Most people think of licorice (liquorice in Europe) as yummy candy. We happen to be licorice lovers ourselves. Natural black licorice from the Netherlands is one of our favorite sweet treats. But we are very careful not to over indulge. That’s because natural licorice side effects can be serious. They include hypertension and hormonal imbalance. Such adverse reactions to licorice can sneak up on people, as this reader discovered:

Licorice and Swollen Feet (Edema):

Q. I just got back from a trip to Ireland. They have delicious licorice over there in every candy store. I had a bag every day and loved it.

On the plane flight home, my legs swelled terribly. My feet were practically bursting out of my shoes.

I think the licorice, together with the hours of sitting still, made this happen. Now that I’m back home and can’t get licorice every day, my legs are normal again.

A. An ingredient in natural black licorice, glycyrrhizin (Glycyrrhiza glabra) has powerful pharmacological activity. It has been used as a medicinal herb for thousands of years. Healers have used it to treat digestive upset, ulcers, colds, sore throats, congestion, coughs, and asthma. It has intriguing hormonal activity. Some women have used it to ease hot flashes (Electronic Physician, Nov. 25, 2017).

Too Much Licorice is Dangerous!

Overdosing on natural licorice can cause low potassium levels, abnormal heart rhythms, headaches, edema (swelling) and high blood pressure.

Some people may be especially susceptible to licorice side effects.

Here is a message from Kristina in California:

“I was placing a vitamin order recently and on a whim, threw in a small box of good European black licorice. I ate it over two days. On the third day noticed that my ankles and feet were hugely swelled. At first I had no idea what was going on, but was very worried.

“Congestive heart failure, I thought? Then it occurred to me that the licorice was the culprit. I immediately started to drink coconut water and ate a banana and also took powdered potassium, a very small amount at a time.

“It took a few days, but the swelling left. I will never eat black licorice again. I feel like if I had eaten even more, it could have been a fatal overdose of candy. Imagine that. How would you like that listed on an autopsy report as the cause of death?”

If you find that hard to believe, here is a fascinating account of scary licorice side effects published in The Lancet (Feb. 19, 1979).

Unusual Licorice Side Effects Include Low Libido:

This case comes from the Department of Endocrinology at the Karolinska Hospital in Stockholm, Sweden:

“A 22-year-old gymnastics teacher without any previous serious illness or medications was investigated in 1973 because of secondary amenorrhea [loss of periods] and impaired libido…

“In 1977, she attended [the] hospital because of attacks of severe headache for 11/2 years. During attacks, which occurred about once a month, the pain began in the forehead and then spread, ending in vomiting and photophobia [sensitivity to light]. Blood pressure during attacks and during observation on the ward was 240-210/130-100…with a pulse rate of 44-60/min.

“On careful questioning the patient said she had for several years been eating excessive amounts of liquorice. When the liquorice was withdrawn, the blood pressure returned to normal within 2 weeks…after 6 months, when the hormone levels had gradually returned to normal, menstruation returned. She has had no headache attacks…The symptoms of this patient–headache, vomiting, and photophobia–indicate liquorice toxicity…”

Although the authors did not mention it, we assume her libido also returned to normal after her hormonal balance was reestablished. She experienced high levels of prolactin because of the natural licorice she was eating. That hormonal effect might have been responsible for her low libido.

The elevated blood pressure 240/130 could have caused a stroke. Fortunately, her endocrinologists figured out the reason behind her symptoms and the story had a happy ending.

Licorice and Low Potassium Levels

It’s not just natural licorice candy that poses a risk. Last summer we heard from a daughter concerned about her mom:

“My mother was just released from the hospital. She went in when her potassium dropped to 1.2. She could have died, and doctors were surprised that she didn’t.

“I looked online and found a case study of a man who ate a lot of licorice cough drops; his potassium dropped to 1. I asked my mother and found out she has been taking a licorice root supplement for quite some time.

“The doctors never asked her about anything she was taking. They just pumped her full of potassium. Three days in a hospital might have been avoided.”

One Way to Reduce Licorice Side Effects:

Carol in Colorado points out that there are DGL licorice root products that are safer than standard licorice:

“PLAIN licorice root contains STEROID-LIKE factors in it, naturally, that (like steroid drugs/medications) can cause a dangerous loss of potassium. It can also cause edema (holding onto fluid, causing swelling), etc.

“Luckily, some genius, some years ago, figured out how to REMOVE these steroid-like factors from plain licorice root, leaving DGL (De-Glycyrrhizinated Licorice) behind. (De = without, and Glycyrrhizins = steroid-like components/ingredients normally found in plain licorice root).

“DGL has many healing properties. From label instructions, it says that the DGL should be briefly chewed (a few seconds) to get the DGL to be mixed with saliva. This apparently activates the DGL to do its job of helping to prevent gastric reflux, and to help heal injured stomach linings, by promoting the re-growth of destroyed mucus-producing cells in the lining of the stomach.”

If you can pronounce deglycyrrhizinated without stumbling, you get The People’s Pharmacy gold star award! That is a tongue twister. It would also stump almost any wannabe spelling bee star. That said, there are those who think deglycyrrhizinated licorice (DGL) is helpful for digestive upset. There is even research suggestion that a DGL mouth wash can help heal canker sores (aphthous ulcers) (Journal of the Association of Physicians of India, Oct. 1989).

Susan in North Carolina adds her support for DGL:

“I think it would be helpful to mention that deglycyrrhizinated licorice in capsule form is widely available, provides the same benefits, and does not present the dangers of the ‘natural’ form.”

The People’s Pharmacy Perspective:

When it comes to natural black licorice candy a little goes a long way. Daily “dosing” is not a good idea. We think this sweet treat should be savored occasionally. We do not want anyone to experience life-threatening licorice side effects! Low potassium levels can sneak up on you with few, if any, warnings. And remember, when potassium levels get too low, irregular heart rhythms can follow, including the ultimate: cardiac arrest!

As for DGL, we do think it has a possible role in dealing with indigestion. In our Guide to Digestive Disorders we have tips from Dr. Tieraona Low Dog. This medical doctor appreciates the science behind natural approaches. She has tips for getting off PPIs (proton pump inhibitors) for heartburn symptoms that include DGL. Here is a link:

Guide to Digestive Disorders

Do be careful with DGL, though. Some people are so sensitive to glycyrrhizin that even the tiny amounts left in deglycyrrhizinated licorice can pose a problem One person discovered that his blood pressure started going up after about a month on DGL.

Share your own licorice (or DGL) story below in the comment section.

Related People's Pharmacy Health Guide

Watch a brief welcome from Joe & Terry

Your browser doesn't support HTML5 video.