Q. I read in a women’s magazine that natural licorice candy can help in lowering blood glucose levels. I am 37 and considered pre-diabetic. I am not overweight.
Have you heard of this use of licorice? How much licorice is safe to consume? Can it interfere with any medications?

A. We were surprised to discover that licorice extract can indeed help control blood sugar in diabetic rats (Journal of Pharmacy and Pharmacology, Feb. 2011). Licorice candy, with its added sugar, would presumably be counterproductive.
Long-term use of licorice can lead to fluid retention, increased blood pressure, loss of potassium and lowered libido. It can interact with numerous drugs, especially heart medicine like digoxin or diuretics like furosemide.
We would discourage your use of licorice for treating pre-diabetes since we don’t have dosing information for humans.

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  1. Rob
    Reply

    I just had my medication increased to 2 pills twice daily. I found the 2 pills to be very hard on my stomach. I started eating a few pieces of black licorice with the meals that I take 2 pills, and find it helps settle my stomach. I also noticed that my sugar levels have been the lowest they have been in months. I just got an 8.1 tonight. I have been mid to high teens for the past month. So it’s possible that black licorice helps.

  2. Carol
    Reply

    I prepared one Licorice tea bag and noticed I was light headed and unstable when I stood up and walked. I think it brought my glucose level too low. Is that possible? It was about six hours since I ate.

  3. bp
    Reply

    I was using a natural health drink touted to boost vitality and deliver nutrients and minerals. In about 3 weeks of 1oz daily added to juice I found my blood pressure went up from a lifetime of steady 110/70 to 130/85. The only change in lifestyle was the drink. I saw my physician, we googled many of the ingredients, but the licorice root was determined to be the culprit, and it took almost 3 months for my pressure to return to normal. I avoid it!

  4. BK
    Reply

    DH:
    No I did not receive any input regarding the quantity of licorice that can be consumed before one experiences any side affects listed. Comments from anyone? Joe, Terry?
    PEOPLE’S PHARMACY RESPONSE: ACCORDING TO THE NATURAL MEDICINES COMPREHENSIVE DATABASE, CONSUMING ABOUT AN OUNCE A DAY FOR SEVERAL WEEKS CAN LEAD TO THE SIDE EFFECTS WE DESCRIBED. PEOPLE WHO ALREADY HAVE RISK FACTORS SUCH AS HIGH BLOOD PRESSURE OR KIDNEY PROBLEMS CAN GET INTO TROUBLE WITH JUST 5 GRAMS A DAY (NOT MUCH) FOR A FEW WEEKS. PREGNANT WOMEN SHOULD PRETTY MUCH AVOID TRUE LICORICE.

  5. DH
    Reply

    BK,
    Did you ever get an answer to your question? That would be my question also exactly how much is considered long term or would daily consumption be harmful? If you eat it a few weeks and then none for a month or so is that ok? Would you email me and let me know if you got an answer.
    Thank you
    dh

  6. James
    Reply

    I don’t know about licorice, but my own research has left little doubt that the single most effective thing to improve insulin sensitivity (and glucose results) is regular moderate to vigorous aerobic exercise (at least 3 times per week). This should make a fairly dramatic difference, fairly rapidly. As for foods and/or supplements, studies seem to indicate that alpha-lipoic acid is safe, and should improve insulin sensitivity & glucose results. (So does chromium, but I wouldn’t be comfortable with the safety profile of chromium). If you don’t get enough magnesium in your diet, a magnesium supplement may also improve your glucose numbers.

  7. RH
    Reply

    The person that asked about licorice and blood sugar should try Cinnamon. I put it on my oatmeal every morning and it keeps my A1C in a good place. I have been a diabetic for almost 35 years. I am now 8l years old.

  8. James J Vogel, PhD
    Reply

    Actually there is new clinical evidence from Japan that licorice contains a polyphenol that lowers blood sugar and reduces visceral fat. The compound is called glabridin that can be extracted from licorice root with alcohol. Glycyrrhizin, the molecule that causes an increase in blood pressure is only water soluble so is not extracted. The trade marked product Glavonoid is available in Health Food Stores. Swanson Health Products has Licorice Flavonoid Oil in their latest catalog.

  9. BK
    Reply

    We often hear the term “……….long term use.” What does that mean? I have a small piece of licorice every day or so. Will that cause any of the issues stated in the article?
    PEOPLE’S PHARMACY RESPONSE: “A SMALL PIECE” IS NOT VERY SPECIFIC, AND THERE IS PROBABLY A RANGE OF SUSCEPTIBILITY, SO WE DON’T KNOW FOR SURE.

  10. a.s.
    Reply

    DGL- has the bad stuff removed; has no sugar. i can’t spell the full name right now; google it.

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