If you’re following the keto lifestyle, chances are you’ve heard of MCT oil. This powerful supplement can boost energy, support fat-burning, and enhance mental clarity. But like any supplement, it can cause side effects if not taken correctly.

This article explores the potential side effects of MCT oil and how to avoid them, so you can enjoy all the benefits without the discomfort. Plus, we’ll introduce you to Planet Paleo’s gentler, more digestible options from our Keto Collection.

What is MCT oil?

MCT stands for medium-chain triglycerides, a type of fat that’s digested more quickly than long-chain fats. On a low-carb or ketogenic diet, MCTs are converted into ketones by the liver, which your body can use as a clean source of fuel for the brain, muscles and heart.

MCTs are found in coconut oil, palm oil, and some dairy products. The four types include caproic, caprylic, capric, and lauric acid. Of these, caprylic acid (C8) is the most efficiently converted into ketones.

Where does MCT oil come from?

Four different kinds of MCTs exist, including caproic acid, caprylic acid, capric acid, and lauric acid. Although these are found in foods such as palm oil and dairy products, by far the commonest source of MCTs is coconut oil, since 50% of its fats come from MCTs.

If you're exploring ways to support your energy levels and recovery alongside MCT oil, incorporating bone broth protein into your routine can be a great addition. It's rich in collagen, amino acids, and nutrients that complement the benefits of healthy fats and can be especially helpful for those with an active lifestyle. 

Is MCT oil good for you?

MCT oil contains an array of nutritional benefits, many of which are the subject of ongoing research:

• MCT oil may help weight management, especially when carbohydrate intake is low. This fat-burning state is called ketosis. MCT oil appears to improve self-reported feelings of satiety after eating due to its positive influence on hunger hormones such as leptin, as well as on triglycerides and glucose. MCT also has approximately 10% fewer calories than long-chain triglycerides, which are found in fatty foods such as olive oil, nuts, and avocados.

• MCT oil may positively impact sports performance by reducing lactate levels in the blood and helping athletes to train faster and for longer. Lactate can build up in muscles during intense exercise, causing burning and fatigue. Check out c8 mct powder if you want to improve your performance. Our powder has all the benefits of MCT oil and blends brilliantly into coffee, smoothies, or anything else!

• MCT oil may support the growth and maintenance of good microflora in the gut, playing a role in inflammation, weight management, mood and hormone balance.

• MCT oil has also been studied in the context of Alzheimer’s disease, epilepsy, and autism spectrum disorder alongside other protocols. However, more research is needed.

• Lastly, MCT oil is a powerful antimicrobial, which has shown to be effective against Candida albicans yeast infection, bacterial infections such as Clostridium difficile and other infectious bacterial and fungal pathogens. These effects are due to the caprylic, capric and lauric fatty acids contained in coconut oil. Coconut oil itself is a broad-spectrum antimicrobial which has been used as part of the Candida diet and other gut-healing modalities for decades.

Want the benefits without the gut drama? Try our Planet Paleo MCT Powder – a clean, easy-to-digest powder that blends seamlessly into coffee, smoothies or shakes.

5 side effects of MCT oil you should be aware of:

1. Immune Reaction & Flu-like Symptoms

Some people experience detox symptoms when first using MCT oil – like skin itching, brain fog, rashes or flu-like symptoms. This is often due to a Herxheimer reaction, caused by the die-off of harmful gut bacteria, yeasts or parasites.

How to fix it:

- Start with a very low dose (1/4 tsp every other day)

- Support detox with hydration and binders (e.g. activated charcoal)

- Use a gentler MCT source like MCT Power powder to reduce intensity

- Support liver detox with dandelion tea, vitamin C and glutathione

🍽️ Tip: Many people find powdered MCT easier on the gut. Our MCT Powder gives you all the benefits of MCT without the harsh reaction.

2. Diarrhoea and Loose Stools

Taking too much MCT oil too quickly can overwhelm the digestive system, especially in liquid form, leading to diarrhoea, cramping and gas.

How to fix it:

- Start slow and increase gradually

- Take MCT with food, not on an empty stomach

- Switch to a gentler powder version like our MCT Power

💩 Having gut issues with regular MCT? Our MCT Powder is designed to be easier on digestion. It's great for sensitive stomachs!

3. Constipation

Surprisingly, MCT oil can also cause the opposite issue: constipation. This may indicate your detox and elimination pathways are sluggish.

How to fix it:

- Increase hydration and fibre intake

- Use digestive-supporting supplements like ginger, magnesium or aloe

- Try Keto Collagen with gut-loving nutrients to ease digestion

💡 Our Keto Collagen blends MCT with collagen peptides for better gut support and

4. Brain Fog & Fatigue

While MCT oil is known for mental clarity, detox reactions can sometimes cause the opposite. If you're feeling groggy or foggy, your body might be struggling to eliminate toxins.

How to fix it:

- Stay hydrated and add electrolytes

- Support the liver with herbs like milk thistle

- Combine MCT with protein or adaptogens for balance

☕ Try our Keto Collagen + MCT in your morning coffee for sustained clarity and energy without the crash.

5. Fat Buildup in the Liver (Rare)

Consuming very large quantities of MCT oil over time might lead to fat accumulation in the liver, though this is rare and usually only in those consuming over 45g/day consistently.

How to fix it:

- Stick to the recommended dose: 5–15g/day

- Choose a balanced formula like our MCT Collagen blends

- Support liver health with bitters and antioxidants

How to Take MCT Oil Safely

- Start with 1/4 tsp per day and increase slowly

- Use powdered MCT for easier digestion

- Don’t take on an empty stomach if you're sensitive

- Stay hydrated with water + electrolytes

- Support detox with binders, vitamin C, glutathione

Best Products for People Sensitive to MCT Oil

- MCT Powder – easier on the gut, mixes into drinks

- Keto Collagen – combines MCT with protein for smoother digestion

- Keto Coffee – sustained energy + mental clarity without crashes

Final Thoughts: MCT Oil Side Effects vs Benefits

Yes, MCT oil can cause side effects – but they’re usually temporary and preventable. With the right dosage and product form, you can enjoy:

- Better energy

- Sharper focus

- Enhanced fat-burning

- Improved gut health

Make sure to choose high-quality, gentle MCTs like our Planet Paleo MCT Powder and start slowly. Listen to your body, support detox, and stay hydrated.