Update July 23, 2013:
The FDA has sent the manufacturer of Glucocil a Warning Letter indicating that it is misbranded, and an unapproved new drug.
Recently, advertisements for an over-the-counter product with herbal, vitamin, and other ingredients that purports to control blood glucose have been popping up all over the place online. It's described as an "all day glucose stabilizer" (and they've trademarked that phrase).
The concoction consists of mulberry leaf extract, fish oil, Vitamins B1, B6, B12, and D, and a host of other ingredients, including many of the time-honored favorites of the snake-oil salesmen (because they do have a bit of effect on blood glucose): alpha-lipoic acid, Chromium Picolinate, cinnamon bark, and Gymnema Sylvestre. It also contains some stuff I hadn't heard of (Banaba Leaf, Berberine, Veld Grape Stem extract, etc.). The main pitch for the present concoction is the presence of mulberry leaves, which have "been used in Chinese traditional medicine for thousands of years [and] if taken often can make people wise and the body light and ageless; it can promote beauty and strength digestion, calm spirits and stabilize moods." Nothing there, by the way to hint that it can control glucose levels.
However, a brief report that was published in Diabetes Care Inï¬‚uence 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 does give a small amount of ammunition to the argument that mulberry leaf extract might do something worthwhile. In the study, 10 people with T2D and 10 controls were given "mulberry leaf extract" provided by NatureGen (San Diego, CA)" or placebo, together with 75 grams of sucrose in hot water. The subjects taking mulberry leaf extract were observed to have their BG go up less, and fall faster, when compared to what occurred when the same subjects took placebo. Apparently each subject participated twice: once getting MLE and once getting placebo. Side effects were not discussed other than the unhelpful comment that "3 of 20 subjects receiving mulberry or placebo reported mild gas and/or bloating."
Interestingly, one of the coauthors of this paper (Litao Zhong, MD, PhD) is listed as working for NatureGen, Inc, who supplied the MLE for the study. At another website, Dr. Lee Zhong is mentioned as President and Founder of Neuliven Health, which makes the present concoction. At LinkedIn, Lee Zhong is identified as president of NatureGen. And according to a trademark website, NatureGen, Inc., owns the trademark name Neuliven Health. Any surprise if I were to conclude that Lee and Litao are likely the same person, and that Neuliven and NatureGen are one and the same?
Back to my concern about the concoction. According to a press release, this combination of stuff is able to stabilize fasting and post-meal blood sugar levels, reduce absorption of sugars and other carbohydrates, increase insulin sensitivity and production, promote heart, blood vessel, and nerve health, and contribute to weight management. I don't see any evidence for any of these claims based on studies of the concoction itself. Or for that matter, I can't find any studies of the concoction. Each of these claims therefore must be based on separate studies of the ingredients, and whether the various ingredients work together synergistically, as the manufacturer obviously hopes, or in theory whether the ingredients actually oppose each other's actions, is impossible to say.
And the product's website claims (without any documentation that I can find) that the concoction's "ingredients help you" lower fasting blood sugar levels up to 29%, lower peak post-meal blood sugar levels up to 44% and lower A1c levels significantly." Sounds like it's a product to treat diabetes?
The product's website scrupulously avoids any reference to the idea of treating "diabetes" -- they only "stabilize blood glucose" - but that doesn't stop on-line discussions with Dr. Zhong from discussing diabetes elsewhere. Of course, if they claimed that the product can treat diabetes, the FDA would pounce. As they say, "The statements made on this website have not been evaluated by the Food & Drug Administration. The FDA only evaluates foods and drugs, not supplements like these products. These products are not intended to diagnose, prevent, treat, or cure any disease. Results may vary."
But one result won't vary: people who buy this concoction will spend a lot of money on the hope that this is something more than snake-oil.
The interested reader might want to read another commentary on this product, Does natural supplement Glucocil live up to the hype?