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Can You Drink Relentless Energy Drink Every Day? (Revealed)

Relentless energy drink is produced in Ireland and distributed in the UK. The drink comes in various flavours and has a brand image that emphasizes art, history, passion, and lifestyle.

If you’re in the UK, you probably stumbled upon a can of Relentless, or maybe you love drinking Relentless.

Can you drink a Relentless energy drink every day?

You can drink Relentless every day but only in specific amounts and in moderation. If you consume it daily, you must keep an eye on particular points, which I’ll discuss in this post.

Let’s get started.

What Are The Ingredients Of Relentless?

A single 500ml can of Relentless has the following ingredients, based on the original flavour:

  • Carbonated water
  • Sucrose
  • Sucralose
  • Citric acid
  • Erythritol (flavour enhancer)
  • Taurine (0.4%)
  • Sodium citrate (acidity regulator)
  • Potassium sorbate
  • Sodium benzoate
  • Caramel E150d (colour)
  • Guarana seed extract

Nutrients Of Relentless

Every 500ml can of Relentless has these nutrients in them. Check out the table for a better outlook:

Nutrients AppliedAmount Per Serving (500ml)
Total Carbohydrate31g
Total Sugar24g
Niacin (Vitamin B3)16mg
Pantothenic Acid (Vitamin B5)8.5mg
Vitamin B61.5mg
Vitamin B122.0 ug
Energy108 calories
Nutrition facts of Relentless energy drink.
A photo of nutrition facts at the back of the can.
Nutrition label of Relentless energy drink.

How Much Caffeine Does Relentless Energy Drink Have?

Every 500ml can of Relentless has 160mg of caffeine in them.

For starters, if you’re drinking one can of Relentless in a day, 160mg of caffeine is okay. But more than one can be harmful.

It all depends on your caffeine tolerance. For people with high caffeine tolerance, 160mg of caffeine in a day won’t be an issue.

But if you’re sensitive towards caffeine, 160mg might leave you feeling hot flushes.

A photo of coffee beans
Caffeine can mess with your sleep schedule if you consume too much.

The European Food Safety Authority (EFSA) recommends a maximum of 400mg of caffeine in a single day. And consumption of 200mg caffeine in one sitting.

Consuming more than 400mg of caffeine in a day might lead to specific health effects like:

  • Anxiety
  • Nervousness
  • Insomnia
  • Headaches
  • Shakiness, etc.

I like my energy drinks to have about 50-100mg of caffeine in a single serving. I don’t usually go for strongly caffeinated energy drinks unless I need the extra boost of energy.

If you have any pre-existing medical issues, please consult your doctor before drinking Relentless or any energy drinks.

How Much Sugar Is In Relentless?

Relentless has 24g of sugar in each 500ml cans.

The National Health Service UK (NHS) has declared to consume a maximum of 30g of free sugars in a day.

You might be wondering what “free sugar” might be; free sugar is the added sugar you mix with something already sweetened, such as chocolates, energy drinks, soft drinks, cakes, etc.

Having 30g sugar as our maximum daily intake, Relentless has 24g. Meaning you only have 6g of sugar left from your daily intake.

Overconsumption of sugar may lead to side effects like:

  • Weight gain
  • Spike in blood pressure
  • Obesity
  • Diabetes
  • Kidney disease
  • Heart disease
  • Sugar crashes
  • Tooth decay
A photo of table sugar
Consuming too much sugar may cause fatigue sometimes.

Having said that, if the sugar content is too much for you, you can opt for the Relentless Zero flavour. The Relentless Zero flavour has no free sugar at all.

B vitamins In Relentless

B vitamins or vitamins, in general, can do wonders.

Relentless has been very specific about the B vitamins they use in their 500ml energy drinks.

Vitamins EmployedVitamins In Relentless (500ml)Tolerable Daily Intakes
Vitamin B3 (Niacin)16mg16/14mg (men and women)
Vitamin B5 (Pantothenic Acid)8.5mg5mg
Vitamin B12 (Cobalamin) 2.0 ug2.4 ug
Comparison between the B vitamins applied in Relentless vs their maximum regular intakes.

You probably noticed that the amount of B vitamins used in Relentless is above the daily intakes.

Consuming B vitamins more than the usual daily intake leads to a vitamin overdose at times. Consuming too many B vitamins is pretty useless; considering B vitamins are water-soluble, they’ll get flushed down out of your system.

Besides these, some benefits of B vitamins are:

  • Promotes better cell health
  • Stimulates better red blood cell production
  • Better eyesight
  • Better digestion
  • Better nerve function

How Much Calories Does Relentless Have?

Relentless has 108 calories in a 500ml can.

The NHS also recommends a maximum of 2,500-2,000 calories per day for men and women. Given this, even if you consider 2,000 calories a standard, 108 calories wouldn’t cause any significant harm.

If you’re on a low-calorie diet, 108 calories shouldn’t put a dent in your diet unless the calorie count of your diet is meagre.

Relentless Vs Red Bull


The price of Relentless is £2 each can whereas Red Bull’s price is £2. These are the prices of the energy drinks minus the shipping charges.


Relentless has 160mg of caffeine, whereas Red Bull only has 80mg of caffeine per can. The caffeine content of Red Bull is similar to the caffeine of an average cup of coffee.


Relentless has 24g sugar in a 500ml can, and Red Bull has 27g sugar. I would say, both Relentless and Red Bull has high sugar content.

