Is licorice safe during pregnancy?

What does the evidence say about licorice during pregnancy?

1. Heavy licorice use during pregnancy, at least 500 mg of glycyrrhizin a week, was linked to about 2.5 times the odds of delivering before 38 weeks, in a Finnish study of over 1,000 mother-infant pairs. 1
2. That same heavy level of licorice use more than doubled the odds of preterm birth overall, and roughly tripled the odds of delivering before 34 weeks, in a follow-up Finnish study. 2
3. Children whose mothers had heavy licorice exposure during pregnancy scored about 7 points lower on IQ tests, had weaker memory, and were over 3 times more likely to show ADHD-type problems by age 12, compared with children of mothers with low exposure. 3
4. Girls, but not boys, with heavy prenatal licorice exposure were taller, heavier, and reached puberty earlier than girls whose mothers had low exposure, in that same study. 3
5. Large amounts of licorice extract, about 250 grams a week, are considered unsafe during pregnancy and can raise the risk of delivering before 38 weeks. 4

Is licorice safe in each trimester?

• First trimester. The research on licorice looked at total intake across pregnancy, not just the first trimester, so there's no evidence that early pregnancy is any safer. This is a good time to swap licorice-root tea for a different herbal tea and keep candy occasional, since early exposure still adds to your total.
• Second trimester. Licorice exposure now adds to the same running total that researchers linked to shorter pregnancies and to differences in children later on, so this trimester isn't a safer time for heavier use. An occasional piece of candy is very different from daily licorice tea or a concentrated extract, and those two are worth avoiding.
• Third trimester. The clearest documented risk is a higher chance of earlier delivery, which makes the third trimester the most important time to have already cut back. If licorice tea or a licorice-containing supplement has been part of your routine, mention it at your next prenatal visit.