Chlorella vs Spirulina

Written by: Pard Bharaj



Time to read 16 min

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Author: Pard Bharaj

I am a dedicated researcher with nearly a decade of experience in investigating health best practices. 

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Disclaimer: The information provided in this article is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or before making any changes to your diet or lifestyle, especially if you have existing health conditions.


Chlorella and Spirulina are rightly regarded as two of the most powerful superfoods available today, each offering a wide range of health benefits. While both are excellent for detoxification, they also have unique properties that make them suitable for different health needs. This article will help you understand the key differences and benefits of Chlorella and Spirulina, guiding you on which superfood might be the best fit for your specific health goals. 

Origin and Cultivation of Chlorella and Spirulina:

  • Chlorella is a green algae that has existed for over 2 billion years, it was discovered in 1890 by Dutch microbiologist Dr. Martinus Beijerinck. It is well known for having the highest chlorophyll content of any foods, Chlorella gained attention post-World War II for its potential as a primary food source due to its high protein content. Cultivated in freshwater environments, Chlorella requires sunlight, clean water, and carbon dioxide. It is grown in controlled ponds to ensure purity, harvested, dried, and processed by breaking its tough cell walls to enhance digestibility and nutrient absorption.

  • Spirulina is a blue-green algae, scientifically a cyanobacteria, consumed for centuries, notably by the Aztecs and the Kanembu people around Lake Chad. It does well in warm, alkaline lakes and was recognised for its nutritional value and potential to address malnutrition. Cultivated in man-made ponds or raceway systems, Spirulina requires warm, alkaline water and ample sunlight. The cultivation process involves circulating water for even exposure to light and nutrients. After harvesting, Spirulina is filtered, dried, and processed into powder or tablets, without the need for breaking cell walls.

Chlorella vs Spirulina Nutritional Face-off:

In this section, we will explore the protein content, as well as the main vitamins, minerals, and antioxidants present in Chlorella and Spirulina. Please note that these nutrients can vary significantly depending on growing conditions.

1. Protein Content Comparison:

  • Chlorella: Chlorella is an excellent source of protein, comprising about 55-60% of its dry weight. It contains all essential amino acids, making it a complete protein source. This high protein content supports muscle growth, repair, and overall bodily functions.
  • Spirulina: Spirulina slightly edges out Chlorella in protein content, with 60-70% protein by dry weight. It also contains all essential amino acids, and is particularly rich in leucine, isoleucine, and valine, which are vital for muscle metabolism and repair. Spirulina‚Äôs easily digestible protein makes it an ideal supplement for athletes and individuals looking to boost their protein intake.

2. Vitamin Comparison 


  • Vitamin A (Beta-Carotene): Rich in beta-carotene, which the body converts into vitamin A, essential for vision, immune function, and skin health.

  • Vitamin C: High levels of vitamin C, which supports immune function, skin health, and acts as a powerful antioxidant.

  • Vitamin E: Contains significant amounts of vitamin E, an antioxidant that protects cells from oxidative damage.

  • B Vitamins: Provides a good amount of B vitamins, including B1, B2, B6, and B12, which are essential for energy production and overall metabolic function. Notably, it contains more active forms of vitamin B12.


  • Vitamin A (Beta-Carotene): Exceptionally rich in beta-carotene, more so than many other foods, supporting vision and immune function.

  • Vitamin K: Contains vitamin K, which is important for blood clotting and bone health.

  • Vitamin B12: Spirulina provides vitamin B12, but it maybe mostly in inactive forms (pseudovitamin B12), which are not as beneficial as the active forms found in chlorella.

  • Vitamin E: Rich in vitamin E, which acts as an antioxidant and protects cells from damage.

  • Riboflavin (Vitamin B2) and Niacin (Vitamin B3): Higher levels compared to chlorella, supporting energy metabolism and overall cellular function.

3. Mineral Comparison:


  • Iron: Chlorella is particularly rich in iron, with levels ranging around 79 mg per 100g, crucial for red blood cell production and oxygen transport.

