Also known as: Glycyrrhiza glabra, Deglycyrrhizinated licorice, Glycyrrhizin, Liquorice root
BotanicalEmerging evidence
A traditional soothing herb for the digestive tract, sold in two forms that behave very differently. The deglycyrrhizinated version removes the compound responsible for licorice raising blood pressure.
Typical dose
380.0–1600.0 mg per day
20 minutes before meals; chewable form preferred
What it is
Licorice root comes from Glycyrrhiza glabra, used for thousands of years across Chinese, Ayurvedic and European herbal traditions and as a confectionery flavouring.
Glycyrrhizin is the compound responsible for both the sweetness and the problems. It raises blood pressure and lowers potassium by affecting how the body handles the hormone aldosterone, and the effect is real at ordinary intakes.
Deglycyrrhizinated licorice, DGL, has that compound removed, leaving the soothing flavonoids behind. For any regular use, DGL is the form to buy, and whole licorice extract should be treated with real caution.
How it works
DGL is thought to increase mucus production in the stomach lining, thickening the protective barrier between the lining and stomach acid.
That is a defensive mechanism rather than an acid-reducing one, which is why it is used alongside meals rather than to suppress acid production.
Licorice flavonoids also have anti-inflammatory activity and some effect on the organisms that colonise the stomach lining. Glycyrrhizin has separate effects on cortisol handling, which is why whole licorice appears in some adrenal formulas and why those carry the blood pressure risk.
What the evidence shows
There is older clinical work supporting DGL for digestive comfort and for protecting the stomach lining, some of it comparing favourably with conventional options of the era.
Modern trials are fewer, and much of the enthusiasm rests on that earlier body of research rather than on recent work.
The blood pressure effect of glycyrrhizin, by contrast, is thoroughly documented. That is the best-evidenced thing about licorice, and it is the reason to choose DGL for anything beyond occasional use.
Dosing
DGL is typically used at 380 to 800 mg, taken 20 minutes before meals, up to three times daily.
Chewable tablets are the traditional format, and the reasoning is that saliva contact contributes to the effect. Swallowed capsules may work less well for this purpose.
Check the label says deglycyrrhizinated. Whole licorice extract at any meaningful dose should not be taken continuously, and the safe limit for glycyrrhizin is far lower than most people assume — regular licorice confectionery alone has been enough to raise blood pressure in some cases.
DGL is well tolerated, with the glycyrrhizin removed and few reported effects at typical doses.
Whole licorice is the real concern. Regular intake raises blood pressure and lowers potassium, and this happens at amounts people reach through confectionery and tea without realising.
Avoid whole licorice entirely if your blood pressure is being managed, if you take anything affecting potassium or fluid balance, or during pregnancy. Speak to your doctor before use if you take regular medication.
Who should avoid it
Choose the deglycyrrhizinated form for any regular use. Avoid whole licorice if your blood pressure is being managed, if you take anything affecting potassium or fluid balance, or if you have been told your potassium runs low. Avoid whole licorice in pregnancy. Speak to your doctor before use if you take regular medication.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
