The proposed design is a randomised, double-blind, controlled, crossover intervention assessing the effects of an active intervention, containing Scutellaria baicalensis and Crataegus, versus placebo, on stress, cognition, sleep and wellbeing in healthy human volunteers. Outcome measures will be assessed acutely on day 1 and following 14 days of supplement consumption. Some interim outcome measures will also be assessed throughout the supplementation period to monitor sub-chronic changes

Participants will attend the laboratory on 5 occasions. The first visit will take place on day -2 (this is a minimum period and can take place a maximum of 14 days prior to the baseline lab visit. A training refresher will take place if 14 days is exceeded) and represents an in-person screening and training visit. (This takes place following an earlier telephone pre-screen where participants will confirm that they meet the study inclusion criteria, and not any of the exclusion criteria (performed separately, this refines the lab-based screening/training visit).) Here participants will provide written, informed consent, complete demographic and anthropometric measurements (BMI & WHR) and be trained on the COMPASS cognitive tasks and study questionnaires.

If progressed through training/screening, participants will then return to the lab, on day 1, to complete their baseline lab visit for arm 1. This will take place at approximately 10:00 am, with participants having consumed their normal breakfast no later than 8:30 am that morning. Participants will first complete the PROM questionnaires and a baseline GSR reading (including a day-baseline saliva sample) will also be taken during this time. For the next 50 minutes, participants will complete the pre-dose COMPASS cognitive task battery and, after a short break, participants will complete the pre-dose OMS. At approximately 11:50 am, participants will consume their full daily treatment dose (2 tablets) along with a standardised lunch of a white bread cheese sandwich, packet of ready salted crisps, and a custard pot. After an hour-long 'absorption' period, participants will complete the post-dose COMPASS cognitive tasks and OMS and the testing day will be completed at approximately 2:30 pm.

Before leaving the lab, participants will be provided with their 14 (+/- the additional doses required for compliance and in case of delayed return for the chronic visit) days-worth of treatment, alongside a treatment diary to note down the time of treatment consumption each day. (The number of returned tablets on day 15, alongside reference to this treatment diary, will serve as the study compliance measures.) Participants will be advised to adhere to the following dosing regimen for each day going forward; 1 tablet in the morning, 1 in the evening, to be consumed 1 hour away from meals. On day 7 (+/- 2 days), participants will complete the PROM questionnaires, via survey, at home.

Participants will return to the lab on day 15 (+/- 2 days), following 14 full days of treatment, for the chronic lab visit for arm 1, and repeat the same procedure as day 1. A minimum 14-day washout period (with a maximum of 28 days) will then commence.

On day 30, participants will return to the lab for the baseline visit for arm 2 and repeat the same procedure as the acute arm 1 for visit. During the interim period, treatment will be consumed in the same way and, half-way through the dosing period (day 36 (+/- 2 days)) participants will complete the PROM questionnaires, via survey, at home.

On day 44 (+/- 2 days) participants will return to the lab for the chronic lab visit for arm 2, their final visit, which will be identical to the arm 1 chronic lab visit, with the exception that participants will be debriefed at the end of their visit and participant payment arranged. Here, participants will also be asked which treatment order they believed themselves to be on.

Please see figure 3 for the overall trial diagram and figure 4 for the procedure within the acute and chronic testing sessions.

Inclusion Criteria:

• 18-75

Exclusion Criteria:

• • If participant scores less 12, or less, on the Perceived Stress Scale

  • Have any pre-existing medical condition/illness which will impact taking part in the study

    * NOTE: the explicit exceptions to this are controlled hyper/hypothyroidism, hay fever, high cholesterol and reflux-related conditions

  • Are currently taking prescription medications

    *NOTE: the explicit exceptions to this are contraceptive treatments for female participants, thyroid medications, topical skin treatments and those medications used in the treatment of high cholesterol and reflux-related conditions; and those taken 'as needed' in the treatment of asthma and hay fever

  • Have high blood pressure (systolic over 159 mm Hg or diastolic over 99 mm Hg). NOTE: that we must measure this in the lab using our blood pressure monitors and can only use our measurements to assess eligibility rather than home or GP readings

  • Have a Body Mass Index (BMI) outside of the range 18.5-35 kg/m2

  • Are pregnant, seeking to become pregnant or lactating

  • Have learning and/or behavioural difficulties such as dyslexia or ADHD

  • Have a visual impairment that cannot be corrected with glasses or contact lenses (including colour-blindness)

  • Smoke tobacco or vape nicotine or use nicotine replacement products (if you have recently quit smoking or using replacements you must have stopped using them altogether for a period of 3 months before participating in this study)

  • Have excessive caffeine intake (>500 mg per day). Note: This will be calculated at screening but feel free to query this with the researcher prior to attendance

  • Have relevant food allergies/ intolerances/ sensitivities (Please discuss with researcher prior to attendance if you are unsure of relevance)

  • Have taken antibiotics within the past 4 weeks

  • Have taken 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 are taken are out of choice and are not medically prescribed or advised). Existing and consistent use of vitamin D supplements and protein shakes are permitted

  • Have any health condition that would prevent fulfilment of the study requirements (this includes non-diagnosed conditions for which no medication may be taken)

  • Are unable to complete all of the study assessments

  • Are currently participating in other clinical or nutrition intervention studies, or have in the past 4 weeks

  • 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, including a medical diagnosis of anxiety or depression.

  • Suffers from frequent migraines that require medication (more than or equal to 1 per month)

  • Have oral disease

  • Have any known active infections

  • Does not have a bank account (required for payment)

  • Are non-compliant with regards treatment consumption

Pseudonymized and compiled data sheets only