  • Magnesium: High in magnesium, typically 200 to 300 mg per 100g, supporting muscle and nerve function, as well as energy production.

  • Zinc : Contains significant amounts of zinc, ranging from 10 to 20 mg per 100g, which supports the immune system and wound healing.

  • Phosphorus: Provides phosphorus, generally around 100 to 200 mg per 100g, necessary for the formation of bones and teeth and for energy production.


  • Calcium: Spirulina is particularly rich in calcium, with levels ranging from 100 to 200 mg per 100g, which is essential for bone health and muscle function.

  • Iron: Also high in iron, typically around 30 mg per 100g, supporting red blood cell production and oxygen transport.

  • Magnesium: Contains magnesium, usually around 200 to 300 mg per 100g, necessary for muscle and nerve function.

  • Potassium: Rich in potassium, ranging from 1000 to 1500 mg per 100g, which is vital for maintaining proper fluid balance, nerve function, and muscle contractions.

  • Selenium: Contains selenium, generally around 0.02 to 0.05 mg per 100g, an antioxidant mineral that supports immune function and protects cells from damage.

4. Antioxidants and Phytonutrients:


  • Chlorophyll: Chlorella is exceptionally rich in chlorophyll (with levels often around 3-5% of its dry weight), which acts as a powerful antioxidant and supports detoxification by binding to toxins and aiding in their elimination from the body.

  • Lutein: This carotenoid is present in chlorella and helps protect the eyes from oxidative damage, supporting eye health.

  • Chlorella Growth Factor (CGF): Unique to chlorella, CGF is rich in nucleic acids (RNA and DNA) and promotes cell repair and regeneration.

  • Beta-Carotene: As a precursor to vitamin A, beta-carotene in chlorella acts as an antioxidant and supports skin and eye health.

  • Polyphenols: Chlorella contains various polyphenols, which are compounds with strong antioxidant properties that help protect against cellular damage and support overall health.


  • Chlorophyll Content: Spirulina also contains a substantial amount of chlorophyll, typically around 1-2% of its dry weight. While this is less than chlorella, it still provides significant health benefits, including supporting detoxification and acting as an antioxidant.

  • Phycocyanin: A unique blue pigment found in spirulina, phycocyanin is a powerful antioxidant with anti-inflammatory properties.

  • Beta-Carotene: Spirulina is extremely rich in beta-carotene, providing strong antioxidant protection and supporting vision and immune function.

  • Superoxide Dismutase (SOD): Spirulina contains this enzyme, which acts as a potent antioxidant protecting cells from damage by superoxide radicals.

  • Gamma-Linolenic Acid (GLA): An omega-6 fatty acid found in spirulina, GLA has anti-inflammatory and antioxidant properties.

  • Polysaccharides: Spirulina contains polysaccharides that can stimulate the immune system and provide antioxidant benefits.

  • Polyphenols: These compounds in spirulina contribute to its antioxidant capacity and provide additional health benefits.

chlorella vs spirulina: nutrients comparison table

Chlorella vs Spirulina Health Benefits:

Both Chlorella and Spirulina offer numerous health benefits, but their effects can vary depending on their unique nutritional profiles. Here’s a comparison of their benefits in terms of detoxification, immune system support, digestive health, energy, and liver health.

1. Detoxification:


  • Detoxification:¬†Chlorella is renowned for its ability to detoxify toxins from the body, as well as heavy metals. Its high chlorophyll content also acts as a natural detoxifier, helping to eliminate harmful toxins.

  • Radiation Detox: Chlorella has been shown to help the body eliminate radioactive particles, making it useful for people undergoing radiation therapy or exposed to environmental radiation.

  • Liver Support: Chlorella supports liver health by reducing liver inflammation and improving liver function. Its detoxifying properties help remove toxins from the liver, promoting overall liver health. Studies have indicated that Chlorella can help reduce liver enzymes, a marker of liver damage, and support the regeneration of liver cells.


