon of MCT oil will sort you right out without derailing all the good work you've done so far.
Match your timing to what you're looking to achieve:
Chasing fat loss? Get your MCT oil in early during your fasting window. You'll keep those ketones flowing and the fat burning going strong.
Need your brain switched on? Time it before you've got proper work to do. Those ketones will be feeding your brain within 30-60 minutes and perfect for when you need to be sharp for studying or tougher mental tasks.
Struggling with hunger? Take it when you usually start getting peckish. MCT oil's brilliant at keeping cravings in check, so you can push your fasting window that bit longer.
What's a waste of time: Don't bother with MCT oil if you're breaking your fast in the next couple of hours. And if you're sensitive to energy boosts, and avoid it late in the day unless you fancy feeling wired at bedtime!
Will MCT Oil Stop Autophagy During a Fast?
This isn't as black and white as most people make it out to be.
For those chasing maximum autophagy, a zero-calorie fast is your best bet - that's what the science backs up most strongly. Any calories you have, MCT oil included, give your body external energy and will likely dial down the main cellular signals that kick off this whole autophagy cleanup process.
But here's where it gets interesting (and a bit messy from a science perspective). Some research suggests that the ketones MCTs produce may actually stimulate certain protective autophagy pathways (like activating AMPK or inhibiting mTOR).
The problem? We're still figuring out what this all means in real humans doing real fasts.
The research is promising but it's not complete enough to give you a definitive answer.
MCT oil might offer some pathway-specific benefits, but if you want to play it safe and maximise the full-body autophagy cleanup, the purist approach is still to avoid all calories during your fasting window.
The real question isn't just about the science - it's about your own life and preferences.
What's better for you long-term? Sticking to perfect zero-calorie fasts that you struggle with and eventually abandon, or maintaining a consistent fasting routine with slightly less autophagy but way better compliance?
For most people, doing it consistently beats doing it perfectly every single time.
Does MCT Creamer Break A Fast?
MCT creamers are gaining popularity, but they're not the same as pure MCT oils, and shouldn't be confused with one another when it comes to fasting.
The short answer: Most MCT creamers will break your fast more significantly than pure MCT oil. They have additional ingredients and calories which you can't consume while in a fasted state.
Why MCT creamers are different
Unlike pure MCT oils, commercial creamers contain extras:
- Milk proteins (casein, whey) definitely break a fast
- Natural flavours (sometimes hiding sugars)
- Emulsifiers and stabilisers
- Sweeteners (even "natural" ones can affect insulin)
These additions increase calories and can trigger insulin responses that pure MCT oil typically avoids.
Better alternatives: If you want creamy coffee without breaking your fast as much:
- Use pure MCT oil with a splash of heavy cream
- Try our Thrive Coffee (combines MCTs, grass-fed butter, and premium coffee in one convenient powder)
- Blend pure MCT oil with coffee - creates natural richness
MCT creamers are convenient but not optimal for fasting. If you must use them, read labels carefully. Better yet, stick with pure MCT oils and add your own healthy fats.
MCT Powder Vs MCT Oil: Which Won't Break Your Fast?
Both forms have their place in a fasting regimen, but they work differently and suit different situations.
MCT Oil: The Pure Option
Pure MCT oils (like our Thrive Fuel range) contain just MCT oil with no additional ingredients. This makes them the cleanest choice for fasting periods.
Benefits for fasting:
- Pure fat source, no hidden ingredients
- Rapid absorption and ketone production
- Easy to measure precise doses
- Mixes well in hot drinks
Drawbacks:
- Can cause digestive upset in larger amounts
- Oily texture some dislike
- Liquid travel restrictions
MCT Powder: The Convenient Alternative
MCT powder is MCT oil spray-dried onto a carrier - usually acacia fibre (quality products) or maltodextrin (cheaper versions).
Benefits for fasting:
- Easier on digestion (fibre slows absorption)
- Travel-friendly and stable
- Dissolves cleanly in cold liquids
- Potential prebiotic benefits with acacia fibre base
Drawbacks:
- Slightly less ketone production due to slower absorption
- May contain carrier ingredients adding carbs
- Takes longer to feel effects
Our Thrive Fuel MCT Powder uses organic acacia fibre, not corn-based maltodextrin. This provides prebiotic benefits that can support gut health between fasting periods.
