IngredientsArthrospira is a genus of multicellular, filamentous, and photosynthetic cyanobacterium with a helical or spiral shape. Arthrospira platensis, one of the most cultivated species, is commonly referred to as "Spirulina." The common name "spirulina" derives from the Latin word for "small spiral," reflecting the organism's characteristic coiled morphology. Spirulina was initially classified under the plant kingdom due to its rich plant pigments and its ability to photosynthesize, but was later placed into the bacterial kingdom (cyanobacteria) due to its genetic, physiological, and biochemical makeup.
The taxonomy of commercially relevant spirulina has undergone significant revision. In 2019 it was found that the cultivated species differ too much from the type species of Arthrospira to be in the genus, necessitating a renaming to Limnospira to reflect biological reality. A scientific distinction therefore exists between spirulina and the genus Arthrospira. The current formally accepted scientific name for the primary commercially cultivated species is Limnospira platensis (formerly Arthrospira platensis; formerly Spirulina platensis). The term "spirulina" (without italicizing and usually without capitalization) remains in use for historical reasons.
Species of Arthrospira have been isolated from alkaline brackish and saline waters in tropical and subtropical regions. Among the various species included in the genus, A. platensis is the most widely distributed and is mainly found in Africa, but also in Asia. Another commercially significant species is Arthrospira maxima (also reclassified under Limnospira), which was originally harvested from Lake Texcoco in Mexico.
Once harvested, the spirulina biomass is dried and then usually powdered or compressed into tablets or bricks. It is then sold either by itself as a dietary supplement or added to various foods for consumption by humans or animals. Common examples of foods containing spirulina are cereal bars, biscuits and crackers, spreads, soups, and pasta.
Spirulina is usually dosed in the range of 2 to 10 grams daily in whole powder or capsule form. Extracts are sometimes used, but they are less thoroughly studied and do not contain the full array of compounds found in dried spirulina. Spirulina (Arthrospira platensis) has been recognized as a GRAS (Generally Recognized as Safe) substance since 2003 (FDA, GRN 000127) and is currently consumed in the US as a dietary supplement.
Spirulina was a food source for the Aztecs and other Mesoamericans until the 16th century; the harvest from Lake Texcoco in Mexico and subsequent sale as cakes were described by one of Cortés' soldiers. In Mexico circa 1300 AD, the Aztecs harvested Arthrospira from Lake Texcoco and used it to make a sort of dry cake called tecuitlatl.
Aztecs skimmed spirulina from lakes in the Valley of Mexico, including Lake Texcoco, with nets or shovels. Once harvested, the Aztecs sun-dried the algae and cut it into bricks. When preserved this way, it would remain edible for a year. The Aztecs called the algae tecuitlatl and ate it with tortillas or toasted corn. Sometimes it was combined with chiles and tomatoes to make a sauce. Spirulina was found in abundance at Lake Texcoco by French researchers in the 1960s, but no reference to its use by the Aztecs as a daily food source was made after the 16th century, probably because of the draining of the surrounding lakes for agriculture and urban development.
Very likely the use of spirulina as food in Chad dates back to the same period, or even earlier, to the Kanem Empire (ninth century AD). The topic of tecuitlatl, which was discovered in 1520, was not mentioned again until 1940, when the Belgian phycologist Pierre Dangeard mentioned a cake called dihe consumed by the Kanembu people, who harvest it from Lake Chad in the African nation of Chad. In Chad, spirulina is still harvested and processed by hand into cakes known locally as "dihe" for use in a sauce for meat and fish. It is an important part of their local economy, allowing the women of the village who harvest and process the dihe a certain amount of independence.
At the beginning of the 1970s, the IFP (French Petroleum Institute) asked the company SOSA-TEXCOCO for permission to study this blue-green algae. Dr. Clément was particularly interested in the many nutritional benefits of spirulina, including its high protein content. This protein research drew the attention of the scientific world to this microalga. Studies on spirulina showed that it could become a potential food source and attracted growing interest, marking the beginning of large-scale production in the late 1970s.
