Kelp vs. Seaweed: What’s the Difference?

author avatar Dr. Eric Berg 11/08/2023

The term seaweed refers to more than 10,000 species of marine algae and aqueous plants. Kelp is a specific type of brown seaweed much larger than other seaweed species.

Seaweeds are incredibly nutritious plants and sea kelp is a particularly rich source of iodine, an essential nutrient for thyroid health, and contains many health-promoting phytochemicals. 

Let’s take a look at the differences between kelp vs seaweed and learn about kelp’s incredible health benefits.   

sea kelp enhanced iodine

What’s the difference between seaweed and kelp?

While kelp and seaweed are both highly nutritious marine plants that absorb the nutrients from their surrounding waters, they have some differences.

Seaweed is an umbrella term for a wide range of marine-based species of plants and algae, whereas kelp is a specific type of brown seaweed. This means that all kelp is seaweed, but not all seaweed is kelp.

The main differences between kelp and seaweed are their size and nutritional value.  

Kelp is much larger and contains more iodine compared to other seaweeds. However, other types of seaweeds may have higher levels of other essential nutrients depending on their particular characteristics and growth location. 

Dried seaweed

What is seaweed?

Seaweed refers to any aqueous plant or algae that grows in a saltwater marine environment. It grows in various shapes, sizes, and colors and can be found on rocky coastlines in the intertidal zone or deep ocean waters.

Its color has a direct effect on how much light seaweed absorbs and determines how close to the ocean's surface a specific species grows. 

There are three broad seaweed categorizations based on their pigmentation:

  • Green algae

  • Brown algae 

  • Red algae 

Most seaweeds contain high amounts of vitamins and minerals and are popular sea vegetables consumed by many cultures worldwide. 

What is sea kelp?

Kelp is a specific type of large brown seaweed that typically grows in cool and nutrient-rich waters. 

It’s characterized by long, leaf-like blades and has flexible but sturdy stems. Giant kelp, a large seaweed species found predominantly in the Pacific Ocean, can grow up to 60 meters in length. 

Kelp forests are an important habitat for marine life, and many coastal communities consume kelp as a staple ingredient in salads, soups, stews, and sushi rolls. 


Health benefits of kelp and seaweed

Kelp and seaweed have been used for centuries as a source of nutrition and a natural remedy to lower inflammation, boost immunity, and support digestion.

Here are seven health benefits of kelp!

1. Nutritional powerhouse

Kelp ranks amongst the most nutritious seaweeds. It’s loaded with vitamins, minerals, and fatty acids. 

“Compared to the terrestrial plants and animal-based foods, seaweed is rich in some health-promoting molecules and materials such as dietary fiber, omega-3 fatty acids, essential amino acids, and vitamins A, B, C, and E.” says Niranjan Rajapakse, biochemist and lead author of research published in Advances in Food and Nutrition Research investigating the health benefits of sea kelp.

2. Supports thyroid health

Kelp is an exceptionally concentrated source of iodine, an essential mineral for normal thyroid function.


Without adequate iodine, the thyroid gland can’t produce and convert thyroid hormones, resulting in underactive thyroid function, also called hypothyroidism.

This study published in Hormone Research in Paediatrics suggests that taking iodine-rich seaweed supplements improves thyroid function in people with hypothyroidism and goiter.

3. May help to lower inflammation 

Seaweed species, including kelp, contain specific antioxidants such as laminarin and fucoxanthin that have potent anti-inflammatory properties.

Research published in Marine Drugs suggests that these seaweed-derived phytochemicals block the production of pro-inflammatory compounds and, at the same time, stimulate the release of anti-inflammatory molecules.

Kelp’s impressive anti-inflammatory effects may explain why kelp can benefit a wide range of chronic inflammatory conditions, including rheumatoid arthritis, psoriasis, and asthma.

4. Promotes healthy weight 

Using kelp may help with weight loss. Iodine has been found to have potential fat-burning effects by promoting metabolic health. 

