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

The primary purpose of the research is to evaluate in healthy adults the time course effects of energy drink formulas containing 120 mg caffeine with varying levels of taurine and b vitamins on subjective alertness in the presence of cognitive load assessed hourly up to 5 hours post dose

Study Overview

• Status: Recruiting
• Conditions: Alertness
• Intervention / Treatment: Other: Flavored carbonated beverage, color-matched; Other: All beverages are flavor and color matched

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Crystal Haskell-Ramsay, PhD; Phone Number: (44) 191 2048818; Email: crystal.haskell-ramsay@northumbria.ac.uk

Study Locations

• United Kingdom
  • Tyne
    • Newcastle, Tyne, United Kingdom, NE1 7RU
      • Recruiting
      • Northumbria U
      • Contact: Crystal Haskell-Ramsay, PhD; Phone Number: (44) 191 2048818; Email: crystal.haskell-ramsay@northumbria.ac.uk
      • Contact: Philippa Jackson, PhD; Email: philippa.jackson@northumbria.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Participants are aged 18-49 years, inclusive
• Participants self-report that they are in good health
• Willing to maintain habitual diet, physical activity pattern, and body weight throughout the trial
• Willing to abstain from consumption of caffeine for 12 h prior to testing
• Willing to abstain from alcohol consumption and avoid vigorous physical activity for 24 h prior to all test visits
• Willing to refrain from 'over the counter' medications (e.g. pain medication) and stimulant medication for 12 hours, seasonal allergy/hayfever nasal antihistamine medications for 24 hours and oral antihistamines for 48 hours prior to all test visits
• Regular caffeine consumer (at least one caffeinated beverage per day, not less than 35 mg)
• Are fluent in English (equivalent to IELTS Level 6)
• Understand the study procedures and willing to provide informed consent to participate in the study and authorization to release relevant protected health information to the study Investigator

Exclusion Criteria:

• Fail to meet any one of the inclusion criteria
• Currently use of prescription medication, including contraceptives
• Report hypersensitivity to caffeine
• Have experienced major trauma or major surgical event within 6 months of screening
• Have extreme dietary habits, as judged by the Investigator (high fat, very high protein diets, intermittent fasting, etc.)
• Have a history of cancer in the prior two years, except for non-melanoma skin cancer
• Have a visual impairment that cannot be corrected with glasses or contact lenses
• Have food allergies/intolerances/sensitivities to any ingredients in the study products (including coffee or related foods/beverages/products)
• Self-report excessive leisure time physical activity (> 7 strenuous bouts per week)
• Have current or chronic gastrointestinal, sleep, or psychiatric disorders
• Work night shifts or follow a variable work pattern that results in irregular sleep pattern
• Are pregnant, trying to get pregnant or lactating
• Smoke tobacco, vape nicotine or use nicotine replacement products
• Use illegal/recreational drugs
• Are unable to demonstrate adequate minimal performance on lab, computer-based cognitive tasks
• Have high blood pressure (systolic over 139 mm Hg or diastolic over 89 mm Hg)
• Have a Body Mass Index (BMI) outside of the range 18.5-35 kg/m2 (unless waist to hip ratio is less than or equal to 0.85 (female) or 0.90 (male))
• Have been diagnosed with a neurological condition, or assessed as having a learning/behavioural or neurodevelopmental difference (e.g. dyslexia, autism, ADHD)
• Consume excessive caffeine intake (>400 mg per day)
• Have taken any dietary supplements e.g. Vitamins, omega 3 fish oils etc. in the last 4 weeks (Note: participation is possible following a 4 week supplement washout prior to participating and for the duration of the study on the proviso that the supplements they are taking are out of choice and not medically prescribed or advised)
• Have any health condition that would prevent fulfilment of the study requirements (this includes non-diagnosed conditions for which no medication may be taken)
• Have been diagnosed with/ undergoing treatment for alcohol or drug abuse in the last 12 months
• Have been diagnosed with/ undergoing treatment for a psychiatric disorder in the last 12 months
• Suffer from frequent migraines that require medication (more than or equal to 1 per month)
• Have any known active infections
• Do not have a bank account (required for payment)
• Have participated in another clinical trial within past 30 days and/or participation in another PepsiCo trial in the past 6 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo beverage; Base carbonated beverage with no caffeine, taurine, or vitamins	Other: Flavored carbonated beverage, color-matched; Base with 0 mg caffeine, taurine, vitamins
Experimental: Caffeine 120 mg beverage 1; Carbonated beverage with varying levels of taurine and B vitamins	Other: All beverages are flavor and color matched; Caffeine with varying amounts of taurine and B vitamins
Experimental: Caffeine 120 mg beverage 2; Carbonated beverage with varying levels of taurine and B vitamins	Other: All beverages are flavor and color matched; Caffeine with varying amounts of taurine and B vitamins
Experimental: Caffeine 120 mg beverage 3; Carbonated beverage with varying levels of taurine and B vitamins	Other: All beverages are flavor and color matched; Caffeine with varying amounts of taurine and B vitamins

