What Happens to Your Body When You Start Taking Spirulina?

October 4, 2025 •

3 min read

According to the World Health Organization, spirulina was deemed the "best food for the future" in 1996, recognizing its potent nutritional value. This blue-green algae is packed with protein, vitamins, minerals, and antioxidants, and understanding what happens to your body when you start taking spirulina can help you decide if it is the right supplement for your health goals.

Quick Summary

Taking spirulina introduces potent antioxidants like phycocyanin and a dense nutrient profile into your system. This can lead to reduced inflammation, improved cholesterol levels, enhanced immune function, and better athletic performance and energy over time.

Key Points

Antioxidant Power: The compound phycocyanin gives spirulina its blue color and provides strong antioxidant and anti-inflammatory properties, fighting oxidative stress and protecting cells.
Heart Health Improvements: Regular intake may lead to improved cholesterol levels (lower LDL, higher HDL) and reduced blood pressure due to its production of nitric oxide.
Enhanced Immunity: Spirulina strengthens the immune system by boosting the production of antibodies and the activity of immune cells like natural killer (NK) cells.
Energy and Endurance Boost: Its high protein and nutrient content, including B vitamins and iron, can increase overall vitality and improve muscle strength and endurance for athletes.
Detoxification Support: The algae helps bind and remove heavy metals from the body and supports liver and kidney function during detoxification processes.
Important Precautions: Spirulina can worsen autoimmune conditions, interfere with blood thinners, and must be avoided by those with PKU. Contamination is also a risk if not sourced from reputable suppliers.

A Nutritional Powerhouse

Spirulina is a cyanobacterium, often referred to as blue-green algae, that has been consumed for centuries. It is one of the most nutrient-dense foods available and comes in powder, tablet, and capsule forms. A single tablespoon of dried spirulina powder contains significant amounts of protein, B vitamins, iron, copper, and powerful antioxidants. Its protein content is high quality and includes all essential amino acids. This rich nutritional makeup contributes to the many health changes experienced with spirulina.

The Anti-inflammatory and Antioxidant Effect

Integrating spirulina into your diet can significantly enhance your body's antioxidant defenses. Its main active compound is phycocyanin, which gives it its blue-green color. Phycocyanin acts as a strong antioxidant, fighting oxidative stress caused by free radicals.

What is oxidative stress and why does it matter?

Oxidative stress, an imbalance of free radicals and antioxidants, can damage cells and DNA, leading to inflammation and contributing to chronic diseases. By inhibiting inflammatory molecules, phycocyanin provides notable antioxidant and anti-inflammatory benefits. Studies have indicated that spirulina can reduce oxidative damage, inflammation, and muscle damage caused by exercise.

Positive Changes for Heart Health

Spirulina has shown promise in improving various heart health markers.

Cholesterol Management: Research suggests that spirulina may help decrease total and LDL ('bad') cholesterol while potentially increasing HDL ('good') cholesterol.
Blood Pressure Reduction: Spirulina may help lower high blood pressure by increasing nitric oxide production, which relaxes and expands blood vessels.

Strengthening Your Immune System

Consistent spirulina consumption may benefit your immune system. It has been shown to boost immune function by increasing antibody production and enhancing the activity of immune cells, such as natural killer (NK) cells. This can help your body combat infections and potentially protect against certain diseases. The blend of vitamins, minerals, and bioactive compounds in spirulina contributes to these effects.

Increased Energy and Endurance

Individuals seeking increased energy and athletes looking to improve performance may find spirulina beneficial. Its dense nutrient profile, including protein and B vitamins, supports metabolism and helps maintain energy levels. Studies suggest it can enhance muscle strength, endurance, and oxygen uptake during exercise. This makes it a potential aid for improving athletic performance and recovery.

Comparison: Spirulina vs. Chlorella

Spirulina and Chlorella are both popular microalgae supplements with distinct characteristics.


Feature	Spirulina	Chlorella
Organism Type	Cyanobacterium (blue-green algae)	Single-celled algae
Appearance	Coiled, filamentous shape	Spherical shape
Color	Blue-green	Vibrant green (higher chlorophyll)
Protein Content	Slightly higher percentage (60-70%)	Slightly lower percentage (50-60%)
Cell Wall	Softer cell wall, easier to digest	Hard, indigestible cell wall; needs processing
Detox Capabilities	Binds to heavy metals, effective against arsenic	Superior at heavy metal chelation (mercury, lead)
Unique Compounds	Phycocyanin (antioxidant, anti-inflammatory)	Chlorophyll, Chlorella Growth Factor (CGF)
Nutrients	Rich in gamma-linolenic acid (GLA)	Higher in Vitamin A, D2, and chlorophyll

Potential Side Effects and Precautions

While generally safe, particularly when sourced from controlled environments, spirulina can have potential side effects. Consulting with a healthcare professional regarding appropriate usage can help minimize initial issues like gas or bloating. Due to the risk of contamination, it is essential to select reputable brands that test for heavy metals and toxins.

Autoimmune Conditions: Individuals with autoimmune diseases should avoid spirulina as it may exacerbate symptoms.
Blood Thinners: Spirulina can affect blood clotting and should be avoided by those on blood-thinning medications or with bleeding disorders.
Phenylketonuria (PKU): Spirulina contains phenylalanine and is not suitable for individuals with PKU.
Contamination Risk: Sourcing from certified brands is vital due to limited regulatory oversight.

Conclusion: A Natural Boost for Wellness

Incorporating spirulina into your routine can offer significant health benefits, from strengthening antioxidant defenses and supporting cardiovascular health to boosting immunity. Its anti-inflammatory properties and nutrient density may also enhance energy and athletic performance. However, it's important to consider proper usage and potential side effects, especially for those with certain health conditions or taking specific medications. Choosing a high-quality product from a trusted source is crucial for safety. Used mindfully, spirulina can be a valuable addition to a wellness plan, providing a natural, nutrient-rich health boost.

For further scientific details on spirulina's benefits, including neuroprotective effects, you can consult this detailed review: Beneficial Effects of Spirulina Consumption on Brain Health.

Frequently Asked Questions

While individual experiences can vary, some people report feeling the effects, such as increased vitality and energy, within a few weeks of consistent daily use. For cardiovascular markers like cholesterol, studies often measure effects over several months.

Spirulina contains a compound called 'pseudovitamin B12,' which is not effective in humans and cannot be relied upon as a source of this essential nutrient. This is a common misconception.

People with autoimmune diseases (e.g., lupus, rheumatoid arthritis), phenylketonuria (PKU), or bleeding disorders should avoid spirulina. It can also interact with blood-thinning, immunosuppressant, and diabetes medications.

Spirulina is available in powder, tablet, and capsule forms. Powder can be mixed into smoothies, juices, or yogurt, while tablets offer pre-measured convenience. Avoid heating or cooking it, as this can degrade its nutritional value.

While generally safe for healthy adults, its consumption is not recommended for individuals with specific health conditions, including pregnant or breastfeeding women without prior consultation with a doctor. Sourcing from a reputable brand to avoid contamination is also critical for safety.

Chlorella is considered a more powerful detoxifier for heavy metals like lead and mercury, primarily due to its unique cell wall structure. Spirulina, while also aiding in detoxification, is often easier on the digestive system and is particularly effective against arsenic.

Some research suggests that spirulina may aid in weight loss by potentially reducing appetite and increasing metabolism. However, more extensive studies are needed in this area.