Are supplements that contain licorice bad for your blood pressure?
Like so many things, it depends. Let’s go over how licorice can raise your blood pressure and then look at what kind of formulas contain this ingredient.
First off, we are not talking, specifically, about black licorice candy. If you are in the US, black licorice candy doesn't generally contain licorice extract but some do, so it is wise to check the ingredients if that is a candy you like.
We are talking about the root of glycyrrhiza glabra, you might see it on labels as licorice (root) or licorice (root honey-fried) or if the ingredients are in Chinese, it is called Gan Cao or Zhi Gan Cao for the honey-fried version. This herb contains a compound called glycyrrhizin. When this compound comes into contact with certain gut bacteria, it is converted into glycyrrhetinic acid.
Now, let’s go to the kidney.
In the kidney there are mineralocorticoid receptors that, when triggered by a steroid hormone, will tell the kidneys to hold onto sodium and dump potassium. This allows for more sodium in the bloodstream which pulls in water from surrounding tissues and increases blood volume which, in turn, increases blood pressure.
The steroid hormone that triggers these receptors is aldosterone but the receptors can’t tell the difference between aldosterone and the stress hormone cortisol - and there is about 1,000 times the amount of cortisol around these receptors than aldosterone. This sounds like a problem, but the receptors have a buddy in an enzyme with the catchy name 11Beta HSD2 and what it does is act like a bouncer by converting cortisol which can activate the receptor into cortisone which cannot.
Remember the glycyrrhetinic acid?
When there is a lot of that around it interferes with that enzyme’s ability to convert cortisol into cortisone and when that happens due to either high doses or long term use then the receptors get tricked by cortisol and the kidneys think that there is a ton of aldosterone around and then we see elevated sodium levels which increase both blood volume and pressure.
What kinds of products have licorice in them that I should know about?
Candy: - as we talked about before, it is a good idea to look at the ingredients of black licorice to see if it contains licorice root extract. If it does contain licorice, be cautious even if you don’t have blood pressure issues.
Energy Supplements: Licorice can up cortisol levels which can make you feel pretty good and some companies will use it for this effect. If you see licorice as one of the first couple of ingredients in a product, it would be good, generally, to avoid it even if your blood pressure is within healthy ranges.
High Dose Herbal Formulas: If you are working with a clinical herbalist with appropriate training, they might want to put you on a formula that has high levels of licorice and this is fine if it is for a short time and they fully understand your health history. Formulas like this can be very helpful to some people but their application needs to be monitored.
Low Dose Herbal Formulas: Most of the time licorice is used, it is used in very small amounts. It is said to “harmonize” the formula. This can happen because the effects of glycyrrhetinic acid are not confined solely to inhibiting the action of 11B HSD2 in the kidney. It has also been shown to have anti-inflammatory and liver protecting effects as well as soothing mucosal linings in the gut which can slow the absorption of metabolism of compounds from other herbs.
How much is too much?
The guidelines for the consumption of glycyrrhizin in otherwise healthy individuals is less than 100mg daily. As an example let’s look at a formula from our lineup.
Decompress is 10% honey-fried licorice root (the highest in our lineup) and given that the amount of glycyrrhizin in the roots varies from plant to plant and harvest to harvest, but in the end averages out to be, let’s say on the high side about 20%.
So, let’s work the math.
We will make it easy and start with 200g of dried herbs to make a 1 Liter batch of Decompress.
10% of that 200g - 20g - is Licorice root.
This 200g of herbs yields about 1,000ml of finished tincture.
Licorice root can contain ~20% glycyrrhizin by weight, on the high end, so 20g of licorice root can contain about 4,000mg of glycyrrhizin. (This estimate is purposefully high 6-8% is common)
Extraction is never 100% efficient, so let’s assume a 70% extraction rate.
That gives us about 2,800mg of glycyrrhizin in the total 1,000ml tincture.
That means each 1ml contains roughly 2.8mg of glycyrrhizin.
A typical dose is 3ml, which would provide about 8–9mg of glycyrrhizin per dose.
Even at three doses a day this is significantly below the 100mg threshold for healthy folks. On average our formulas that contain licorice contain about half this amount.
So what do I do if I have hypertension?
If you have uncontrolled hypertension, it would be best to avoid all products that contain licorice, even ours. I would strongly urge you to take the necessary steps to get your blood pressure under control. Diet and exercise, herbs, drugs - making these changes can significantly reduce your chances of stroke and heart attack.
If you have well controlled hypertension it is unlikely that the amount of glycyrrhizin in our products will have a significant effect on your blood pressure, but it is still a good idea to make sure that your physician knows which supplements you are taking.
If your blood pressure is not an issue for you, then it is unlikely that taking most herbal formulas will have any adverse effect. I would still be cautious about black licorice candy.