Dried spirulina is 5% water, 24% carbohydrates, 8% fat, and 57% protein. In a reference amount of 100 g, dried spirulina powder supplies 290 kilocalories and is a rich source (20% or more of the Daily Value) of numerous essential nutrients, particularly B vitamins (thiamin, riboflavin, and niacin), and dietary minerals, such as iron and manganese. The most abundant component of spirulina is protein, which accounts for 50–70% of its dry weight.
Spirulina has a high, if somewhat variable, protein content (normally within the range of 57–70% of dry weight), beneficial fatty acids such as γ-linolenic and palmitic acid, vitamins and vitamin precursors (notably B12 analogues, astaxanthin, zeaxanthin, and β-carotene), and minerals (particularly iron, potassium, calcium, zinc, and selenium).
The lipid content of spirulina is about 8% by weight. The polyunsaturated fatty acids include gamma-linolenic acid and linoleic acid. In contrast to the "high" content reported in a 2003 study, two other analyses found low levels of omega-3 fatty acids in spirulina.
Spirulina constitutes about 50–70% protein content and is rich in essential amino acids, including phenylalanine, leucine, valine, tryptophan, threonine, lysine, isoleucine, and methionine. The amino acid profile shows high levels of alanine, glycine, and glutamic acid per 100 g of protein.
Phycocyanin (PC) is a light-harvesting, pigment-binding protein isolated from algae. Phycobiliproteins are the major fluorescent proteins present in spirulina that are responsible for light uptake. They are subdivided into phycoerythrin (PE), phycocyanin (PC), and allophycocyanin (APC), according to their pigment colors. Among the abundant bioactive compounds belonging to spirulina, phycocyanin stands out as a characteristic pigment-protein complex that confers significant health benefits.
Certain constituents such as polysaccharides (Rhamnose and Glycogen) and the essential fat GLA are absorbed easily by human cells and help in energy release. The active component of the water extract of S. platensis is a sulfated polysaccharide, calcium spirulan (Ca-Sp). Spirulina also contains glycolipids, sulfolipids, and phycobilins (phycocyanin, allophycocyanin, and phycoerythrin).
Spirulina contains no vitamin B12 naturally, and spirulina supplements are not considered a reliable source of vitamin B12, as they contain predominantly pseudovitamin B12 (Coα-[α-(7-adenyl)]-Coβ-cyanocobamide), which is biologically inactive in humans.
C-phycocyanin (C-PC) is one of the major biliproteins of spirulina with antioxidant and radical scavenging properties. C-PC, a selective cyclooxygenase-2 (COX-2) inhibitor, induces apoptosis in lipopolysaccharide-stimulated RAW 264.7 macrophages. Spirulina contains antioxidant compounds like flavonoids and beta-carotene, which can greatly lower oxidant and inflammatory factors.
Spirulina has the ability to modulate immune functions and exhibits anti-inflammatory properties by inhibiting the release of histamine by mast cells. These effects are largely attributed to phycocyanin and GLA, which help regulate lipid metabolism and prevent the accumulation of fats in blood vessels.
One of the components of spirulina is noted to be glycolipid H-b2, which inhibits pancreatic lipase activity in a dose-dependent way, thus reducing postprandial triglyceride levels. Similar effects may be exerted by phycocyanin as well. In a study with spirulina platensis concentrate, it was found that SPC could bind cholesterol metabolites (bile acids) and decreased cholesterol solubility. Feeding rats with SPC significantly increased fecal excretion of cholesterol and bile acid.
The proposed mechanism of action of spirulina for weight loss includes reduction in macrophage infiltration into visceral fat, prevention of hepatic fat accumulation, reduction in oxidative stress, improvement in insulin sensitivity, and satiety. Reduction in appetite may be due to an improvement in leptin resistance in the arcuate nucleus.
Peripheral blood mononuclear cells isolated before and after spirulina feeding showed altered levels of cytokines (IL-4, IFN-γ, and IL-2), which are important in regulating IgE-mediated allergy. One study showed that high-dose spirulina significantly reduced IL-4 levels by 32%, demonstrating protective effects toward allergic rhinitis. One study demonstrated that spirulina enhances IgA production in human saliva, suggesting a role in mucosal immunity.
