Spirulina Protein Per 100g – Complete Nutrition Guide
Discover Spirulina protein per 100g, its complete amino acid profile, key nutrients, and how this blue-green algae supports energy, anemia, and antioxidant defense.
Spirulina Protein Per 100g: Why It Matters
Spirulina is one of the richest food sources known to man, and its extraordinary protein density is a major reason why. Dried Spirulina powder is approximately 57% protein by composition — some analyses place it within the 50–70% range of dry weight — making Spirulina protein per 100g one of the most concentrated plant-based protein sources available. In a reference amount of 100 g, dried Spirulina supplies roughly 57 grams of protein along with 290 kilocalories, 24% carbohydrates, 8% fat, and 5% water.
What makes Spirulina protein per 100g especially notable is that Spirulina is considered a complete protein, containing all the essential amino acids: phenylalanine, leucine, valine, tryptophan, threonine, lysine, isoleucine, and methionine. The amino acid profile also shows high levels of alanine, glycine, and glutamic acid per 100 g of protein. This complete amino acid composition distinguishes Spirulina from many other plant-based protein sources.
Beyond protein, Spirulina is a rich source of B vitamins (thiamin, riboflavin, and niacin), dietary minerals such as iron and manganese, beta-carotene, gamma-linolenic acid (GLA), calcium, magnesium, potassium, zinc, and bioflavonoids. The World Health Organization has used Spirulina to feed malnourished children in India, underscoring its credentials as a powerhouse whole-food nutrient source.
A Protein Source with Thousands of Years of Use
Spirulina is a blue-green algae (cyanobacterium) commonly found in alkaline lakes and ponds in tropical and subtropical regions. It has been a valuable food source for Mexicans, Asians, and Africans for thousands of years. In Mexico circa 1300 AD, the Aztecs harvested Spirulina from Lake Texcoco and sun-dried it into cakes called tecuitlatl, which they ate with tortillas or toasted corn — sometimes combined with chiles and tomatoes to make a sauce.
In Africa, the Kanembu people of Chad have harvested Spirulina from Lake Chad and processed it into cakes known locally as "dihe" for use in sauces for meat and fish, a tradition that may date back to the ninth-century Kanem Empire. This practice remains an important part of their local economy today.
Modern scientific interest in Spirulina began in the 1970s when French researchers, particularly Dr. Clément, became interested in its high protein content. This protein research drew the attention of the scientific world and marked the beginning of large-scale Spirulina production in the late 1970s. Today, Limnospira platensis (formerly Arthrospira platensis) is the most widely cultivated species and has held GRAS (Generally Recognized as Safe) status from the FDA since 2003.
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Who Benefits from Spirulina's High Protein Content?
Given that Spirulina protein per 100g rivals or exceeds many conventional protein sources while delivering a complete amino acid profile, Spirulina may appeal to a wide range of individuals. Those seeking a whole-food alternative to isolated vitamins and minerals may find Spirulina's nutrient density particularly attractive, as it contains vegetable protein, beta-carotene, iron, trace minerals, and GLA in a single food.
Research suggests Spirulina supplementation may support individuals concerned with anemia and iron-deficiency fatigue, as clinical trials show improvements in hemoglobin and serum iron levels. Studies also indicate benefits for those interested in antioxidant defense, with human intervention trials confirming improvements in antioxidant status markers.
Athletes and physically active individuals may benefit from Spirulina's ergogenic potential — a systematic review of 13 controlled trials found Spirulina demonstrates benefits during submaximal exercise, including increased oxygen uptake and improved exercise tolerance. Older adults seeking nutritional support for healthy aging may also find value, as RCTs have demonstrated reductions in oxidative stress markers and improvements in immune function in elderly populations.
This product is dairy free, soy free, and grain free, making it accessible to individuals with common dietary sensitivities. However, like all protein-rich foods, Spirulina contains the essential amino acid phenylalanine (2.6–4.1 g/100 g), which should be avoided by people who have phenylketonuria. Spirulina should also be used with caution by people with autoimmune conditions or who are at risk of hypoglycemia or hypotension.
How to Take Spirulina
Take one (1) tablet, six (6) times daily with meals. Store in a cool, dry place and away from direct light. Each serving provides 500 mg of Spirulina per tablet. The product contains 100 tablets.
In the broader research literature, Spirulina is usually dosed in the range of 2 to 10 grams daily in whole powder or capsule form. Higher doses in the range of 4 to 10 grams daily appear to be most effective for improving lipid profiles, while a lower dose of 2 grams daily may help reduce symptoms of allergic rhinitis. A safe upper limit of 10 grams per day is commonly cited, and most studies showing benefits use doses at or below this level.
The most commonly reported side effects in clinical studies include gastrointestinal upset (e.g., abdominal cramps, nausea), fatigue, dizziness, and headache, though Spirulina is generally considered safe and well-tolerated.
Written by Greg Howlett
Frequently asked questions
How much protein does Spirulina have per 100g?
Dried Spirulina powder contains approximately 57 grams of protein per 100 g, though the protein content can range from 50–70% of dry weight depending on cultivation conditions. This makes Spirulina protein per 100g among the highest of any natural food source. It is a complete protein, containing all essential amino acids including phenylalanine, leucine, valine, tryptophan, threonine, lysine, isoleucine, and methionine.
Is Spirulina a complete protein?
Yes. Spirulina is considered a complete protein because it contains all the essential amino acids. The amino acid profile includes phenylalanine, leucine, valine, tryptophan, threonine, lysine, isoleucine, and methionine, along with high levels of alanine, glycine, and glutamic acid. In HIV nutrition studies, Spirulina was found to be richer in essential amino acids than soya, making it more efficient for anabolism and muscle mass reconstitution.
What nutrients does Spirulina contain besides protein?
Beyond its high protein content, dried Spirulina is a rich source of B vitamins (thiamin, riboflavin, and niacin), iron, manganese, beta-carotene, gamma-linolenic acid (GLA), calcium, magnesium, potassium, zinc, bioflavonoids, and bioactive compounds such as C-phycocyanin and sulfated polysaccharides. However, Spirulina contains predominantly pseudovitamin B12, which is biologically inactive in humans, so it should not be relied upon as a B12 source.
Does Spirulina help with anemia and iron levels?
Research suggests Spirulina may support healthy blood parameters. Multiple clinical studies, including RCTs in elderly patients, children, and adults, demonstrate improved hemoglobin levels and anemia parameters with Spirulina supplementation. A 2023 RCT confirmed significant serum iron improvements over placebo. Spirulina's iron content, B vitamins, and phycocyanin are thought to support red blood cell production.
Can Spirulina support antioxidant defense?
Human intervention studies confirm that Spirulina may improve antioxidant status, including increases in glutathione peroxidase activity, reduced urinary isoprostanes (a marker of lipid peroxidation), and improvements in total antioxidant capacity. The primary active compound, C-phycocyanin, is a potent free-radical scavenger with antioxidant and radical-scavenging properties. Research has shown these effects primarily in patient populations rather than healthy individuals.
Are there any safety concerns with Spirulina?
Spirulina has been recognized as a GRAS substance by the FDA since 2003 and is generally considered safe and well-tolerated. Common side effects may include gastrointestinal upset, fatigue, dizziness, and headache. People with phenylketonuria should avoid Spirulina due to its phenylalanine content. Spirulina should be used with caution by individuals with autoimmune conditions or who are at risk of hypoglycemia or hypotension. Quality sourcing is important, as environmental contamination with heavy metals or cyanotoxins can affect some Spirulina products.
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