RecruitingNAINTERVENTIONAL

Evaluating the Impact of Energy Drink Formulas on Alertness for an Extended Period

This research wants to understand how different energy drink recipes affect how alert healthy adults feel. All the drinks will contain 120mg of caffeine, but with varying levels of taurine and B vitamins. Participants will drink one of these specially prepared beverages, which are matched in flavour and colour, and then their alertness will be checked every hour for up to five hours afterwards. The study is designed to see if these energy drink ingredients make a difference to how people feel when they are doing tasks that require concentration. It's for adults aged 18 to 49 who are generally healthy and regularly consume caffeine.

At a glance

Status

Recruiting

Phase

Sponsor

PepsiCo Global R&D

Enrolment target

Start

26 Jan 2026

Estimated completion

30 Aug 2026

Alertness

What is this study about?

This study aims to discover how different combinations of ingredients in energy drinks affect how awake and focused people feel. Specifically, researchers are testing drinks that all contain 120mg of caffeine, similar to a standard cup of coffee, but with varying amounts of taurine (an amino acid often found in energy drinks) and B vitamins. They want to see if these variations make a difference to a person's alertness over several hours.

The idea is to get a clearer picture of whether these popular energy drink ingredients truly help with alertness, especially during tasks that require a lot of mental effort. Participants will be given one of these specially prepared drinks, which are designed to look and taste the same, and then their feelings of alertness will be carefully monitored every hour for up to five hours.

By comparing how different groups of people react to these slightly different drinks, the researchers hope to learn more about the science behind energy drinks and their effects. This information could be useful for understanding how these beverages work and who might benefit most from them.

Key takeaways

The study explores how different energy drink ingredients affect alertness.
It focuses on healthy adults aged 18-49 who regularly consume caffeine.
Participants will drink test beverages and have their alertness monitored for up to 5 hours.
The drinks contain caffeine, taurine, and B vitamins, but are flavour and colour matched.
It requires temporarily avoiding caffeine, alcohol, and certain medications before visits.

Who may be eligible?

To join this study, you need to be a healthy adult between 18 and 49 years old. You should generally feel well and be a regular caffeine drinker, having at least one caffeinated drink every day. You'll also need to be able to understand study instructions in English and give your consent to take part.

There are several reasons why you might not be able to join. For example, if you are currently taking any prescription medication, including contraceptives, or if you have certain health conditions like stomach problems, sleep disorders, or mental health issues. If you've had major surgery recently, have certain eye problems, or have allergies to any ingredients found in the study drinks (like coffee), you wouldn't be able to participate.

You also can't take part if you are pregnant, trying to get pregnant, or if you work night shifts or have a very irregular sleep pattern. The study needs participants who can stick to a regular routine during the trial and avoid certain activities or medications before visits.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 49 years old?
Do you feel generally healthy?
Do you drink at least one caffeinated beverage daily?
Are you able to speak and understand English well?
Are you currently NOT taking any prescription medications (including contraception)?
Do you NOT have stomach problems, sleep disorders, or mental health conditions?

Answer every question to see your result.

What does participation involve?

If you join this study, you will need to attend several visits at the study site. Before each visit, you'll be asked to avoid caffeine for 12 hours, alcohol and vigorous exercise for 24 hours, and certain over-the-counter medications for differing lengths of time (12-48 hours depending on the type). During each visit, you'll drink a test beverage, which is specially made to look and taste the same as others in the study, and then perform tasks that test your mental focus. Your alertness will be assessed hourly for up to five hours after drinking the beverage. You'll also be asked to maintain your usual diet, exercise, and body weight throughout the study. The total duration of your involvement will depend on the number of study visits required.

Potential risks and benefits

Participating in research studies like this can help advance our understanding of how ingredients in energy drinks affect the body. While there's no direct personal benefit promised for taking part, your contribution could help others in the future. The risks involve the potential for mild effects from the caffeine, such as temporary jitters or trouble sleeping, especially if you are sensitive to it. You will be asked to abstain from caffeine before visits, which might cause temporary withdrawal symptoms like headaches in regular users. You are free to withdraw from the study at any time, for any reason, without needing to explain why, and it will not affect any medical care you receive.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Northumbria U
Verified postcode
Newcastle, United Kingdom· Recruiting

Common questions

What kind of drinks will I be given?

You will be given specially prepared carbonated soft drinks that all contain 120mg of caffeine. They will all taste and look the same, but will have varying amounts of taurine and B vitamins to test their effects.

How long will I need to be at the study centre for each visit?

On each study visit, your alertness will be checked hourly for up to five hours after you drink the test beverage, so plan for at least this amount of time at the centre.

Will I know if I'm getting a drink with more or less taurine?

No, the drinks are designed to be indistinguishable in taste and colour, and neither you nor the researchers will know which specific formula you are receiving at the time of your visit. This helps ensure unbiased results.

Do I have to stop all my medications to participate?

You cannot be taking any prescription medications, including contraceptives. For over-the-counter medications, you'll need to stop taking them for 12 to 48 hours before each visit, depending on the type of medication.

What does 'cognitive load' mean in this study?

Cognitive load refers to mental tasks or activities that require focus and concentration. In the study, you'll be doing these kinds of tasks to see how the energy drinks affect your ability to stay alert while thinking hard.

How to find out more

Crystal Haskell-Ramsay, PhD

crystal.haskell-ramsay@northumbria.ac.uk (44) 191 2048818 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.