  • General Detoxification: Spirulina also has impressive detoxifying properties, and also contains significant amounts of Chlorophyll although not as much as Chlorella. It can bind to heavy metals and assist in their removal from the body. It is also high in Polysaccharides which can support detoxification.

  • Liver Support: Spirulina supports liver health by reducing oxidative stress and inflammation. The high antioxidant content, particularly phycocyanin, helps protect liver cells from damage. Spirulina can also reduce liver fat and improve lipid profiles (although Chlorella has been shown to be more effective for this), which are beneficial for individuals with fatty liver disease.

2. Immune System Support:


  • Immune Enhancement: Chlorella boosts the immune system by increasing the activity of T-cells and macrophages, which are critical for defending the body against infections. The Chlorella Growth Factor (CGF) also plays a role in enhancing immune function. Additionally, Chlorella supports liver health, brain health, heart health, blood sugar control, and contains anti-cancer compounds, making it a comprehensive supplement for overall good health.


  • Immune Support: Spirulina is highly effective in supporting the immune system due to its high phycocyanin content. Phycocyanin has been shown to stimulate the production of white blood cells and antibodies, enhancing the body's ability to fight off infections. Spirulina also supports liver health, brain health, heart health, blood sugar control, and contains anti-cancer compounds, providing a wide range of health benefits.

3. Digestive Health Benefits:


  • Digestive Aid:¬†Chlorella‚Äôs high fibre content supports healthy digestion by promoting regular bowel movements and preventing constipation. The fibre also acts as a prebiotic, feeding beneficial gut bacteria and improving gut health overall.

  • Gut Flora Balance:¬†Chlorella helps balance the gut microbiome, which is essential for overall digestive health and nutrient absorption. In studies it has shown that it could also potentially have benefits for people with gastrointestinal diseases.


  • Digestive Support: Although Spirulina contains less fibre than Chlorella, it still supports digestive health. Spirulina‚Äôs high protein content can aid in maintaining a healthy gut lining and reducing gut inflammation.

  • Probiotic Effects: Spirulina has been shown to have probiotic effects, promoting the growth of beneficial gut bacteria which can enhance digestion and nutrient absorption.

4. Energy and Endurance Boost:


  • Sustained Energy:¬†Chlorella provides a steady release of energy due to its balanced nutrient profile, including a good mix of proteins, vitamins, and minerals. This can help sustain energy levels throughout the day without the peaks and crashes associated with sugary foods.

  • Cellular Energy:¬†The high chlorophyll content supports oxygen transportation in the blood, which may improve overall energy levels.


  • Immediate Energy Boost: Spirulina is particularly effective for an immediate energy boost. Its high protein content, combined with its rich B-vitamin profile, helps convert food into usable energy efficiently. This makes it an excellent supplement for athletes and those needing a quick energy boost.

  • Endurance and Stamina:¬†Spirulina has been shown to enhance endurance and reduce fatigue. Its high antioxidant levels help reduce muscle damage and improve recovery times, making it ideal for those engaging in regular physical activity.

5. Mitochondrial Support:

Mitochondria are the powerhouses of cells, responsible for producing the energy needed for cellular functions. Supporting mitochondrial health is crucial for overall vitality, energy levels, and efficiency of cells.


  • Mitochondrial Health:¬†Chlorella‚Äôs rich nutrient profile, including its high levels of antioxidants and chlorophyll, supports mitochondrial health by protecting these cellular powerhouses from oxidative damage. Healthy mitochondria are crucial for energy production, and Chlorella‚Äôs detoxifying properties further ensure a clean cellular environment, reducing the toxic load that can impair mitochondrial function.


  • Mitochondrial Function: Spirulina is particularly beneficial for mitochondrial health due to its high content of phycocyanin and superoxide dismutase (SOD). These powerful antioxidants protect mitochondria from oxidative stress, thereby enhancing their function and efficiency. Spirulina also contains essential fatty acids like gamma-linolenic acid (GLA), which support mitochondrial membranes and energy production processes.

Potential Side Effects and Considerations:


  • Digestive Issues: Some people may experience digestive issues such as gas, bloating, when first introducing Chlorella into their diet. This is often due to its high fibre content.