Which Should You Choose for Fasting? MCT Oil or MCT Powder?
Choose MCT oil if:
- You want maximum ketone production
- You're sensitive to any additives
- You primarily drink hot beverages
- You're experienced with MCTs
Choose MCT powder if:
- You're new to using MCT oil (gentler introduction)
- You travel frequently
- You prefer cold drinks
- You want added prebiotic benefits
For fasting purposes: MCT oil slightly edges out powder for pure fasting benefits due to faster absorption and ketone production. But if powder helps you maintain your fasting plan because it's more convenient, that consistency matters more than the marginal absorption difference.
Both technically break a fast but provide similar benefits for metabolic flexibility and appetite control during intermittent fasting.
Choosing The Right MCT Oil For Your Fasting Goals
When you're fasting and want to reap the benefits of MCT oil, quality matters even more.
Some MCT oils are cut with palm oil or processed with harsh chemicals, whilst others keep things pure and simple.
What Makes Hunter & Gather MCT Different
Whilst other brands cut corners, we triple steam distil our coconuts without hexanes or solvents. No palm oil, no vegetable oils, no artificial anything.
Our bottles are glass (not plastic), our powder uses organic acacia fibre (not cheap maltodextrin), and every batch gets tested for heavy metals and toxins.
Because when you're fasting for health benefits, the last thing you want is low-quality oils working against you.
For fasting purposes, start with our C8 & C10 blend - it's gentler on your system whilst still providing the ketone boost that makes fasting easier and more effective.
Hunter & Gather Thrive Fuel range: Built for Fasters
Thrive Fuel C8 & C10 MCT Oil: The balanced choice Our most popular MCT oil combines 60% C8 and 40% C10 fatty acids at just 126 calories per tablespoon (15ml). Made from 100% organic coconuts with triple steam distillation - no hexanes, no palm oil, no nonsense.
C8 gives you rapid ketone production, whilst C10 provides sustained energy. This blend works brilliantly for most fasters who want quick mental clarity without the digestive upset that pure C8 can sometimes cause.
Thrive Fuel Pure C8 MCT Oil: Maximum ketone power For those wanting the strongest ketogenic effect, our Pure C8 delivers over 98% caprylic acid. This converts to ketones faster than any other MCT, making it ideal if you're fasting specifically for mental clarity and cognitive performance.
Start with just 1 teaspoon (5ml = 42 calories) during your fast - pure C8 packs a punch and you don't want to overdo it initially.
Thrive Fuel C8 & C10 MCT Powder: Travel-friendly convenience Same quality MCTs but in powder form using organic acacia fibre (not corn-based maltodextrin like cheaper brands). Perfect if you're fasting on the go or prefer powder over oil.
At 10g per serving, you get the MCT benefits with added prebiotic fibre that supports gut health - particularly useful if you're alternating between fasting and gut-healing protocols.
Thrive Coffee: The all-in-one solution Can't be bothered with measuring oils? Our Thrive Coffee combines organic MCTs with grass-fed European butter and TrueStart coffee. Just add hot water and you've got a proper bulletproof-style coffee that supports your fast without the faffing about.
Each 20g serving gives you controlled caffeine (120mg), quality fats, and that creamy vanilla taste that makes morning fasts actually enjoyable.
MCT Oil Vs Other Fasting Supplements
MCT oil isn't the only supplement people ask about during fasting. How does it stack up against other popular options?
MCT Oil vs Collagen
Both can support different aspects of your fast, but they work differently. MCT oil provides immediate energy and ketones, whilst collagen supplies amino acids for muscle preservation and gut health. Many people use both - MCT oil for energy, collagen for protein support.
Check out our complete guide to collagen and intermittent fasting for the full breakdown.
MCT Oil vs Coconut Oil
Coconut oil contains some MCTs, but it's mainly lauric acid (C12), which behaves more like a long-chain fat. Pure MCT oil gives you concentrated C8 and C10 for faster ketone production and better fasting support.
Check out our article on MCT Oil vs Coconut Oil for more info.
