Plant-based tonic drink for reducing post-meal blood sugar and insulin spikes

Examining the Efficacy of a Commercially Available Multi-ingredient Liquid Tonic Drink on Postprandial Glycemia in Men and Women With Overweight and/or Obesity.

Not applicable Interventional Australian Catholic University · NCT07030010

We will test whether drinking a plant-based tonic with a high-carbohydrate meal lowers post-meal blood sugar and insulin in adults who are overweight or obese.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment20 (estimated)
Ages30 Years to 64 Years
SexAll
SponsorAustralian Catholic University Academic / other
Locations1 site (Melbourne, Victoria)
Trial IDNCT07030010 on ClinicalTrials.gov

What this trial studies

This randomized, double-blind, placebo-controlled crossover study invites 20 adults with overweight or obesity to attend two laboratory visits at Australian Catholic University. On each visit participants will consume the same high-carbohydrate meal with either a plant-based tonic drink or a matching placebo, with the order randomized. Participants will remain in the lab for three hours after the meal with a venous cannula for repeated blood draws to measure glucose and appetite hormones; they will also wear a continuous glucose monitor over the period covering both visits. The crossover design means each person serves as their own control to compare postprandial glucose and insulin responses between the tonic and placebo.

Who should consider this trial

Good fit: Adults aged 30–64 years with a BMI of 27.0 kg/m2 or higher who are not pregnant or breastfeeding and can attend two in-person visits in Melbourne are ideal candidates.

Not a fit: People with diagnosed metabolic, endocrine, gastrointestinal, or cardiovascular diseases, those taking medications for blood glucose, pregnant or breastfeeding individuals, or those with BMI under 27 are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, the tonic could reduce post-meal glucose and insulin spikes and help improve metabolic control for people with overweight or obesity.

How similar studies have performed: Some prior small studies of plant-derived bitter compounds or tonics have shown modest reductions in postprandial glucose, but results are mixed and more controlled trials are needed.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Aged ≥30-64 years
* Body Mass Index (BMI) of ≥27.0 kg/m2

Exclusion Criteria:

* younger than 30 or 65 years or older,
* a BMI less than 27.0 kg/m2,
* have an allergy to any of the components in the plant-based tonic (see section 6),
* pregnant or breastfeeding,
* regularly skipping breakfast (i.e. not consuming breakfast on 5/7 days per week),
* any diagnosed metabolic (e.g. diabetes), endocrine (e.g. hyperthyroidism), gastrointestinal (e.g. Crohn's) or cardiovascular (e.g. heart failure) abnormalities,
* on an energy-restricted diet; significant weight fluctuation in the previous 3 months (\>5% body weight),
* high alcohol consumption (\>14 units/week) (as per Alcohol Drink Guidelines),
* medication that is used to treat blood glucose,
* unable to attend in person testing sessions, or
* unable or unwilling to provide blood samples.

Where this trial is running

Melbourne, Victoria

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Overweight or Obese AdultsPostprandial hormonesMixed meal challengeTonic drink
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.