  • Allergic Reactions: Although rare, some individuals may have allergic reactions to Chlorella.

  • Quality and Purity: Ensure you purchase Chlorella from reputable sources to avoid contamination. Look for products that are tested for purity and quality.

  • Gradual Introduction: Start with a small dose and gradually increase it to allow your body to adjust and minimise potential side effects.

  • Medical Conditions: Individuals with autoimmune diseases or those taking immunosuppressive drugs should consult their healthcare provider before taking Chlorella, as it can stimulate the immune system.


  • Digestive Issues: Similar to Chlorella, Spirulina can cause digestive discomfort such as nausea, gas, and diarrhoea in some individuals, especially when first introduced.

  • Allergic Reactions: Allergic reactions to Spirulina are rare but possible.

  • Quality and Purity: Choose Spirulina products from trusted brands that conduct rigorous testing for contaminants. This ensures the product is safe and free from harmful substances. Spirulina, being, has a higher risk of contamination from heavy metals, microcystins (toxins produced by certain algae), and harmful bacteria if not sourced and processed properly.

  • Gradual Introduction: Start with a lower dose and gradually increase it to help your body acclimate and reduce the risk of digestive upset.

  • Medical Conditions: Individuals with phenylketonuria (PKU) should avoid Spirulina, as it contains phenylalanine, an amino acid that they cannot metabolise. Those with autoimmune diseases should also consult a healthcare provider before use, due to its immune-stimulating properties.

Chlorella vs Spirulina: Which One Is Better?

Choosing between Chlorella and Spirulina depends on your individual health goals and nutritional needs. Chlorella is particularly effective for detoxification, thanks to its high chlorophyll content, which helps eliminate heavy metals and toxins. It also supports liver health, provides a substantial nutrient boost, especially in iron and vitamin B12, and enhances immune function. Spirulina, on the other hand, is also good for detoxification, excels in boosting energy and endurance due to its high protein content and rich array of antioxidants like phycocyanin. It supports immune health, protects liver function, and helps regulate blood sugar levels.

Using both together can create a synergistic effect, and provide a comprehensive nutritional profile that covers a broad range of essential nutrients. This combination enhances the body’s natural detoxification processes, promotes immune function, and ensures better overall energy and vitality.However, if you had to choose just one, Chlorella might provide slightly more overall health benefits due to its detoxification capabilities and broader nutrient profile, but only just slightly.

References and Further Reading:

1. The Long-Term Algae Extract (Chlorella and Fucus sp) and Aminosulphurate Supplementation Modulate SOD-1 Activity and Decrease Heavy Metals (Hg++, Sn) Levels in Patients with Long-Term Dental Titanium Implants and Amalgam Fillings Restorations

This study investigated the effects of long-term supplementation with Chlorella and Fucus extracts, along with aminosulphurates, on heavy metal detoxification in patients with long-term dental titanium implants and amalgam fillings. Over 90 days, the supplementation significantly reduced levels of mercury (Hg++), silver (Ag), tin (Sn), and lead (Pb) in the participants. Additionally, the supplementation improved antioxidant activity, as evidenced by decreased SuperOxide Dismutase-1 (SOD-1) activity compared to baseline levels.

Publication details: The study was published in the journal Antioxidants on 16 April 2019. Authors include Jos√© Joaqu√≠n Merino, Jos√© Mar√≠a Parmigiani-Izquierdo, Adolfo Toledano Gasca, and Mar√≠a Eugenia Caba√Īa-Mu√Īoz.

2. Effect of chlorella vulgaris vs. spirulina supplementation on lipid profile and liver function in patients with nonalcoholic fatty liver disease: a randomised controlled trial

A study published in the International Journal of Probiotics and Prebiotics examined the effects of Chlorella Vulgaris and Spirulina on lipid profiles and liver function in NAFLD patients. Over eight weeks, 66 patients were divided into groups receiving either Chlorella or Spirulina, with a control group receiving no supplements. Both supplements significantly reduced weight, but Chlorella was more effective in improving liver function and lipid profiles, particularly by reducing ALT levels.

