Report on Kelp Side Effects and Usage


Natural health supplements sometimes have unexpected side effects or interactions with medication that can lead to adverse reactions that are sometimes life threatening. The following is a list of cautions that you should be aware of before using kelp (Ascophyllum nodosum, Laminaria digitata). These are referred to as drug/herb interactions.

Warning 1 – Contraindications: Sensitivity to iodine, hyperthyroidism.

Warning 2 – Anticoagulants: Kelp may increase the risk of bleeding when used concurrently with anticoagulants. Experts recommend avoiding concurrent use.

Warning 3 – Antihypertensives: Using kelp increases hypertensive effects. Experts recommend avoiding concurrent use.

Warning 4 – Heavy metals: Kelp is a seaweed which can easily get contaminated from heavy metals like mercury, arsenic, etc. in ocean waters.

Warning 5 – Acne: Some studies have shown that consumption of kelp could lead to acne formation due to its high iodine content. If you already have acne, using kelp may make your condition worse.

Used as a natural health remedy: kelp is used internally for the following benefits and conditions:

  • Alleviate arthritis pain (See other herbs for inflammation)
  • Anti-oxidant
  • Beneficial in endometriosis
  • Diet aid, dissolves fatty wastes
  • Diet aid, to control appetite
  • Diuretic
  • Hair loss
  • Help prevent growth of tumors
  • Help fight against heart disease and cancer
  • Help prevent osteoporosis
  • Help regulate your body temperature
  • Help the development of brain
  • Improve immunity
  • Improve digestion
  • Improve liver function
  • Kills the herpes virus
  • Lower bad cholesterol (LDL)
  • Prevent anemia
  • Prevent muscle cramping
  • Promote fingernail and toenail growth
  • Reduce flatulence
  • Reduce restless leg syndrome
  • Reduce menstrual pain
  • Regulation of thyroid function
  • Relieve constipation

The above benefits have not yet been proven or disproved.

Animal studies at the University of California, Berkeley, found that a diet containing kelp lowered the levels of estradiol in rats. Researchers hope that kelp might be able to decrease the risk of breast cancer in humans.

Side Effects of kelp

The known side effects of using kelp include:

  1. Diarrhea
  2. Nausea

Other side effects may also occur when using kelp. (See form below) In rare cases, kelp can lead to severe allergic reactions.

As with any herb, a serious allergic reaction is possible. Seek immediate medical attention if you notice any symptoms of a serious allergic reaction. These may include a rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.

Return to the Herb List.

For questions and answers about the side effects of herbs see the Herb Forum

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