Safety And Who Should Be Cautious With Mct Oil
MCT oil is generally safe but some people need extra caution. Knowing when to be careful helps you use MCT oil to give your body benefits without problems.
People with liver problems
Your liver does all the heavy lifting when it comes to processing MCTs. If you've got cirrhosis, hepatitis, or other serious liver conditions, consuming MCT oil puts extra strain on an organ that's already struggling.
If you have any liver issues, chat with your doctor before changing your diet or entering a fasting protocol. In most cases, it may be best to avoid MCTs entirely.
Uncontrolled diabetes
MCTs get quickly converted into ketones, which is usually brilliant. But if your diabetes isn't well managed, this rapid ketone production could push you toward diabetic ketoacidosis - a potentially dangerous situation that needs immediate medical attention.
If you're diabetic and want to use MCT oil during your fasting routine, work with your healthcare provider to make sure it fits safely into your management plan.
Cholesterol "hyper-responders"
Some people see their LDL ("bad") cholesterol shoot up when they consume lots of saturated fat, including MCT oil. If heart disease runs in your family or your cholesterol's already high, it's recommended that you take baseline blood work, then recheck after 2-3 months of using MCT oil.
Sensitive stomachs
If you're prone to digestive upset, IBS, or loose stools, introducing MCT oil needs a gentle approach. Start with quarter-teaspoon amounts and build up slowly. Taking too much too fast is a recipe for gastric chaos.
Gallbladder issues
Though MCTs don't need bile for digestion like other fats, people who've had gallbladder removal or have gallbladder problems should introduce MCT oil cautiously. Any dietary fat can potentially cause discomfort.
When to get professional advice
- You're on medication for diabetes, liver disease, or heart conditions
- You get persistent digestive problems even with gradual introduction
- You experience unexplained fatigue after starting MCT oil
- You're pregnant or breastfeeding (safety isn't well-established)
Remember, MCT oil supplements are meant to support your health, not replace proper medical care. When in doubt, err on the side of caution.
Common MCT Oil Fasting Mistakes
MCT oil fasting sounds straightforward, but there are some pitfalls that can trip you up. We've seen these mistakes countless times, so let's help you avoid them.
Going too hard, too fast
Your gut isn't ready for a massive dose of MCT oil on day one. Start small with just 1 teaspoon and work your way up slowly. Rush this, and you'll be dealing with an upset stomach that'll put you off fasting altogether.
Following someone else's playbook
Your mate who's fasting for weight loss has completely different needs to you if you're after the brain benefits. Don't copy their approach - figure out what works for your specific goals.
Skimping on quality
That bargain MCT oil might seem like a win, but if it's full of palm oil and nasty additives, you're setting yourself up for digestive drama. Plus, you won't get the clean, sustained energy that makes fasting worthwhile.
Terrible timing
Taking MCT oil just before you break your fast? You've just undone half the work. Give yourself proper spacing between your oil and your meals if you want the real benefits.
Waiting for miracles
MCT oil is brilliant, but it's not going to transform your life overnight. Think of it as your fasting sidekick - there to make things smoother and more manageable, not to do all the heavy lifting.
Expecting instant results
Your body needs a few weeks to get really good at using ketones for fuel. Don't throw in the towel after a few days because you're not feeling like a superhuman yet. Good things take time.
The Verdict: MCT Oil And Intermittent Fasting
Does MCT oil break a fast? Here's the honest answer:
Most people doing intermittent fasting will find MCT oil makes the experience more manageable. It provides clean energy, keeps hunger in check, and you still get the metabolic benefits you're after. But you need to be clear about what you're trying to achieve first.
MCT oil isn't the magic solution for every type of fast. If you're fasting for general health and weight management though (which covers most of us), it might be exactly what helps you stick with it long term.
Start with small amounts, see how your body responds, and choose quality MCT Oils that work with your goals.
All information provided on our website and within our articles is simply information, opinion, anecdotal thoughts and experiences to provide you with the tools to thrive.
It is not intended to treat or diagnose symptoms and is definitely not intended to be misconstrued for medical advice. We always advise you seek the advice of a trained professional when implementing any changes to your lifestyle and dietary habits.
We do however recommend seeking the services of a trained professional who questions the conventional wisdom to enable you to become the best version of yourself.
