Chlorella vs. Spirulina: Which "Superfood" Algae Type Is Right for You? (2025)

Chlorella and spirulina are two types of nutrient-dense microalgae used as supplements. There is some evidence that both may support heart health, blood sugar control, and immune function. However, they differ in terms of cell structure and some aspects of nutritional value. The choice between the two depends on your unique needs and goals.

Nutritional Breakdown

The nutritional breakdown of chlorella and spirulina includes the following values for the servings:

Major Differences

While chlorella and spirulina both have impressive nutrient profiles, there are some significant differences between these two types of algae. They include the following:

• Chlorella is a single-cell green algae, while spirulina is a multicelled blue-green algae.
• Chlorella has a tougher cell wall, which may make it harder to digest than spirulina for people with digestive issues such as inflammatory bowel disease (IBS).
• Compared to chlorella, spirulina provides richer sources of vitamin E, vitamin K, vitamin B1, and biotin (vitamin B7).
  
• Chlorella and spirulina differ in the amounts of fat they contain. When compared, chlorella is higher in omega-3 fatty acids, while spirulina contains more omega-6 fatty acids.
• Chlorella contains more vitamin A than spirulina.

In addition, although both types of algae can help your body detox, research indicates that chlorella may be superior in supporting detoxification because it more effectively binds to and removes heavy metals and other harmful compounds, such as dioxin. It also supports liver function, which aids in removing impurities from your body.

Key Similarities

Research indicates that both chlorella and spirulina are superfoods that have the following key similarities:

• They may improve cardiovascular risk factors by improving blood lipid composition and blood pressure levels.
• They may boost exercise performance and support a healthy body weight.
• They may help improve anemia, immune function, and arterial stiffness.
• They are high in protein and contain a profile of all the required amino acids.
• Their benefits may improve insulin sensitivity and reduce blood glucose levels.
• They are nutrient-abundant sources of heart-healthy polyunsaturated fatty acids, especially omega-3 fatty acids, as well as vitamins and minerals.
  
• They are rich sources of phenolic compounds (compounds found in plants), or polyphenols, with antioxidant properties that neutralize harmful molecules called free radicals in your body to prevent cell damage in a process called oxidative stress.

Supplementing With Both at Once

Chlorella and spirulina can be taken separately or together, but it's considered safe to combine them.

These two microalgae may provide a complete protein source for people on plant-based diets.

When taking chlorella and spirulina together, you may benefit from starting one supplement before adding the second. This can help you determine the cause of any side effects that may arise.

Common side effects from these substances can include:

• Abdominal cramping
  
• Bloating
• Diarrhea
• Flatulence
• Green stools
• Nausea

Severe side effects may include:

• Allergic reactions such as asthma and anaphylaxis
  

Which Is Better for Your Health?

Chlorella and spirulina may benefit people seeking a good source of vitamins, minerals, antioxidants, and fatty acids. Neither is considered better than the other. Choosing one or the other depends on your current condition and your reasons for using algae to support your health goals.

Consult your healthcare provider before adding either substance to your diet to help you use one or both of these substances safely.

In some cases, it may be best to choose other supplement sources. Algae like chlorella and spirulina may not be safe for everyone.

People in the following groups should avoid using these substances:

• Pregnancy or breastfeeding: Harmful toxins in contaminated chlorella or spirulina may be transferred to a fetus during pregnancy or a breastfeeding infant.
• Children: Children have a higher sensitivity to chlorella and spirulina than adults.
• People with autoimmune diseases: This includes multiple sclerosis (MS), rheumatoid arthritis (RA), lupus (systemic lupus erythematosus, SLE), and others. Algae such as chlorella and spirulina may overstimulate the immune system, which could increase the symptoms of an autoimmune disease.
• People within two weeks of a scheduled surgery: Since chlorella and spirulina can lower blood sugar, they may interfere with blood sugar control during and after surgery.
  

How to Take Chlorella and Spirulina

Chlorella and spirulina are mainly sold as powder, tablets, extracts, capsules, or flakes.

Both types of algae are typically packaged as "dry" biomass in powdered form that is cold-pressed into tablets or filled into capsules.

While chlorella and spirulina are used as dietary supplements, they may be incorporated into the following:

• Bars (e.g., breakfast)
• Beverages
• Bread
• Cookies
• Crackers
• Muffins
• Pasta
• Pastry cream
• Smoothies
• Snacks
• Yogurt

There are no daily guidelines for a recommended amount of chlorella or spirulina.

However, the standard dosage for spirulina may include the following:

• Pediatric dosage: Not intended for use in children under age 18 without the advice of a healthcare provider
• Adult dosage: 1 to 10 grams daily for up to six months

Product contents vary. Limit your intake to the manufacturer's suggested dosage. Ask your pharmacist or healthcare provider any questions you may have.

Summary

Algae like chlorella and spirulina are nutrient-dense "superfoods" that are safe for most people to consume. They are both rich in vitamins, minerals, and antioxidants. While more research is needed, chlorella and spirulina have been linked to health benefits, such as better blood sugar control and a lower risk of heart disease.

While they may support better health, chlorella and spirulina may also pose a risk of adverse effects for certain people. To protect your well-being, contact your healthcare provider to discuss contraindications before you begin using one or both of these substances.