May I Take Herbal Medicine While Pregnant or Breastfeeding?

"I'm pregnant—can I take herbal medicine?"

The answer to this question changes completely depending on to whom, when, and what is used.

Still, the principle is clear. In the body during this period there are two people. So I look far more narrowly and far more cautiously than usual.

Why This Period Is Different

During pregnancy, the body's conditions change wholesale. Blood volume increases, the work the liver and kidneys must process increases, and the hormonal landscape shifts. The same medicine moves differently from usual.

And crucially, some of a medicine's components pass through the placenta. If you are breastfeeding, some also cross over into breast milk. A child is smaller than an adult and less mature in its ability to process. An amount that poses no problem for an adult may be different for a child.

This is not a story unique to herbal medicine. It is a principle that applies to all drugs. It is the same reason obstetrics is selective about which drugs to use.

So I Divide It This Way

First, there are materials I do not use. There are materials with a tendency to stimulate the uterus, to move the blood strongly, or to strongly induce discharge. I do not use such materials during pregnancy.

In early pregnancy, the period when the baby's nervous system and organs are being formed, the worry of the mother and her family is especially great. I know that worry. So my judgment in this period is made to fit the situation, and made that much more carefully.

Second, there are materials I use with caution. Even materials known as common and gentle are no exception. Materials that affect electrolytes and blood pressure, like licorice, can become entangled with swelling and blood pressure during pregnancy. (Herbal Medicine Has Side Effects Too — The Story of Licorice)

Third, there are nonetheless cases where it is needed. Cases of severe morning sickness where one can neither eat nor drink; cases where postpartum recovery is slow and the body keeps breaking down. There are clearly situations where doing nothing is more dangerous. In these cases I use it only as much as needed, briefly, while monitoring.

The Postpartum Period Is Different Again

After childbirth, the situation changes. The body is greatly depleted, sleep is interrupted, and there is much to recover. Many people seek herbal medicine in this period.

Here too, I do not think first of "tonifying." Because recovery does not happen through filling alone. Whether digestion works, whether one can sleep, whether swelling is going down—I look first at the conditions that let the body turn recovery on. (Tissue You Don't Use Withers — But Filling It In Doesn't Bring It Back to Life)

And if you are breastfeeding, you must tell me in advance. During nursing there are materials that must not be used or whose amounts must be changed. If the baby fusses more than usual, becomes limp, or has diarrhea, stop the medicine and let me know.

The Things I Always Ask

For someone who is pregnant or breastfeeding, I check the following first:

• How many weeks along you are, or how long it has been since delivery
• Whether you have a diagnosis or precautions received from obstetrics (gestational hypertension, gestational diabetes, preterm labor, etc.)
• What you are taking these days — including what obstetrics has recommended you take
• Whether you have a history of miscarriage or preterm birth
• Whether you are breastfeeding, and how many months old the baby is

Without this information, I do not prescribe during pregnancy. If I do not know, it is right not to do it.

What I Ask of You in This Period

In this period above all, whatever you take, please ask before you take it.

"They say it's good for pregnancy," "they say eating this after birth takes the swelling down" — before you start something on hearing this kind of thing, just check with me once. If it is something I can look at, I will look at it; if it is something I cannot judge, I will tell you so. (Where Did That Herbal Material Come From?)

Cases Where You Should Go to a Hospital First

If there is bleeding, if your abdomen hurts at regular intervals, if fetal movement has noticeably decreased compared with usual, if there is a sensation of water flowing, or if you have a fever — an obstetrics consultation comes first, before discussing herbal medicine. The same goes for a headache that comes with blurred vision; it can be a sign of gestational hypertension. Swelling in itself is a common thing during pregnancy. And the same applies when postpartum bleeding increases again, or when breast engorgement is accompanied by a high fever.

"Never" and "it is fine" are both wrong

Both "no herbal medicine during pregnancy" and "herbal medicine is natural, so it is fine" are wrong.

The correct statement is this: In this period there are clearly materials that cannot be used, materials that must be used with caution, and cases where they can be used when needed. Someone who knows that distinction using it while monitoring—that is my job.

Do not hesitate; tell me your current state exactly as it is. We will judge it together.

---

References

• A review of how drugs cross the placenta — the basis for what must be examined during pregnancy — Frontiers in Pharmacology, 2023
• The official US National Institutes of Health resource on the extent to which drugs and herbal materials pass into breast milk (LactMed) — NIH National Library of Medicine

Written by Dr. Heo Ji-young (PhD in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)