Best Evidence Analyses and Commentary

Does natural supplement Glucocil live up to the hype?
Alan Sawatsky, PharmD Candidate 2012

Dietary supplements present a unique challenge to practitioners.  These loosely- regulated, over-the-counter products are widely advertised towards the general public, yet these products are not held to the same FDA standards as prescription medications in terms of having to provide proof of their safety and efficacy.  Glucocil™ is one such recent dietary supplement intended to help manage type II diabetes.  It has been seen heavily advertised via various media outlets, including Facebook® and Google®.  The product is promoted by the manufacturer to “help type 2 diabetics:  stabilize fasting and post-meal blood sugar levels, promote heart, blood vessel, and circulatory health, contribute to weight management, and maintain healthy nerve function.”[1]

The primary listed ingredient per the product website is mulberry leaf extract (not to be confused with Indian mulberry, a primary component of the widely distributed Noni juice).  Scant research is currently available on this component, with most of the research available being studies performed on rats.  A small study (sample size of 10 healthy control subjects and 10 type II diabetics) on humans published in 2007 demonstrated significant reduction in blood glucose increase within the first 120 minutes following ingestion of sucrose in patients taking mulberry extract vs. placebo.  The mean increases in serum glucose in healthy patients were found to be 15 vs. 22 mg/dL for mulberry vs. placebo, respectively, and mean increases in serum glucose in type II diabetics were 42 vs. 54 mg/dL for mulberry vs. placebo, respectively.[2]   These results show some promise, but the clinical impact of such a small trial is unclear.  A larger, randomized controlled trial in Korea is in the planning phases as of February 2011, but there is an indefinite time period awaiting the publication of the results of that trial.[3]

The remainder of the ingredients and their respective efficacy for management of type II diabetes are listed below.  An explanation of Natural Standard’s grading system can be found here.

Listed Ingredient

Evidence Level for Diabetes (per Natural Standard)[4]

Mulberry Leaf Extract

No rating per Natural Standard

Alpha Lipoic Acid


Banaba Leaf Extract


Chromium Picolinate


Cinnamon Bark Powder


Fish Oil


Gymnema Sylvestre Extract


Insulina Leaf Extract

Ingredient not listed on Natural Standard

Veld Grape Stem Extract

Ingredient not listed on Natural Standard

Vitamins B1, B6, B12


Vitamin D



Additionally, the NIH National Center for Complementary and Alternative Medicine concurs that alpha lipoic acid may have a glucose lowering effect, and that the remainder of the ingredients have insufficient evidence supporting their efficacy.[5]   It is clear that a majority of the listed ingredients for this product have unclear or insufficient evidence for the treatment of type II diabetes.  It is important to note also that the ingredients listed above are categorized on the package label as a proprietary “Glucocil™ Blood Glucose Management Blend”[1] , and the specific quantity of each ingredient remains unspecified.  Even if some of the above ingredients do have some clinical evidence supporting their use, it is impossible to determine whether or not sufficient levels of those ingredients are present in Glucocil™’s proprietary blend. 

At this time there is not sufficient evidence to support the supplemental use of Glucocil™ in the management of type II diabetes until further evidence is published to establish its efficacy and safety in the general population.  Patients considering this product should be advised regarding the lack of evidence supporting its efficacy, and the lack of regulation of dietary supplements in general.  However, if patients are taking or wish to begin taking this product, they should be sure to inform their doctor to ensure that none of the ingredients pose any health risk considering other concurrent disease states.


1.       Natural Glucocil:  The All-Day Glucose Stabilizer.  Product website; Found at:  Accessed 31 August 2011.

2.       Mudra M, et al.  Influence of mulberry leaf extract on the blood glucose and breath hydrogen response to ingestion of 75 g sucrose by type 2 diabetic and control subjects.  Diabetes Care. 2007 May;30(5):1272-4.  Found at:  Accessed 31 August 2011.

3.       Park S, et al.  The efficacy and safety study of dietary supplement PURIAM110 on non-insulin taking Korean adults in the stage of pre-diabetes and diabetes mellitus: protocol for a randomized, double-blind, placebo-controlled, and multicenter trial-pilot study.  Trials. 2011 Feb 11;12:38.  Found at:  Accessed 30 August 2011.

4.       Natural Standard:  The Authority on Integrated Medicine, official website; Found at:  Accessed 31 August 2011.

5.       National Center for Complementary and Alternative Medicine.  Diabetes and CAM:  A Focus on Dietary Supplements.  Found at:  Accessed 06 September 2011.

Website Terms of Use Disclaimer | E-mail Terms of Use | Contact LECOM | RSS | Copyright © 2009 LECOM - All rights reserved