Iodine deficiency can decrease your basal metabolic rate, which promotes fat storage and leads to weight gain and difficulty losing weight. 

5. Supports reproductive health 

Iodine in kelp supports thyroid health which is crucial for healthy hormone balance and reproductive health.

In addition, kelp contains several antioxidants that protect both egg and sperm cells from inflammation and cellular damage, which supports fertility and reproduction.   

6. May lower cancer risk

There is evidence that regular seaweed consumption may lower the risk of cancer.

Although more research is needed to confirm kelp’s anti-cancer effects, several bioactive kelp compounds, including polysaccharides, fucoidans, and phlorotannins, protect cell structures and DNA from oxidative damage, which may lower the risk of cancer. 

7. Natural diuretic 

Kelp has mild diuretic effects and stimulates urine production, which helps flush excess fluids and toxins from the body. 

Increased urine output also promotes healthy blood pressure and prevents water retention and bloating.

sea kelp enhanced iodine

Who should use kelp

Kelp is a rich source of nutrients and dietary fiber, and most people benefit from regularly consuming kelp. 

Because kelp boats incredible amounts of iodine, it's particularly beneficial for people with thyroid disorders and those at risk of low iodine intake and malabsorption. 

A recent study published in Nutrients found that vegans and vegetarians are at increased risk of iodine deficiency.

In addition, industrialized farming has depleted iodine in a significant percentage of soils, and obtaining adequate amounts of this essential mineral from dietary sources alone is becoming increasingly more challenging.

Due to its wide range of health benefits, kelp use has been found beneficial for these conditions:

Fresh kelp

Who shouldn’t use kelp

Kelp is generally safe and well-tolerated by most people. 

However, due to its high iodine content, kelp can interfere with thyroid function, and people with hyperthyroidism and autoimmune thyroiditis shouldn’t use kelp products.

Kelp is rich in vitamin K, which impacts blood clotting. If you are taking blood thinning medication such as warfarin, it’s essential that you discuss the use of kelp with your healthcare provider to avoid excessive bleeding or other blood conditions.

How do you know if you’re low in iodine?

Iodine is essential for thyroid function, which regulates your metabolism, muscle function, hormone balance, digestion, and cognitive health. 

Unsurprisingly, iodine deficiency can impact your whole body and manifest in a wide range of symptoms. 


Here are common signs and symptoms of iodine deficiency:

  • Swelling in neck 

  • Unexplained weight gain

  • Intolerance to cold

  • Dry skin and brittle nails 

  • Fatigue

  • Muscle weakness

  • Sluggish digestion 

  • Constipation

  • Brain fog 

While these symptoms may indicate low iodine levels, they can also be caused by other health problems, and it’s important to consult with a healthcare provider if you experience any of these symptoms to address potential medical issues and formulate an appropriate treatment plan. 

sea kelp enhanced iodine

Could sea kelp benefit you?

The human body can’t produce iodine and relies on dietary sources to obtain this essential nutrient. Unfortunately, mineral-depleted soils can make it hard to get all the iodine your body needs.

And, what’s more, environmental pollutants and toxins, including fluoride, chlorine, bromine, and even soy, can inhibit the absorption of iodine, leaving you at risk of deficiency.

Kelp and seaweed products have become increasingly popular in recent years—and for a good reason!

Sea kelp is one of the world’s most concentrated sources of iodine, and taking a high-quality kelp supplement is an effective way to promote healthy iodine levels and support metabolic health,” says Dr. Berg.

Using sea kelp may help you to:

  • Support normal thyroid function  

  • Feel rejuvenated and energized 

  • Improve focus and mental clarity 

  • Lose weight 

  • Support digestive function 

  • Enhance reproductive health 

  • Combat inflammation 

  • Lower the risk of cancer 

  • Support healthy skin and nails

However, it’s important to understand that not all sea kelp supplements are the same. Like all seaweeds, kelp doesn’t just absorb nutrients from its surrounding waters. It also accumulates toxins! 

Unfortunately, many low-quality kelp products are made from kelp grown in polluted waters.