Relentless Vs Monster


Relentless costs £2, while Monster costs £2.


Monster has 179mg of caffeine, and Relentless has 160mg of caffeine.

Fortunately, both Monster and Relentless has less than the EFSA’s intake for 200mg caffeine per serving.


Relentless has 24g sugar, with Monster has a whopping 54g sugar.

For sugar wise, Relentless takes the win for being under the 30g sugar intake, whereas Monster’s sugar content is almost twice the daily recommended sugar content.

Benefits Of Relentless

There are many benefits Relentless is offering, some of which may include:

  • Feeling refreshed
  • Feeling energized
  • Enhanced athletic performance
  • Increased focus
  • Enhanced stamina
A photo of a girl drinking.
While the benefits may sound enticing, they are most noticeable when consumed in moderation.

Does Relentless Have Any Side Effects?

Relentless energy drink doesn’t have any significant side effects unless you’re going overboard with your consumption.

Overconsumption of Relentless may have side effects like:

  • Feeling nauseous
  • Sudden headaches
  • Upset stomach
  • Dizziness
  • Caffeine addiction
  • Caffeine crash
  • Sugar crash
  • Lack of sleep

How Many Relentless Energy Drinks Should You Drink In A Day?

If you drink Relentless every day or planning to, try drinking one can of Relentless energy drink every day.

I recommend one can because of the caffeine and sugar content.

Relentless has 160mg of caffeine in a single serving.

Drinking more than one can of Relentless will have a toll on your sleep schedule, whether you’re used to high caffeine content or not. This study shows how caffeine may affect your overall sleep performance.

Secondly, Relentless has a 24g sugar content. Drinking more than one can cause sugar side effects.

Can You Drink Relentless Energy Drink Every Day?

You can drink Relentless energy drinks every day.

Energy drinks work best when consumed regularly. One of the side effects of energy drinks is dulling your brain and causing sleep troubles.

If you start with Relentless, I recommend drinking half a can first and notice how your body reacts to the caffeine and sugar.

If you believe your body can handle it, consume the entire can. For health reasons, don’t consume more than one can of Relentless per day.

If you drink Relentless regularly, try it in the morning before your morning jog or workout for the best results.

If you drink it in the afternoon or later in the day, the caffeine in the drink will keep you awake and eventually cause you to sleep later than usual.

If you’re more curious about Relentless, check out this video review on the energy drink.

How much Relentless Energy drink is safe per week?

The safe consumption of Relentless Energy Drink per week depends on various factors, including age, health status, and individual tolerance to caffeine and stimulants. As a general guideline, it is recommended to limit intake to no more than one can of Relentless Energy Drink per day.

However, it’s important to note that consuming energy drinks, including Relentless Energy Drink, should not be considered a regular or necessary part of a healthy diet. It’s best to prioritize obtaining energy from natural sources such as a balanced diet, adequate hydration, and sufficient sleep.

Is it OK to drink Relentless Energy on an empty stomach?

It is not OK to drink Relentless Energy on an empty stomach. Consuming energy drinks on an empty stomach can result in a faster absorption of caffeine, leading to a more rapid and potentially higher spike in blood caffeine levels.

Moreover, consuming Relentless Energy Drink on an empty stomach may also lead to a higher risk of experiencing symptoms such as jitteriness, anxiety, and stomach upset. It’s best to consume Relentless Energy Drink with foo to help mitigate the potential negative effects on an empty stomach.

What happens if you drink energy drinks regularly?

Regular consumption of energy drinks can lead to several potential health issues. High caffeine intake can result in increased heart rate, high blood pressure, and sleep disturbances. Excessive sugar intake may contribute to weight gain and metabolic problems. Long-term use can also lead to caffeine dependency.

Furthermore, frequent consumption might affect hydration levels due to the diuretic effect of caffeine. The combination of caffeine, sugar, and other stimulants can have a negative impact on overall health. Moderation and considering alternative sources of energy, such as proper nutrition, hydration, exercise, and sufficient sleep, are important for maintaining well-being.

How many times can I drink energy drink a day?

The recommended frequency for consuming energy drinks varies based on factors like individual tolerance, caffeine sensitivity, and health status. Generally, limiting consumption to one energy drink per day is advisable to avoid excessive caffeine intake and potential side effects.

Monitoring your total caffeine intake from all sources, considering your daily activities, and paying attention to your body’s response are crucial. Opting for lower-caffeine or caffeine-free alternatives, staying hydrated, and maintaining a balanced diet can complement responsible energy drink consumption.

What Are The Flavours Of Relentless?

Relentless offers a variety of 7 different flavours. All of which include:

  • Origin
  • Zero (sugar-free version)
  • Cherry
  • Mango
  • Lemon Ice
  • Passion Punch
  • Apple Kiwi

Apart from the original and sugar-free flavours, most of them have a kick of fruity flavour in them.

Alternatives To Relentless

Here is a shortlist of other energy drinks you try other than Relentless:

Are you worried about the aftermath of too much sugar in Relentless? Check out my article on the best energy drinks without any crashes or ugly aftertaste.

Final Roundup

Let’s start with the caffeine and sugar contents; with 160mg of caffeine and 24g sugar, the drink will give you that extra energy boost and enhanced focus.

The calorie count is 108, which I don’t think is much unless you’re on a low-calorie diet.

For a price tag of £2, I personally think Relentless is a pretty decent energy drink, especially on the days when you’ll need to stay awake during the shifts or study sessions and need to focus.

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