How Many Relentless Energy Drinks Can You Drink In A Day? (Investigated)

A can of Relenless Energy Drink
The Relentless energy drink is originally made by The Coca-Cola Company in February 2006.

Relentless is a Coca-Cola owned energy drink brand mainly distributed in the UK but branch out internationally as well.

It’s a great-tasting energy drink uniquely formulated to power your day leaving you feeling refreshed and recharged after a draining work shift.

If you’re wondering how many Relentless energy drinks you can consume in a day, the answer is only 1 can of 500 ml per day.

Although Relentless contains a moderate dose of caffeine for a 500ml can, consuming this energy drink excessively will put your health at risk.

I know you’re interested to know more about this energy drink. Thus, I encourage you to read the entire article to help you gain a better understanding of why you should limit your consumption of this energy drink.

Also in this post, I’ll go over many aspects of Relentless energy drink such as the components and flavours, so stick with me until the end.

Let’s get started.

Relentless Energy Drink Ingredients

Each 500ml serving of Relentless energy drink contains the following ingredients:

  • Carbonated Water
  • Sucralose
  • Acid (Citric Acid)
  • Flavour Enhancer (Erythritol)
  • Taurine
  • Acidity Regulator (Sodium Citrate)
  • Preservatives (Potassium Sorbate, Sodium Benzoate)
  • Colour (Caramel E150d)
  • Caffeine (0.03%)
  • Flavourings
  • Sweetener (Sucralose)
  • Vitamins (B3, B5, B6, B12)
  • Guarana Seed Extract (0.005%)

Relentless Energy Drink Nutrition Facts

Relentless energy drink nutrition data.

The following are the nutritional information for Relentless energy drink, as listed in the table:

Standard ValueAmount Per 100mlAmount Per 500ml
Energy92 kJ
(22 kcal)
(108 kcal) (5%)
Carbohydrate6.1g31g (12%)
Of which sugars4.8g24g (27%)
Salt0.14g0.7g (12%)
Fat, saturates, protein – a negligible amount
*Reference intake of an average adult (8400kJ/2000kcal)
** Daily Reference Intake
Niacin (Vit B3)3.2mg (20%)16mg (100%)
Pantothenic Acid (Vit B5)1.7mg (28%)8.5mg (142%)
Vitamin B60.3mg (20%)1.5mg (107%)
Vitamin B120.4µg (15%)2.0µg (80%)

What Is The Caffeine Content of Relentless Energy Drink?

The caffeine content of a 500ml can of Relentless Energy Drink is 160mg. Although this doesn’t exceed the EFSA’s recommended daily caffeine limit of 400mg, I believe it’s still a significant quantity.

Aside from that, this energy drink also includes 24g of sugar and 31g of carbs all combined in one can.

Thus, if you take 2 cans of Relentless energy drinks a day, you consume a whopping 320mg of caffeine.

This is alarming since 320mg caffeine content is very close to the 400mg caffeine dose limit recommended by the EFSA, not to mention the additional caffeinated products and beverages you may be ingesting.

Take note that caffeine can be ingested safely in low to moderate doses. Furthermore, moderate caffeine use has the following advantages, according to this study:

  • Improves physical endurance
  • Enhance cognitive function
  • Increase alertness and concentration
  • Boost mood and reaction
  • Lower the risk of fatigue
  • Lower the risk of oral cancer
  • Lower the risk of strokes for older women

If you’re interested in learning more about the highly caffeinated beverages that dominate the energy drink sector, I’ve compiled a comprehensive list here.

Relentless Energy Drink Sugar Content

How much sugar can you consume on a daily basis?

The 500ml Relentless Energy Drink has 24g of sugar per can.

Is 24g of sugar a lot? This is a lot compared to other energy drink brands with low sugar counts.

According to National Health Service UK (NHS), the maximum amount of sugar you can consume in one day should be between 25g-30g.

Women and children over the age of two should consume no more than 25g of sugar per day, and men should take no more than 30g per day.

Based on this study, sugar when not overlooked is safe to consume. In fact, it has a number of advantages, including:

  • Gives you a surge of energy
  • Stock your energy to be utilized later
  • Immediately improve your mood
  • Help enhance your concentration

You can also check out my other article about sugar-free energy drinks if you’re sensitive to Relentless sugar content.

Relentless Energy Drink Calorie Content

The 500ml Relentless energy drink in an Origin flavour contains 108 calories. Keep in mind that the calorie content of this energy beverage varies depending on what version you purchase.

Additionally, these 108 calories will not cause a major impact on your diet. Based on the NHS calorie intake standards, 108 kcal does not exceed the recommended daily calorie consumption of 2,500-2,000 kcal for both men and women.

Your calorie requirements, on the other hand, may differ based on your age, gender, height, weight, and level of physical activity.

If you want to know more about calorie-free energy drinks, I posted a detailed article here.

Is Relentless Energy Drink Good For You?

Relentless energy drink is good for you as long as you’re not going overboard with your consumption.

I believe the 160mg of caffeine and 24g of sugar is enough to help you stay active and alert throughout your day.

However, if you have a medical issue and still wanted to try Relentless, I recommend talking with your doctor first to determine whether it is safe for you to ingest.

Is Relentless Energy Drink Bad For You?

Relentless is not harmful to your health as long as you take it sensibly. However, if you have poor caffeine tolerance or has a medical condition, then Relentless may put your health at risk.

Children, pregnant women, and caffeine-sensitive individuals are also off-limits to consume Relentless energy drinks.

