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Discover chlorella benefits and potential chlorella side effects

As of 2004, an estimated 10 million people took chlorella worldwide.1 Some of the most popular uses include aiding weight loss and improving candida symptoms.


For hundreds of years, chlorella has been used as a food source and more recently as a supplement. Chlorella algae that is used for human ingestion is grown and cultivated in pools of fresh mineral water, making it easily available for use in supplement and food form.1

Chlorella definition: A single-cell green algae that grows in fresh water.1

Chlorella contains high levels of chlorophyll, beta carotene, and vitamin B12. As well, it has a large concentration of vitamins and minerals which can act as antioxidants to protect our bodies from harmful free radicals.1

There are claims of numerous health benefits of chlorella, making it a popular supplement used for a variety of conditions and in the prevention of certain diseases.

What is chlorella in terms of what it can do for your health? In this reviewwe’ll find out what chlorella can be used for and take a look at possible side effects. We’ll also review the nutritional value of chlorella and where you can purchase it.

Chlorella Benefits

Today, there have been numerous health benefits of chlorella investigated. Research and studies show that chlorella may be helpful in treating the following conditions.

Chlorella Weight Loss Benefits

For those wondering ‘does chlorella help with weight loss?’ there is some evidence that a hot water extract of chlorella may help users lose weight. Chlorella may be considered a useful weight loss supplement as it’s a complete protein and is nutrient rich. Research shows that chlorella may promote weight reduction by blocking fat cell production as well as reducing fat cells that are already present.2

Chlorella and Blood Pressure

Chlorella may help with hypertension as it contains calcium, potassium, and dietary fiber, beneficial nutrients that have been noted to help reduce hypertension naturally. Preliminary research has shown promising results for chlorella as a natural alternative treatment for moderate to high blood pressure.4

Chlorella for Candida

Candida is a fungus organism that is naturally found in the body. When the immune system is low or compromised, candida and yeast infections may occur. Supplementing with chlorella has been shown to have a natural immunostimulating effect on healthy individuals.5

In animal and in vitro studies, chlorella has been noted to have antiviral and antibacterial properties, which may further strengthen the body’s natural defences.5

Chlorella Hair Health

Chlorella may help prevent hair loss as well as promote hair growth due to the high levels of iron, vitamin b12 and beta carotene it contains. B vitamins are essential for supporting hair growth.6 Nutritional factors such as low iron levels have been associated with female hair loss.7 Beta carotene is part of the carotenoid family, which is a phytonutrient. 8 Phytonutrients may increase blood circulation in the scalp.

Chlorella as an Antioxidant

Research shows that chlorella may act as a potent antioxidant thanks to its high levels of vitamin C, vitamin E and chlorophyll. To test its antioxidant activity, a study was done using 52 participants who smoke, as smoking produces high levels of free radicals that attack healthy cells in the body. For six weeks, participants were given 6.3 g of chlorella daily. Research shows that antioxidant levels of vitamin C increased by 44.4% while vitamin E levels increased by 15.7%.9

Chlorella for Pregnancy

Some studies show that using chlorella during pregnancy, may reduce the side effects of anemia and edema (fluid retention). This may be because of the high levels of vitamin B12, iron, and magnesium found in chlorella.10

The benefits of chlorella powder and Chlorella nutrition facts

What is chlorella? Discover the health benefits of chlorella and the difference between chlorella and spirulina.

Chlorella Side Effects

Is chlorella safe to use? Chlorella appears to be safe to take as a supplement. Some people may experience gastrointestinal side effects when taking chlorella, nausea and vomiting being the most common complaints.

Can chlorella make you sick? When taken as directed, chlorella is non-toxic, but some people may be allergic to chlorella. Stop taking the supplement and call you doctor if you experience itchy skin or hives.11 Case reports of photosensitivity (increased sensitivity to the sun) have been noted.12 However, this is considered a rare side effect.

Studies show that taking chlorella while pregnant is safe, however consult with your doctor before taking the supplement.

Chlorella vs Spirulina

Chlorella and spirulina are similar in that they are algae found in fresh water.1 As well, they both have high levels of chlorophyll and other nutrients, such as beta carotene and vitamin C. However, Chlorella uses and nutrient profile are different from spirulina.13

Spirulina is marketed more for the amount of protein it provides while chlorella is used more as a supplement for CGF, chlorella growth factor. CGF is an extract found in chlorella that contains substances such as proteins, vitamins, and essential amino acids which may be capable of improving growth rate, boosting the immune system, and naturally alleviating hypertension.13

Chlorella Nutrition

Let’s take a look at some of the most important chlorella nutrition facts. How much of each of these nutrients you get will depend on chlorella dosage as well as the quality of the product. Yaeyama chlorella, grown and cultivated off the Japanese coral reef near Ishigaki Island, is marketed as one of the best sources of organic chlorella.

There are over 30 different classes of chlorella, however the two more common classes are Chlorella pyrenoidosa and Chlorella vulgaris. To be most beneficial, chlorella needs to be taken as supplement as it has a hard cell wall that can’t be digested by the human body. Look for broken cell wall chlorella to be sure your body can absorb it correctly.