Publication Details: Maryam Chitsaz, Hassan Mozaffari-Khosravi, Hassan Salman-Roghani, Javad Zavar-Reza, and Mohammadhassan Lotfi, International Journal of Probiotics and Prebiotics, Vol. 11, No. 3/4, 2016.

3. Nutritional Supplementation with Chlorella pyrenoidosa Lowers Serum Methylmalonic Acid in Vegans and Vegetarians with a Suspected Vitamin B‚āĀ‚āā Deficiency

A study in the Journal of Medicinal Food found that daily supplementation with 9 grams of Chlorella pyrenoidosa significantly reduced serum methylmalonic acid levels by an average of 34% in vegans and vegetarians with vitamin B12 deficiency, suggesting that Chlorella is a bioavailable source of B12.

Publication Details: Randall Edward Merchant, Todd W. Phillips, Jay Udani, Journal of Medicinal Food, October 2015

4. Vitamin B-12 from algae appears not to be bioavailable

A study in the American Journal of Clinical Nutrition found that while plasma vitamin B12 levels increased in children consuming algae (nori and spirulina), their mean corpuscular volume (MCV) worsened, indicating poor bioavailability of B12 from these sources. Conversely, MCV improved in children consuming fish or B12 supplements, suggesting algae and plant foods are unreliable B12 sources.

Publication Details: P.C. Dagnelie, W.A. van Staveren, H. van den Berg, American Journal of Clinical Nutrition, March 1991

5. Effect of Spirulina (Arthrospira platensis) Supplementation on Physical 

The study found that adding spirulina significantly increased the protein content, particularly essential amino acids like lysine, and improved the fibre content of the pasta.

6. Trends and Technological Advancements in the Possible Food Applications of Spirulina and Their Health Benefits: A Review

The study reviews the nutritional value and potential applications of spirulina, highlighting its high protein content (60-70%) and rich profile of essential amino acids, including lysine, which is often lacking in plant-based diets. Spirulina also contains vitamins, minerals, and essential fatty acids like omega-3 and omega-6. Its significant bioactive compounds, such as phenols, phycocyanin pigment, and polysaccharides, contribute to its antioxidant and anti-inflammatory properties.

Publication Details: AlFadhly, N.K.Z.; Alhelfi, N.; Altemimi, A.B.; Verma, D.K.; Cacciola, F.; Narayanankutty, A. Molecules, University of Basrah, 2022.

7. Potential of Chlorella as a Dietary Supplement to Promote Human Health

The study highlights Chlorella’s rich nutrient profile, including high-quality protein, dietary fibers, polyunsaturated fatty acids, and vitamins such as D2 and B12. It reports various health benefits, including immunomodulation, antioxidative activity, and effects against diabetes, hypertension, and hyperlipidemia. The synergistic effects of these nutrients and antioxidants contribute to these benefits.

Publication details: Tomohiro Bito, Eri Okumura, Masaki Fujishima, and Fumio Watanabe. Nutrients, 2020, Tottori University and Sun Chlorella Corporation, Japan.

8. Chlorella diet alters mitochondrial cardiolipin contents differentially in organs of Danio rerio analyzed by a lipidomics approach

The study investigated the effects of a Chlorella diet on mitochondrial cardiolipin content in zebrafish. It found that Chlorella supplementation altered the cardiolipin profile, increasing the chain length of cardiolipin in larval fish and affecting the distribution of cardiolipin species in various adult organs. These changes suggest that dietary Chlorella can influence mitochondrial function by modifying lipid composition.

Publication details: The study was conducted by Yu-Jen Chao, Wen-Hsin Wu, Maria Balazova, Ting-Yuan Wu, Jamie Lin, Yi-Wen Liu, and Yuan-Hao Howard Hsu from Tunghai University and the Slovak Academy of Sciences, and published in PLOS ONE in March 2018.

