Kelp Laminaria (Macrocystis pyrifera)

Laminaria is a type of seaweed that is native to Japan. Laminaria contains iodine, an element that the body needs to make thyroid hormones. It is also a rich source of iron and potassium. Despite serious safety concerns about laminaria, some people use laminaria as medicine.

Laminaria is used for weight loss, high blood pressure, as a bulk laxative for constipation, and for treating radiation sickness. It is also used for preventing cancer.

Sometimes healthcare providers use laminaria to expand the cervix, the mouth of the uterus, before certain medical procedures. They place a layer of laminaria directly inside the cervix, the “neck” of the uterus. This layer of laminaria is sometimes called a “tent.” The purpose of the tent is to enlarge the cervix before “D&C,” also known as dilation and curettage (scraping of the uterus); removal of a medical device that is in the uterus; diagnostic procedures; placement of radium for cancer treatment; and other gynecological procedures. Laminaria tents are also used in pregnant women to “ripen” (expand) the cervix to make labor and delivery easier, and also to cause abortions during the first three months of pregnancy.

How does it work?

Laminaria seems to be able to form a thick, sticky gel when it comes into contact with water. This allows laminaria to work as a bulk laxative. It also allows laminaria “tents” that have been placed inside the cervix to expand the cervix for procedures or to “ripen” the cervix and speed up the onset of labor. These laminaria tents absorb water, gradually swelling to a diameter of 1/2 inch over 4-6 hours. This swelling causes the cervix to expand, and that can bring on labor.

Weight loss.
Thyroid.
High blood pressure.
Cancer prevention.
Heartburn.

The appropriate dose of laminaria depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for laminaria. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Kelp is SAFE when taken in the right amount. The average kelp-based supplement might contain as much as 1000 mcg of iodine. Taking in more than 150 mcg of iodine per day can cause a normal thyroid to become overactive or underactive, or make an overactive thyroid worse.

Pregnancy and breast-feeding: The use of kelp directly on the cervix during pregnancy or childbirth is UNSAFE. It can cause serious side effects for both mother and child, including infection, rupture of the cervix, and infant death. Taking kelp by mouth during pregnancy is also UNSAFE because kelp can affect hormones.

Taking kelp by mouth during breast-feeding is LIKELY UNSAFE. If you are pregnant or breast-feeding, it's best to avoid kelp.

Kidney problems: Kelp might cause dangerously high potassium and iodine levels. Don't take kelp if you have kidney problems.

Thyroid problems: Kelp contains significant amounts of iodine, which might make thyroid problems worse.