Chlorella has an amino acid profile that’s comparable to eggs, and contains all the essential amino acids that humans require.14

How much protein in chlorella? Chlorella is made up of 70% protein by dry weight. It’s rich in amino acids and is considered a complete protein.14

Chlorella contains several B vitamins, as well as vitamin A. Magnesium in chlorella is also found in high levels, as is calcium and phosphorus.13,14

Depending on what type of chlorella supplement you’re taking, chlorella iron content is enough to provide you with up to 40% of the recommended daily value. High levels of vitamin C improve the absorption of iron.14

While nutrient values may range slightly (based on the chlorella sourced) per serving (2,500 mg) chlorella contains about 1500 mg of protein, 3.5 mg of iron, 20 mg of potassium, 1200 mcg of beta carotene and 500 IU of vitamin A.15

How Much Chlorella Per Day?

While the average dose of chlorella is 4 to 8 g per day, users are encouraged to start with 1 g per day and gradually increase your dosage. Avoid taking more than 8 gm per day as it may increase your chances of experiencing nausea or vomiting.

Chlorella is best taken in the morning to improve digestion during the day. Take capsules and tablets with a glass of water. For those wondering how to eat chlorella, many people like adding powder to a smoothie or acai bowl, as the chlorella taste can be quite strong.

Where to Buy Chlorella

Chlorella is sold as chlorella powder, chlorella tablets and capsules, or as an extract. To purchase chlorella, Amazon is a good online option. The supplement is also available in health food and grocery stores, as well as at Walmart. To get high quality chlorella, your best choice is organic chlorella powder and capsules.

Scientific Research Referenced in this Article

  1. Mason, R. (2001) Chlorella and Spirulina: Green Supplements for Balancing the Body. Alternative and Complementary Therapies, 7(3): 161-165. Retrieved on November 11, 2017 from https://doi.org/10.1089/107628001300303691
  2. Chon, JW. & Sung, JH. (2009) Chlorella methanol extract reduces lipid accumulation in and increases the number of apoptotic 3T3-L1 cells. Ann N Y Acad Sci. 1171, 183-9. doi: 1111/j.1749-6632.2009.04895.x.
  3. Mizoguchi, T. & Takehara, I. (2009) Nutrigenomic studies of effects of Chlorella on subjects with high-risk factors for lifestyle-related disease. J Med Food, 11(3): 395-404. DOI:1089/jmf.2006.0180
  4. Merchant, R. & Andre, C. (2004. Chlorella Supplementation for Controlling Hypertension: A Clinical Evaluation. Alternative and Complementary Therapies. 8(6): 370.376. Retrieved November 11, 2017 from http://online.liebertpub.com/doi/abs/10.1089/107628002761574680
  5. Kwak, JH. & Baek, SH. (2012) Beneficial immunostimulatory effect of short-term Chlorella supplementation. Nutr J., 11, 53. doi: 1186/1475-2891-11-53
  6. University of Maryland Medical Center. (2015, October 19). Vitamin B12 (cobalamin). Retrieved November 14, 2017 from http://www.umm.edu/health/medical/altmed/supplement/vitamin-b12-cobalamin
  7. Rushton, D. H. (2002). Nutritional factors and hair loss. Clinical and Experimental Dermatology27(5), 396-404. doi:1046/j.1365-2230.2002.01076.x
  8. Evans, J. & Johnson, E. (2010) The Role of Phytonutrients in Skin Health. Nutrients. 2(8): 903-928. Retrieved on November 11, 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257702/
  9. Lee, SH. & Lee, HJ. (2010) Six-week supplementation with Chlorella has favorable impact on antioxidant status in Korean male smokers. Nutrition. 26(2): 175-83. Retrieved on November 11, 2017 from https://www.ncbi.nlm.nih.gov/pubmed/19660910
  10. Nakano, S. & Takekoshi, H. (2010) Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant women. Plant Foods Hum Nutr. 65(1): 25-30. Retrieved on November 11, 2017 from https://www.ncbi.nlm.nih.gov/pubmed/20013055
  11. Azocar, J. & Diaz, A. (2013) Efficacy and safety of Chlorella supplementation in adults with chronic hepatitis C virus infection. World J Gastroenterol, 19(7), 1085-1090. doi: 3748/wjg.v19.i7.1085.
  12. Jitsukawa, K., Suizu, R., & Hidano, A. (1984). Chlorella Photosensitization. International Journal of Dermatology23(4), 263-268. doi:1111/j.1365-4362.1984.tb01245.x
  13. Kent, M. & Welladsen, H. (2013) Nutritional Evaluation of Australian Microalgae as Potential Human Health Supplements. Retrieved on November 11, 2017 from http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118985#
  14. Wells, M. & Philippe, P. (2017) Algae as nutritional and functional food sources: revisiting our understanding. J Appl Phycol. 29(2): 949-982. Retrieved on November 11, 2017 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5387034/
  15. Vega. (n.d.). Vega chlorella. Retrieved November 15, 2017 from – View Reference