Psychological Effects of 8 Weeks Supplementation With Sceletium Tortuosum Extract

Psychological Effects of 8 Weeks Supplementation With Sceletium Tortuosum Extract (Zembrin™): a Randomised, Double Blind, Placebo-controlled, Parallel-groups Trial

This study employs a randomized controlled trial to test the cognitive enhancing and stress relieving potential of the product Zembrin® in healthy adults when consumed over an 8 week period.

The aim of the proposed randomized, double-blind, placebo-controlled, parallel groups study is to assess the effects of 8 weeks supplementation with Zembrin®, in 30-50 year old healthy adults, on cognitive function, mood, psychological and physiological stress responses during a laboratory stressor, fatigue and sleep quality. The trial will utilize the COMPASS cognitive assessment system and a range of mood measures and will employ the Observed Multitasking Stressor (OMS), with psychological state and physiological responses assessed before and after, and cognitive function assessed during, the stressor. The cognitive/mood assessments will take place prior to (Day -1 with respect to treatment) and after 8 weeks supplementation with Zembrin. An interim mood/fatigue assessment will take place online (Cognimapp) with a baseline measurement collected between the screening visit and Day -1 and post dose measurements collected after 7 and 28 days 1 and 4 weeks of treatment.

Inclusion Criteria:

Participants must self-assess themselves as being in good health Aged 30 to 50 years at the time of giving consent

Exclusion Criteria:

Participants are not eligible to take part if they:

• Have any pre-existing medical condition/illness which will impact taking part in the study NOTE: the explicit exceptions to this are controlled hay fever, high cholesterol and reflux-related conditions. There may be other, unforeseen, exceptions and these will be considered on a case-by-case basis; i.e. participants may be allowed to progress to screening if they have a condition/illness which would not interact with the active treatments or impede performance.
• Are currently taking prescription medications NOTE: the explicit exceptions to this are contraceptive treatments for female participants, those medications used in the treatment of reflux-related conditions; and those taken 'as needed' in the treatment of asthma and hay fever. As above, there may be other instances of medication use which, where no interaction with the active treatments is likely, and which would not be expected to have any impact on brain function, participants may be able to progress to screening.
• Have high blood pressure (systolic over 159 mm Hg or diastolic over 99 mm Hg)
• Have a Body Mass Index (BMI) outside of the range 18.5-35 kg/m2
• Are pregnant, seeking to become pregnant or lactating.
• Are menopausal/post-menopausal
• 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
• Take any illicit social drugs, including cannabis
• Have excessive caffeine intake (>500 mg per day)
• Have relevant food intolerances/ sensitivities
• Have taken antibiotics within the past 4 weeks
• Have taken dietary supplements eg. Vitamins, omega 3 fish oils, herbal extracts, cannabadiol 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 taken are out of choice and 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
• Has 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
• Suffers from frequent migraines that require medication (more than or equal to 1 per month)
• Sleep disorders or are taking sleep aid medication
• Any known active infections
• Have oral disease
• Does not have a bank account (required for payment)
• Are non-compliant with regards treatment consumption