Spirulina: Benefits, Side Effects & Dosage


What is Spirulina?

You’ve probably never heard of it, but this blue-green microalgae is one of the oldest forms of life on Earth. Initially scientists classified it as a plant, but later placed it in the bacteria kingdom because of its biochemical properties. Spirulina is, in fact, a free-floating microalgae with unusually high nutritional values. It offers a high protein content and is rich in vitamins, minerals, essential fatty acids and other nutrients (x).

NASA conducted studies on spirulina and acknowledged its exorbitantly high nutrient profile — specifically, it contains a high protein efficiency ratio. More importantly, it contains 19 of the 22 amino acids the body needs for easy digestion. Needless to say, modern science has acknowledged spirulina as an excellent source of micronutrients. Relevant studies determined that spirulina offers a rich source of beta-carotene and has the capacity to cure a variety of problems related to the cardiovascular system. It can help alleviate allergies, control diabetes and strengthen the immune system (x).

As one of the most nutrient-dense foods on the planet, it’s rich in Vitamin B12, iron, magnesium, beta-carotene and gamma-linolenic acid (x). In other words, spirulina is a vital source of balanced nutrition. It contains all eight essential amino acids and even more calcium than milk. It is nearly 70 percent protein by weight, which is more than beef, chicken and soybeans (x, x).

What Does it Come From?

Spirulina grows in freshwater alkaline lakes, often near volcanoes. It grows abundantly in the tropical waters of Mexico, Central Africa and east Africa. Historically, Aztec civilizations used it for food. It consists of unicellular organisms that rely on water, minerals and warmth to produce protein, carbohydrates, vitamins and other vital nutrients (x, x).

Benefits of Spirulina


Accessing adequate protein is much more challenging for those living in poverty in developing countries. Spirulina is well recognized as a health supplement and more importantly, it may help combat malnutrition in developing countries. A number of studies have looked at the effects of spirulina supplementation in malnourished populations and in developing countries with high poverty rates (x).


Oxidative stress can lead to heart failure, high blood pressure, inflammation in the heart and plaque buildup in artery walls (atherosclerosis), which can cause heart attacks. Spirulina may specifically activate antioxidant enzymes to stop free radicals from damaging cell membranes. Studies show that it may counteract pollutants, such as arsenic, fluoride, iron, lead and mercury (x, x).


Spirulina can help maintain a healthy immune system. It prevents damage to major muscles by stimulating antibody production and stopping inflammatory responses from the immune system. Inflammation can lead to chronic diseases such as cancer, heart disease and multiple sclerosis (x).


One study analyzed the effects of spirulina in subjects who consumed a diet high in cholesterol. The results concluded that it may help lower cholesterol. Additionally, it significantly lowered the thickness of the aorta surface by as much as 48.3 percent. In fact, spirulina remarkably decreased the “bad cholesterol” by as much as 41.2 percent. This means that spirulina may be able to reduce risk factors for heart disease (x).


Last but not least, studies report that spirulina may be able to lower blood sugar, which is highly beneficial for individuals with diabetes. People with diabetes tend to have high levels of “bad cholesterol” and triglycerides, which increase the risk of cardiovascular disease. In studies, spirulina lowered blood sugar levels in diabetic patients and stimulated the body’s insulin function (x). Spirulina may be an effective natural supplement to manage diabetes (x).

Other Benefits

In addition to the incredible benefits listed above, the algae may also improve allergy symptoms, may be effective against anemia and could improve muscle strength and endurance. It may also help with weight loss without losing nutrition (x, x, x, x).

Spirulina Benefits

Spirulina Side Effects

The Food and Drug Administration (FDA) does not regulate spirulina, but it does not cause any significant side effects (x). Some side effects associated with spirulina include headaches, allergic reactions, muscle pain, sweating and insomnia.

Women who are pregnant or breastfeeding should not take spirulina. Those with a seafood allergy and patients with a thyroid condition, an autoimmune disorder, gout, kidney stones or phenylketonuria should avoid it as well. Always consult a doctor or pharmacist before taking this supplement or any others (x).

Dosage and Instructions

The general dosage for spirulina as a dietary supplement is 7 g every day. However, it is always best to consult with a healthcare professional first for the proper dosage.

Why Take Spirulina?

Because of the number of bioactive compounds it contains, in addition to all of the essential amino acids required for human health, spirulina is an amazing superfood. It is present in many natural foods, beverages and energy bars. But supplements are a great way to make sure the body receives all the nutrients it needs.

The Bottom Line

Spirulina offers tremendous health benefits and NASA recognizes and acknowledges it as a sustainable food source. Supplementing with it may improve cholesterol level, combat oxidative stress that causes inflammation and manage blood sugar levels to help control diabetes. It is also beneficial to cardiovascular health because it reduces cholesterol and lowers blood pressure. It may also benefit other disorders like anemia and insomnia. Spirulina is generally safe and may cause only a few mild side effects. However, it is not an adequate replacement for any medical treatment plan.

About the author

Chelsey Erwin

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