Using these supplements can expose you to harmful heavy metals, which can cause gastrointestinal issues, inflammation, hormone imbalances, and immune reactions.  

That’s why we searched wide and far to identify the highest-quality marine iodine sources available.

All ingredients in Dr. Berg Sea Kelp Enhanced Iodine are sourced from world-leading suppliers and harvested from pristine underwater forests.

Woman holding sea kelp capsule

A premium seaweed complex made with your health in mind 

If you feel you could benefit from a clean and highly concentrated source of iodine and other health-promoting nutrients, check out Dr. Berg Sea Kelp Enhanced Iodine. 

We have decades of experience working with patients and developing high-quality products that deliver incredible results.

Sea Kelp Enhanced Iodine contains Laminaria digitata, a particularly iodine-rich kelp species, and includes red marine algae and Klamath blue-green algae with potent antioxidant and anti-inflammatory properties for maximum benefit. 

A single capsule of Dr. Berg Sea Kelp Enhanced Iodine delivers 200 mcg of iodine, that’s more than 100% of the daily recommended daily intake for most people.

Our ingredients are sourced from only the top domestic and international suppliers—and all Dr. Berg products are made with USA GMP-certified manufacturing facilities.

Compared to many other seaweed supplements, our formulation doesn’t contain hijiki seaweed. This abundant and cheap seaweed species tends to accumulate excessive levels of arsenic and can cause neurological problems. 

Sea Kelp Enhanced Iodine is an excellent choice for those looking for a pure source of iodine, and it’s safe to have on a Healthy Keto® and intermittent fasting plan.

Most importantly, we stand behind our products. If you don’t love the results, you can take advantage of our 30-day money-back guarantee, no questions asked!

Our decades of experience, unique formulas, and high manufacturing standards ensure you get only the best quality products—every time.

Click on the product below to learn more about Dr. Berg Sea Kelp Enhanced Iodine!

sea kelp enhanced iodine


1. Which is more nutritious: seaweed or kelp?

While seaweed and kelp are both incredibly nutritious marine plants rich in essential nutrients, kelp contains more calcium and has a significantly higher iodine content than most other seaweeds. 

2. Is kelp a seaweed or algae?

Kelp is a type of large brown seaweed.


3. Does kelp taste like seaweed?

Kelp is a type of seaweed with a similar taste to other kinds. The flavor profile somewhat depends on the kelp species and growth location. However, most kelp has a mild, slightly sweet, and salty flavor. 

4. Why is seaweed called kelp?

Kelp is classified as seaweed. While not all seaweed is kelp, kelp is always a type of seaweed. 

5. Are kelp and seaweed the same?

No, kelp and seaweed aren’t exactly the same. 

Seaweed refers to a large group of sea plants and marine algae. Kelp, on the other hand, is a specific type of large brown seaweed that can grow up to 60 meters (196 feet) high.

6. What are the health benefits of kelp?

Kelp is incredibly nutritious and rich in vitamins, minerals, antioxidants, and anti-inflammatory phytochemicals. 

Kelp supports healthy thyroid function, promotes gut health and strong immune defenses, and has been found to help weight loss, lowers inflammation, and may reduce your risk of developing certain types of cancer. 


7. Who shouldn’t use kelp?

Individuals with hyperthyroidism and autoimmune thyroiditis should avoid kelp due to its high amounts of iodine. 

In addition, kelp can interfere with blood coagulation, and it’s essential that you discuss the use of kelp with your healthcare provider if you are taking blood-thinning medications or have a blood clotting disorder. 


8. Is arsenic in sea kelp dangerous?

Arsenic in high doses can be harmful, and the amount of arsenic in kelp depends on its growth location. To reduce the risk of arsenic exposure from sea kelp, it’s essential to choose a high-quality kelp product grown and harvested in carefully monitored, pollutant-free marine environments.  

9. How do I take Dr. Berg Sea Kelp Enhanced Iodine?

You can take 1 capsule of Dr. Berg Sea Kelp Enhanced Iodine in the morning with or without food.

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