Your participation in this study will be over approximately 3 week for each Arm. You may choose to participate in just Arm 1, or Arm 2, or if your availability suits, you could participate in both.

Each study Arm comprises of a full day where you will take the supplement combination, followed by either 1 (Arm 1) or 2 (Arm 2) mornings where a follow up blood sample will be taken. There will then be a 2 week break, before the process of full day followed by 1 (Arm 1) or 2 (Arm 2) mornings will be repeated. The morning visits are anticipated to take approximately 20-30 minutes.

Arm 1 (Vitamin D3 + K2) Dates :

Group 1

Round 1

• Tuesday 9th December – approximately 11 hrs from 6.30am to approximately 5.30pm
• Wednesday 10th December – 30 mins between 7am-9am
• Thursday 11th December – 30 mins between 7am-9am

Round 2

• Tuesday 13th January 2026 – approximately 11 hrs from 6.30am to approximately 5.30pm
• Wednesday 14th January 2026 – 30 mins between 7am-9am
• Thursday 15th January 2026 – 30 mins between 7am-9am

Group 2

Round 1

• Tuesday 13th January – approximately 11 hrs from 6.30am to approximately 5.30pm
• Wednesday 14th January – 30 mins between 7am-9am
• Thursday 15th January – 30 mins between 7am-9am

Round 2

• Tuesday 27th January 2026 – approximately 11 hrs from 6.30am to approximately 5.30pm
• Wednesday 28th January 2026 – 30 mins between 7am-9am
• Thursday 29th January 2026 – 30 mins between 7am-9am

You will need to attend both study rounds for your chosen group. 

Arm 2 (Glutathione + PQQ combination) Dates :

Round 1

• Thursday 8th January 2026 – approximately 9hrs from 7am to approximately 4pm
• Friday 9th January 2026 – 30 mins between 7am-9am

Round 2

• Thursday 22nd January 2026 – approximately 9hrs from 7am to approximately 4pm
• Friday 23rd January 2026 – 30 mins between 7am-9am

You will need to attend both study rounds.

We will confirm the specific dates and duration of your clinic visits during your initial phone screening.

All requirements of the study will be completed during your clinic visits. There are no overnight stays required and you will not be required to take any study product at home.

Please see below for more information. You can also register your interest using the form at the bottom of this page.

We will be testing two different supplement combinations:

ARM 1: Vitamin D3 + K2 combination – liposomal formulation vs standard comparator

ARM 2: Glutathione + PQQ combination – liposomal formulation vs standard comparator

The supplements being tested contain nutrients that are important for various aspects of health:

• Vitamin D3 is essential for bone health, immune function, and overall wellbeing
• Vitamin K2 works with Vitamin D3 to support bone and cardiovascular health
• Glutathione is a powerful antioxidant that supports cellular health and detoxification
• PQQ (Pyrroloquinoline quinone) supports cellular energy production and brain health

The products will be supplied in capsule form, and participants will be required to take the allocated study product at the beginning of each full day study visit.

This study uses a double-blind, crossover design, meaning for each Arm you participate in, you will receive both the liposomal version and the standard version, but neither you nor the investigators will know which product you are receiving at each visit. However, this information will be available to you upon completion of the study or at any time if it is necessary for your care. This design helps ensure that the results are not influenced by expectations about which product might work better.

During the study, you will be asked to:

• Attend our clinic 2 times for full-day visits
• Fast for 10 hours before each full-day clinic visit (water is ok)
• Take the study product (as a capsule) once at the beginning of each full-day visit
• Have blood draws taken throughout each full-day visit (via a cannula in your arm)
• Attend follow up appointment for a single needle draw (4 visits for Arm 1 and 2 visits for Arm 2)

There are no overnight stays required in this study, nor will you be required to take study product at home between visits.

During each full-day visit, you will be provided with food and snacks, and you are welcome to bring your own device to pass the time. Please note that not all diets will be able to be catered to. If you do require a specific diet, please let us know at the time of screening. If you are planning to use your device, we do ask that participants to bring headphones so as not to disturb other participants.

Study Schedule

 If you are eligible to enrol in this study, you can participate in Arm 1, or Arm 2, or both.

Arm 1: Vitamin D3 + K2:

6 clinic visits over approximately 3 weeks

• Visit 1: 11-hour clinic visit (Dosing and Absorption Assessment)
• Return home after Visit 1 and return the following morning

• Visit 2: 30-minute visit (24-hour follow-up blood draw)
• Return home after Visit 2 and return the following morning

• Visit 3: 30-minute visit (48-hour follow-up blood draw)
• Return home after Visit 3

***Minimum of 2-week washout period***

• Visit 4: 11-hour visit (Dosing and Absorption Assessment)
• Return home after Visit 4 and return the following morning

• Visit 5: 30-minute visit (24-hour follow-up blood draw)
• Return home after Visit 5 and return the following morning

• Visit 6: 30-minute visit (48-hour follow-up blood draw)
• Return home after Visit 6

***Participation in Arm 1 concludes***

Arm 2: Glutathione + PQQ:

4 clinic visits over approximately 3 weeks

• Visit 1: 9-hour clinic visit (Dosing and Absorption Assessment)
• Return home after Visit 1 and return the following morning

• Visit 2: 30-minute visit (24-hour follow-up blood draw)
• Return home after Visit 2

***Minimum of 2-week washout period***

• Visit 3: 9-hour clinic visit (Dosing and Absorption Assessment)
• Return home after Visit 3 and return the following morning

• Visit 4: 30-munute visit (24-hour follow-up blood draw)
• Return home after Visit 4

***Participation in Arm 2 concludes***

Please note: This page is a summary of the study outline and participant requirements. A full Participant Information Sheet with detailed information will be provided to you before you are asked to give your consent to participate.

Upon completion of the study requirements, you will be eligible for payment for your time and travel expenses (the amount will depend on what study arms you have participated in).

• Arm 1: Vitamin D3 + K2 Supplement – Total reimbursement $600
• Arm 2: Glutathione + PQQ Supplement – Total reimbursement $500

The payment will be made by gift voucher or via direct deposit to your nominated bank account (your choice) once all study requirements have been met. Please note, that as payment needs to be processed after your completion and via our payment portal, please allow 5-7 business days after completion to receive payment.

Pro rata payments will be made in the case of early withdrawal as detailed in the participant information sheet that will be provided to you.

If you are interested in participating, we’d love to hear from you. Please register your interest by answering the questionnaire and completing the form on this page…we’ll then get in touch to screen you for eligibility.

Our clinic is centrally located on Level 3, 252 St Pauls Terrace, Fortitude Valley.

Due to limited availability, there will not be on-site parking provided for this study. However, our clinic is a 10 minute walk from Fortitude Valley train station, and there are multiple bus stops within close proximity.

• Adults 18-50 years old
• BMI between 18.5 and 30.0 kg/m² (you can check your BMI using the calculator below)
• Generally healthy
• Able to provide informed consent
• Able to commit to completing the study requirements
• Able to fast for 10 hours prior to study visits
• No prior issues with providing blood samples

BMI Calculator

This study has been approved by the University of Queensland Human Research Ethics Committee under Approval Number: 2025/HE001712. The study is also registered on the clinicaltrials.gov under Registration Number: ISRCTN39055102

Trained trial coordinators will supervise your progress throughout the study. Your results will be made available to you at the conclusion of the study. Any of your personal information collected during the study will be kept in the strictest confidence.