The primary purpose of this study is to evaluate the impact of a polyherbal dietary supplement (Designs for Health - GlucoSupreme™ Herbal) on markers of glycemic control and other structure/function outcomes among a sample of prediabetic adults.

A 12-week randomized, double-blinded, placebo-controlled clinical trial will be conducted to achieve the purpose of this study. The research team hypothesizes that GlucoSupreme™ Herbal will improve a variety of validated markers of glycemic control that are commonly used in clinical practice more effectively than placebo.

Prediabetes is a common state in which blood glucose levels are elevated, but are not elevated high enough to be considered Type 2 Diabetes (T2D). The worldwide prevalence of prediabetes is high and rapidly increasing. People with prediabetes are at increased risk for developing a variety of chronic diseases. Most notably, prediabetes nearly always precedes diagnosis of T2D, a poorly-controlled disease adversely affecting 14% of adults in the United States. T2D is responsible for increased risk of heart disease, stroke, blindness and other vision problems, kidney disease, amputations and death. Prediabetes often progresses to T2D relatively quickly, as pancreatic beta-cell dysfunction perpetuates. There are currently limited pharmacological options available for safely reducing the burden of prediabetes. Furthermore, these pharmacological options often carry potentially deleterious side effects. Low-risk alternatives are needed where lifestyle modifications, such as increased physical activity and weight loss, have failed.

Herbal dietary supplements have shown promise in safely managing impaired glycemic control in prediabetic adults in many clinical studies. A wide variety of herbs have been previously studied for these purposes, including cinnamon, fenugreek, banaba, curcumin, and a variety of combination products. Of these, most have demonstrated improved management of glycemic control, particularly with regard to reducing fasting blood glucose and postprandial glucose, HbA1c, fasting insulin levels, HOMA-Insulin Resistance, and increasing HOMA-β cell function among prediabetic adult populations. Many herbs have also demonstrated benefit in the management of glycemic control in clinical trials among T2D populations. These herbs include berberine, ginseng, gymnema, banaba, cinnamon, fenugreek, and kudzu, all of which are present in GlucoSupreme™ Herbal.

The research team hypothesizes that GlucoSupreme™ Herbal will demonstrate superior improvements in markers of glycemic control than placebo over twelve weeks of daily supplementation among a sample of healthy adults. The research team aims to conduct a randomized, placebo-controlled, double-blinded clinical trial to evaluate this hypothesis among a diverse sample of 40 prediabetic adults, and will implement a 1:1 study allocation ratio. This study will utilize an adaptive sample size re-estimation (SSR) approach where participant enrollment may be extended beyond the originally planned sample size if interim effect size is smaller than anticipated, but still promising, thereby preserving study power; this will be determined by examination of available unblinded endpoint data by an independent statistician after 30 subjects are enrolled.

Inclusion Criteria:

1. Age ≥ 18 years
2. Prediabetic blood measurement (HbA1C) of 5.7-6.4% and/or fasting blood glucose of 100-125 mg/dl and/or 2-hour Oral Glucose Tolerance Test blood glucose value of 140 mg/dl-199 mg/dl1 2) taken within the last 12 weeks
3. Agree to continue with current diet and refrain from taking any new nutritional or herbal supplements
4. Able to understand and write English
5. Voluntarily consent to the study and understand its nature and purpose including potential risks and side effects

Exclusion Criteria:

1. Current daily use of any oral hypoglycemic medication or insulin injection
2. Current daily use of any supplement containing the herbs in the study supplement
3. Known allergies to any substance in the study supplement
4. Current daily tobacco smoker
5. Currently pregnant or planning to become pregnant in the next 12 weeks
6. Any current or previous diagnosis of diabetes (Type 1 or Type 2)
7. Myocardial infarction, vascular surgery, or stroke in the past year

The study products will be delivered to the investigative sites prior to enrollment of subjects. A study code will be provided for every batch of study product shipped to the investigational site prior to the beginning of the study. The placebo utilized in this clinical trial will be formulated to be as similar as possible to the active in appearance, odor, and other key characteristics, and packaging for both intervention and placebo will be the same. The de-identified study product will be packaged and labeled according to the study code and participant identification numbers; the Study Coordinator will oversee a locked master list of these, in addition to batch numbers.