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Caffeine Research Visual Analog Scale (VAS) subjective alertness factor adapted from Rogers et al.	Subjective 'alert' and 'tired' ratings combined to create a composite alertness factor. Alert ratings assessed by placing an 'x' on a line representing 0-100 to match their current state; tired ratings assessed by placing an 'x' on a line representing 0-100 to match their current state. Higher alert ratings represent a better outcome, higher tired ratings represent a worse outcome and are reversed to create the composite score, which is the average of the two scales and is scored 0-100 with higher scores representing a better outcome.	Change from baseline Time 0 to 240 minutes post-dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Simple reaction time	Cognitive function - attention measured as reaction time (in milliseconds), with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Digit vigilance accuracy	Cognitive function - attention measured as a percentage, with a higher score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Digit vigilance reaction time	Cognitive function - attention measured as reaction time (in milliseconds), with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Digit vigilance false alarms	Cognitive function - attention measured as number of errors, with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Choice reaction accuracy (%)	Cognitive function - attention measured as a percentage, with a higher score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Choice reaction accuracy (milliseconds)	Cognitive function - attention measured as reaction time (in milliseconds), with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Rapid visual information processing accuracy	Cognitive function - attention measured as a percentage, with a higher score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Rapid visual information processing reaction time	Cognitive function - attention measured as reaction time (in milliseconds), with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Rapid visual information processing false alarms	Cognitive function - attention measured as number of errors, with a lower score indicating better performance using the Computerised Mental Performance Assessment System (COMPASS)	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose. Each test has duration ~21 minutes )
Caffeine Research VAS measures (Visual Analog Scale) subjective tension factor adapted from Rogers et al.	Subjective 'relaxed' and 'tense' ratings combined to create a composite tension factor. Relaxed ratings assessed by placing an 'x' on a line representing 0-100 to match their current state; tense ratings assessed by placing an 'x' on a line representing 0-100 to match their current state. Higher tense ratings represent a worse outcome, higher relaxed ratings represent a better outcome and are reversed to create the composite score, which is the average of the two scales and is scored 0-100 with higher scores representing a worse outcome.	Change from baseline Time 0 to 60, 120, 180, 240 & 300 minutes post-dose

Collaborators and Investigators

• Sponsor: PepsiCo Global R&D
• Investigators: Principal Investigator: Crystal Haskell-Ramsay, PhD, Northumbria U Newcastle, UK

Study record dates

Study Major Dates

• Study Start (Actual): January 26, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): August 30, 2026

Study Registration Dates

• First Submitted: February 3, 2026
• First Submitted That Met QC Criteria: February 3, 2026
• First Posted (Actual): February 10, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: caffeine; energy; beverage; alertness
• Other Study ID Numbers: PEP-2514

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No