This is the most extensively studied area for spirulina in human clinical trials, and the area with the strongest aggregate evidence.
A meta-analysis identified 12 trials with 14 arms. The amount of spirulina ranged from 1 to 19 g/day, and intervention durations ranged from 2 to 48 weeks. Overall, data synthesis showed that spirulina supplements significantly lowered total cholesterol (WMD = −36.60 mg/dL; 95% CI: −51.87 to −21.33; P=0.0001), LDL cholesterol (WMD = −33.16 mg/dL; 95% CI: −50.52 to −15.75; P=0.0002), triglycerides (WMD = −39.20 mg/dL; 95% CI: −52.71 to −25.69; P=0.0001), VLDL cholesterol (WMD = −8.02 mg/dL; 95% CI: −8.77 to −7.26; P=0.0001), fasting blood glucose (WMD = −5.01 mg/dL; 95% CI: −9.78 to −0.24; P=0.04), and diastolic blood pressure (WMD = −7.17 mmHg; 95% CI: −8.57 to −5.78; P=0.001).
A more recent GRADE-assessed systematic review and dose-response meta-analysis corroborated these findings. Pooled results of 20 studies (23 arms and 1,076 participants) indicated that spirulina intervention significantly reduced LDL-C (SMD: −0.6), TC (SMD: −0.6), and TG (SMD: −0.6) levels while HDL-C levels were significantly increased (SMD: 0.3).
A separate meta-analysis of 23 studies (1,035 participants) found that spirulina supplementation alone significantly reduced body weight, total cholesterol, triglycerides, and LDL-C, while increasing HDL-C.
An umbrella review of meta-analyses found that spirulina supplementation consistently produces a robust, significant improvement in the atherogenic lipid profile, with strong reductions in LDL-C, triglycerides, and total cholesterol. A significant, clinically relevant reduction in systolic blood pressure was also confirmed.
One included trial demonstrated benefits of spirulina maxima in 40 hypertensive patients without cardiovascular disease when supplemented with 2 g of spirulina per day versus placebo for 3 months. In those given spirulina, there was significant reduction in BMI, weight, systolic blood pressure (149±7 mmHg vs. 143±9 mmHg, p=0.0023), and arterial stiffness index.
Evidence strength: Spirulina consumption may be considered as an adjunct to the prevention and treatment of CVD in humans. However, further large, high-quality, double-blind randomized clinical trials investigating the long-term effects and risk of spirulina supplementation on cardiovascular metabolic biomarkers and cardiovascular morbidity are needed. The review identifies a critical need for future research: longer-duration, well-powered trials with standardized spirulina preparations to translate these promising cardiometabolic signals into definitive clinical practice guidelines.
A clinical trial showed spirulina supplementation (2 g/day) for 2 months could ameliorate fasting plasma glucose, postprandial blood glucose, and HbA1c levels in patients with type 2 diabetes. Spirulina's protein and amino acid constituents may elevate blood glucose transport to peripheral tissues and stimulate insulin secretion from β-cells.
However, the overall evidence on glycemic outcomes is less consistent. The evidence for glycemic control remains inconsistent, suggesting spirulina's primary cardiometabolic benefits are mediated through lipid and blood pressure pathways rather than improved glucose metabolism. One double-blind RCT found spirulina sauce was not effective for glycemic control in type 2 diabetes; however, it could be useful for controlling appetite and ameliorating lipid profile.
Evidence strength: Preliminary and mixed. Individual positive RCTs exist, but aggregate evidence is inconsistent. More standardized trials are needed before conclusions on glycemic benefit can be drawn.
A double-blind randomized clinical trial carried out in Turkey involved 150 patients with a clinical history of allergic rhinitis. The first group received treatment with spirulina (2,000 mg/day divided into 5 tablets) for 6 months, and the second group received placebo for the same period. Spirulina consumption significantly improved the allergic symptoms compared with placebo, including nasal discharge, sneezing, nasal congestion, and itching. It was concluded that spirulina was clinically effective in managing allergic rhinitis through its anti-inflammatory and/or antioxidant properties.
The positive effects of spirulina in allergic rhinitis are based on adequate evidence but larger trials are required.