9. Restoration of mitochondrial function by Spirulina polysaccharide via upregulated SOD2 in aging fibroblasts

The study investigated the effects of Spirulina polysaccharide complex (SPC) on mitochondrial function and aging in fibroblasts. It found that SPC upregulates superoxide dismutase 2 (SOD2), restoring mitochondrial function and collagen production while reducing oxidative stress without inducing inflammation. This suggests SPC has significant anti-aging potential by enhancing mitochondrial health and cellular function.

Publication details: Kayo Machihara, Shoma Oki, Yuka Maejima, et al., Kochi University and DIC Corporation, published in iScience, July 2023

10. Spirulina platensis Improves Mitochondrial Function Impaired by Elevated Oxidative Stress 

The study examined the effects of Spirulina platensis on horses with equine metabolic syndrome (EMS). It found that Spirulina improved mitochondrial function, reduced oxidative stress, and enhanced insulin sensitivity in these horses, leading to better cellular health and weight reduction.

Publication details: Daria Nawrocka, Katarzyna Kornicka, Agnieszka Ňömieszek, and Krzysztof Marycz, Marine Drugs, University of Environmental and Life Sciences, Wroclaw, Poland, 2017.

11. Spirulina polysaccharide-based prebiotic foods preparations-a promising approach for modulating gut microbiota and improving health

The study investigates the immunomodulatory and anti-inflammatory effects of Spirulina polysaccharides, highlighting their potential to enhance gut microbiota diversity and promote overall health. Spirulina polysaccharides were shown to reduce inflammation, regulate immune responses, and improve gut health by altering gut microbiota composition and increasing beneficial metabolites like short-chain fatty acids.

Publication details: Authors: F. Guan, G. Fu, Y. Ma, L. Zhou, G. Li, C. Sun, and T. Zhang. Journal of Functional Foods, 2024, Affiliated Hospital of Zunyi Medical University.

12. Assessing the impact of chlorella phenolic-rich extract on gastrointestinal health and function:

Therapeutic Potential of Chlorella Extract: Chlorella phenolic-rich extract has shown promise in modulating gut microbiota and reducing inflammation and oxidative stress, potentially improving symptoms of gastrointestinal conditions like ulcerative colitis and irritable bowel syndrome, as well as lowering liver enzyme levels and H. pylori infection rates. 

13. Chlorella vulgaris Modulates Gut Microbiota and Induces Regulatory T Cells to Alleviate Colitis in Mice:

The study investigates the immune regulatory effects of Chlorella vulgaris (C. vulgaris) and its influence on gut microbiota. It demonstrates that C. vulgaris supplementation can expand the regulatory T cell (Treg) population and alter gut microbiota composition, increasing short-chain fatty acid (SCFA) production in mice. Further, in a colitis model, C. vulgaris treatment reduced colitis symptoms and increased Treg levels, suggesting its potential as a safe supplement for managing inflammatory bowel disease (IBD) through modulating host-microbiome interactions.

14. Spirulina in Clinical Practice: Evidence-Based Human Applications

The study reviews various clinical applications of Spirulina, highlighting its potential health benefits. Spirulina has been shown to modulate immune functions, exhibit anti-inflammatory properties, and possibly have anticancer, antiviral, and antiallergic effects. It also shows promise in lowering cholesterol and managing diabetes, though larger studies are needed. Additionally, Spirulina may be effective in treating chronic arsenic poisoning and improving antioxidant status.

Publication details:  P. D. Karkos, S. C. Leong, C. D. Karkos, N. Sivaji, D. A. Assimakopoulos. Evidence-Based Complementary and Alternative Medicine, Liverpool University Hospitals, 2011.

15. Antioxidant, Immunomodulating, and Microbial-Modulating Activities of the Sustainable and Ecofriendly Spirulina


The study highlights Spirulina's antioxidant, anti-inflammatory, and immunomodulating properties. It also shows potential in modulating gut microbiota and supporting the growth of beneficial bacteria.

Publication details: Alberto Finamore, Maura Palmery, Sarra Bensehaila, Ilaria Peluso, Oxidative Medicine and Cellular Longevity, January 2017.

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