Chlorella, a so-called superfood, is a fast growing alga that may have a range of health benefits. Some people use it as a nutritional supplement. Chlorella nutrition can depend on the way a person grows and prepares it.

Chlorella is a single-celled, freshwater alga, native to Taiwan and Japan. It is naturally rich in proteins, vitamins, minerals, and dietary fiber. Its reported benefits include boosting antibody count, promoting weight loss, and fighting cancer and other diseases.

Chlorella contains a range of nutrients, including proteins, omega-3 fatty acids, vitamins, and minerals, including antioxidants.

Chlorella has a tough, rigid cell wall that makes it hard to digest in its natural form. Processing makes its nutrients digestible.

Some people have proposed using chlorella as a source of protein and other nutrients to feed a growing global population. Others have suggested it as an alternative and renewable fuel source for agricultural equipment.

In the United States, however, people mostly use it in tablet, powder, or a liquid form as a nutritional supplement. Various types of chlorella are suitable for use as food supplements.

Read on to find out what the research says about the benefits of chlorella.

Chlorella shows promise as a source of protein, but it may have other health benefits.

Boosting the immune system

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Chlorella may help boost the immune system.

A 2012 study looked at how chlorella affects the immune system of humans.

Thirty Korean people who took 5g of chlorella (tablets) for 8 weeks underwent various biological changes that suggested chlorella might strengthen the immune system.

Some medical conditions and treatments can lead to a weakened immune system. How can you stay healthy when this happens? Learn more here.

Protection against dementia

A 2009 mouse study found that chlorella played a significant role in preventing age-related mental decline. This could be due to chlorella’s antioxidant effects on the brain.

However, it is not clear whether chlorella will have the same effect on people.

Lapses in memory can be an early sign of dementia. Get some tips on how to improve your memory.

During pregnancy

Chlorella contains iron, folate, and vitamin B-12. Some researchers have suggested that it might reduce high blood pressure during pregnancy.

Thirty-two Japanese women who took 6g of daily chlorella supplements from weeks 12–18 of pregnancy had lower levels of anemia and fewer signs of pregnancy-induced hypertension than those who took a placebo.

People should always speak to a doctor before taking any supplements during pregnancy. Some products can pose a risk to the pregnant woman and the unborn child.

Some supplements have been proven safe to use during pregnancy. Click here to find out which ones.

Endurance capacity

In a 2014 study, researchers looked at how taking 15 chlorella tablets twice a day for 4 weeks affected the peak oxygen intake in humans. Ten young people took either chlorella or a placebo.

Those who took chlorella saw an increase in their peak oxygen intake, indicating that chlorella might help increase aerobic endurance capacity.

This was a small investigation, and it had various limitations. However, it could mean that chlorella might one day play a role as a supplement for athletes.

Fighting BPA

Estrogen is a hormone that occurs naturally in the body.

However, some substances that mimic the activity of estrogen can cause damage to the body. These substances, known as xenoestrogens, can enter the body through contaminated soil, water, air, plastics, and other sources. Xenestrogens may increase a person’s chance of developing various types of cancer.

In a 2009 study, Chlorella fusca removed 90% of an xenoestrogen known as bisphenol A (BPA) from a laboratory culture.

How can BPA affect a person’s health? Find out here.

The exact balance of nutrients in chlorella will depend on the type and the way people grow and process it.

Below are some of the nutritional benefits of chlorella.

Which supplements do experts recommend for vegans? Find out here.


Chlorella can contain up to 70% dry weight protein.

One mouse study has shown that the body absorbs protein from three types of chlorella effectively. This is rare for plant protein sources. It makes chlorella a suitable protein option for vegans.

Click here for more information on protein-rich vegan foods.

Vitamin B-12

Chlorella is one of the few plant sources of vitamin B-12.

Research published in 2015 found that B-12 from Chlorella pyrenoidosa helped improve the health markers of 17 vegans and vegetarians aged 26–57 years who had a history of B-12 deficiency. A dosage of 9 g per day appeared to be effective.

Findings showed that the body could absorb B-12 from chlorella effectively. This could make chlorella a useful option for some people with a vitamin B-12 deficiency, including vegans and vegetarians.

Who needs vitamin B-12 supplementation? Find out here.


Chlorella is rich in iron and can help prevent iron deficiency anemia.

In a 2009 study, women who took a 6g chlorella supplement during pregnancy experienced significantly lower rates of anemia than women who took a placebo.

Learn more about why the body needs iron and where to get it.

Chlorella is available as a supplement in liquid, powder, or tablet form.

People can add chlorella powder to salad dressings, beverages, and baked goods to boost their nutritional value.

In 2018, researchers found that an algae based diet that included chlorella had no adverse effects on mice.

The mice tolerated the diet well and did not show any signs of damage to their liver, heart, or kidney functions. They also absorbed similar levels of protein to mice who consumed a soy based diet.

Sensitivities and allergies

In 2011, the American Cancer Society cautioned that there was not enough evidence to suggest that chlorella can fight cancer or any other human disease.

They also warned people to stop taking chlorella if they noticed signs of sensitivity or allergic reaction.

Viruses and contamination

Viruses can sometimes affect green algae, such as chlorella.

There is some evidence that algal viruses could affect humans. A 2014 mouse study suggested that one algal virus could affect memory and other cognitive functions.


Research dating back to 1996 found endotoxin-like properties in an extract of chlorella.

Under laboratory conditions, scientists have found evidence that endotoxins can cause inflammation in humans. The effect depends mainly on the size of the dose, however.

Check first with a doctor

A supplement is not a medicine. Often, it can provide a small amount of a nutrient but not enough to have a significant impact on a person’s health. For this reason, people should use supplements alongside any other treatment plan and not as a substitute.

The Food and Drug Administration (FDA) do not regulate the safety and effectiveness of supplements in the U.S. However, recently, many chlorella products have gained GRAS designation, which means they are “generally recognized as safe.”

While the supplement may be safe, however, it may not contain enough active ingredients to make it effective. It could, therefore, be a waste of money.

Anyone who is considering using chlorella as a supplement should speak to a doctor first. They should also ensure they are buying the right type and that they purchase it from a reputable source.

Supporters of chlorella say it is a highly nutritious dietary supplement that can make up for some of the nutrient deficiencies that vegetarians and vegans commonly experience.

Some early scientific evidence supports its use in boosting health and wellbeing, but more research is necessary to confirm these claims.

As a dietary supplement, chlorella may have some benefits. However, people should always check with a doctor first to ensure a supplement is safe for them to use.


Can supplements like chlorella really help, or is it better to get our nutrients from a diet with plenty of fresh fruits and vegetables?


Current evidence suggests that chlorella could be a beneficial supplement to complement a diet rich in fruits and vegetables, but it cannot replace them.

The various colors and varieties of fruits and vegetables provide a wide range of vitamins, minerals, fiber, enzymes, and phytochemicals that a single supplement or plant cannot match.

Natalie Butler, R.D., L.D. Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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