  • Children

Children are not advised to consume energy drinks, particularly those with a large dose of caffeine. Nausea, vomiting, diarrhoea, extreme restlessness, and other side effects are possible to happen if consumed excessively.

  • Pregnant

Caffeine is also not recommended for pregnant women. Too much caffeine consumption during pregnancy has been linked to miscarriage and poor birth weight.

  • Caffeine sensitive

Individuals who have poor tolerance to caffeine are also not advised to consume Bang Shots and other highly caffeinated beverages for their health’s sake.

Once again, keep your intake to one can per day to avoid having major health issues. Always take your health into account whenever you consume any highly caffeinated beverages.

Does Relentless Energy Drink Really Works?

If you’re looking for a strong caffeinated beverage, you may want to give Relentless a shot.

It includes a whopping 160mg of caffeine, 24g, and 108 kcal all mixed inside the 500ml can. It also provides you with a number of advantages such as:

  • Feeling revitalized
  • Increase stamina
  • Enhanced mental ability
  • Improved athletic performance

Furthermore, it gives me the caffeine boost I need to keep me alert throughout my day. Thus, it works well for me.

However, what works for me may not work for you, so I recommend that you test it out for yourself.

If you want to learn more about Relentless energy drink, I posted a separate article here.

How Long Does It Take For Relentless To Kick In?

It takes about 10-15 minutes for a Relentless energy drink to enter the bloodstream.

Another 15-20 minutes for your body to completely absorb the caffeine.

So, if you’re going to the gym or pulling an all-nighter, I recommend drinking it 30-60 minutes ahead of time to get the caffeine boost you needed.

How Long Does A Relentless Energy Drink Last?

The caffeine in a 500ml Relentless energy drink can last up to 10-12 hoursCaffeine may still be present after some time has passed.

Always keep an eye on your caffeine tolerance. Consuming too much caffeine more than your body can handle will lead to caffeine overdose.

What Happens When You Drink Relentless Energy Drink?

Relentless energy drink is a great option if you’re looking for a caffeine boost. In every 500ml can, you’ll get a thumping 160mg of caffeine dose, 24g of sugar and 108 kcal.

Aside from that, it contains B vitamins (B3, B5, B6, and B12) that are proven to improve your concentration and performance.

Based on my experienced, taking a few sips of Relentless before hitting the gym was a great idea. I prefer to drink it while it’s cold for a more refreshing experience.

It also tastes sweet due to its sugar content. Lemon Ice is my favourite out of the seven flavours that I have tried so far. You can try experimenting with different flavours to see what suits you the best.

Although it feels a bit heavy on my stomach, I enjoy the light buzz effect it provides.

I decided to just grab a couple of them and consumes them like once or twice a week. I still drink plenty of water though to keep me hydrated.

How Many Relentless Energy Drink Can You Drink In A Day?

You should be aware that taking too much sugar or caffeine might be harmful to your health. As a result, consuming simply one can of Relentless energy drink is the ideal amount.

Relentless Energy Drink Side Effects

The following are the signs and symptoms of a caffeine overdose:

  • Sleep deprivation
  • Headache
  • Diarrhea
  • Heightened thirst
  • Dizziness
  • Irritability
  • Fever

You may also suffer from the following severe symptoms such as:

  • Difficulty in breathing
  • hallucinations
  • confusion
  • vomiting
  • chest pain
  • Occasional rapid heartbeat
  • convulsions
  • uncontrollable muscle movement

Another substance that you need to consider is sugar. Sugar is a vital source of energy, especially glucose.

However, excessive sugar consumption might lead to the following:

  • Addiction
  • Obesity
  • High blood pressure
  • Fatty liver disease
  • Chronic inflammation

Consuming too much sugar may also contribute to:

  • Fatigue
  • Acne
  • Weight gain
  • Increase the risk of type 2 diabetes
  • Incease the risk of heart disease.

If you have any of the following symptoms mentioned above, please seek medical attention immediately.

I’ve published a separate article about energy drinks’ adverse effects, which you can find here.

Relentless Energy Drinks Flavours

Relentless energy drink has the following flavours where you can choose from:

  • Origin (the original flavour)
  • Zero (sugar-free version)
  • Lemon Ice
  • Passion Punch
  • Cherry
  • Apple Kiwi
  • Mango
Watch this 6 minutes review of the Origin Flavour of Relentless Energy Drink.

How Much Is Relentless Energy Drink?

The 500ml can of Relentless energy drink cost approximately £1 or more, depending on your location.

If you think this is a bit pricey, try the Relentless 100ml version, which costs around £0.20.

Where Can I Buy Relentless Energy Drink?

Although Relentless Energy Drink is mainly distributed in the UK, you can still drop your order online.

The 500ml can of Relentless energy drink is available for purchase on Amazon and British Corner Store.

You may also visit their official website for more information.

Relentless Energy Drink Alternatives

If one doesn’t suit you, there’s a lot of option.

Although the Relentless energy drink is a great choice, you might want to try other brands as well.


If you’re looking for a strong caffeine boost, then Relentless is a good choice. It comes in a range of flavors that are specially crafted to keep you going throughout the day.

In addition to that, it has a fantastic taste at a reasonable price. The brand also includes B vitamins in their ingredients which is a huge plus for me.

Despite these promising benefits, I still recommend to restrict yourself to one can per day to avoid having major health problems.

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The only thing I like more than a delicious energy drink is uncovering the TRUTH about energy drinks. Well, that's a bit of an exaggeration, but I like to share the facts that I uncover and I hope you find my words interesting and useful.

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