Health Guide


What is it?

Laminaria is an herbal medicine used to induce labor and abortion. The dried stem of Laminaria mechanically dilates the cervical opening by absorbing water and swelling to several times its original diameter. Laminaria is a marine algae which provides a good source of protein, vitamins, minerals, and carbohydrates. It only contains small amounts of fat.

Other names for Laminaria include: Laminaria Japonica, Laminaria Angustata, Laminaria Digitata, Laminaria Religiosa, Laminaria Saccharina, Brown Seaweed, Seaweed, Marine Algae, and Kelp.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breastfeeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much Laminaria you should take. The amount depends on the strength of the medicine and the reason you are taking Laminaria. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.


  • Before taking Laminaria, tell your doctor if you are pregnant or breastfeeding
  • If you have kidney problems or dehydration, you should not take Potassium without first consulting your health care professional (1)

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Pain (5), mild cramping (2), fever (4) have been reported during induction of labor or abortion with Laminaria
  • Other complications during the use of Laminaria for dilation of the cervix include cervical lacerations (tears to the cervix) (5), endometriosis (swelling and pain of the lining of the uterus) (6), and Laminaria fragments remaining in the cervix (7)


1. Tohan N, Tejani N, Varanasi M et al: Ripening of the term cervix with laminaria. Obstet & Gynecol 1979; 54(5):588-590.

2. Lackritz R, Gibson M & Frigoletto F: Preinduction use of laminaria for the unripe cervix. Am J Obstet & Gynecol 1979; 134(3):349-350.

3. Jurkovic N, Kolb N & Colic I: Nutritive value of marine algae Laminaria japonica and Undaria pinnatifida. Die Nahrung 1995; 1:63-66.

4. Atlas RO, Lemus J, Reed J et al: Second trimester abortion using prostaglandin E2 suppositories with or without intracervical Laminaria japonica: a randomized study. Obstet Gynecol 1998; 92(3):398-402.

5. Strauss J, Wilson M, Caldwell D et al: Laminaria use in midtrimester abortions induced by intra-amniotic prostaglandin F2alpha with urea and intravenous oxytocin. Am J Obstet Gynecol 1979; 134:260-264.

6. Gower R, Toraya & Miller J: Laminaria for preinduction cervical ripening. Obstet & Gynecol 1982, 60(5):617-619.

7. Borgatta L & Barad D: Prolonged retention of laminaria fragments: An unusual complication of laminaria usage. Obstet & Gynecol 1991; 78(5):988-990.


Last Updated: 7/4/2018
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