Evidence strength: Moderate. A small number of RCTs (including double-blind designs) demonstrate benefit, but sample sizes are limited and more large-scale trials are needed.
Spirulina consumption may exert beneficial effects on enhancement of the antioxidant system. A marginal significant increasing effect on total antioxidant capacity (TAC) and superoxide dismutase (SOD) activity was found with spirulina administration. However, it did not affect glutathione peroxidase (GPx) activity. One study examined the effect of spirulina supplementation on oxidative stress biomarkers, revealing that this supplement can improve certain biomarkers. In three clinical trials, spirulina supplementation improved levels of oxidative stress biomarkers in patients.
To date there are no in vivo human studies providing strong evidence supporting possible antioxidant effects of spirulina specifically in healthy individuals.
Evidence strength: Preliminary. Results across clinical trials are mixed, and findings have mainly come from patient populations rather than healthy subjects.
Spirulina supplementation increases IL-2 levels in healthy people regardless of dosage or intervention length, according to one meta-analysis. An investigation in elderly Korean participants found that spirulina supplementation may influence the expression of inflammatory markers like IL-2 and tumor necrosis factor (TNF)-α through monocyte chemotactic protein-1 (MCP-1), suggesting that spirulina is useful for improving immune function. Spirulina supplementation has been found to help increase corpuscular hemoglobin and ameliorate anemia and immunosenescence in older patients.
Evidence strength: Preliminary. Most immune-related data comes from small studies in specific populations (elderly, HIV-infected). Larger, well-controlled trials are needed.
The combined antioxidant and immune modulation characteristics of spirulina may have a possible mechanism of tumor destruction and hence play a role in cancer prevention. However, there are many animal and in vitro studies and only one trial with human subjects, which looked specifically at the effects of spirulina on oral carcinogenesis, in particular leukoplakia.
Spirulina fusiformis was studied for its ability to prevent premalignant lesions in tobacco chewers. Spirulina was given at a dose of 1 g/day for 12 months. Regression of oral leukoplakia was seen in 20 of 44 patients ingesting spirulina (45%) compared to 3 of 43 in the placebo group (7%). Within one year of discontinuing spirulina supplementation, recurrent lesions were seen in half of the initial responders.
The anticancer activity of C-phycocyanin has been largely described and molecular mechanisms investigated, but until now there has been no investigation on human subjects. Only one study described the activity for the whole spirulina, which looked specifically at oral carcinogenesis.
It is believed that the anticancer effects of spirulina are perhaps derived from β-carotene, a known antioxidant; however, the link between β-carotene level and carcinogenesis cannot be established as the etiology of carcinoma is frequently multifactorial.
Evidence strength: Very weak for anticancer effects overall in humans. The single meaningful human trial (oral leukoplakia) produced intriguing but inconclusive results. No controlled human trials exist for other cancers.
Randomized, single-blind studies showed that spirulina could improve the nutritional status of malnourished HIV patients, leading to a significant increase in CD4+ cells and a corresponding decrease in viral load. When comparing fat-free mass between two groups at the end of 12 weeks of nutritional supplementation, the fat-free mass was significantly greater in the spirulina group, suggesting that spirulina intake is more efficient in correcting loss of fat-free mass in persons infected with HIV than soya. Compared to soya, spirulina is richer in essential amino acids, important for anabolism and muscle mass reconstitution.
In a clinical trial where all participants took antiretroviral therapy, no significant variations in the CD4+ T-cell count were reported, but the group taking spirulina as an adjunct to standard therapy had better control over viral replication and improved oxidant/antioxidant balance. In general, spirulina can have antioxidant, cardio-protective, and lipid-lowering effects in patients with HIV, and it can also help them against malnutrition, since it represents a good source of proteins and micronutrients.
Evidence strength: Moderate for nutritional support in malnourished HIV patients; preliminary for immunological outcomes (CD4 counts, viral load). Evidence is inconsistent across studies.
The active component of the water extract of S. platensis is a sulfated polysaccharide, calcium spirulan (Ca-Sp). According to Hayashi et al., Ca-Sp inhibits the in vitro replication of several enveloped viruses including Herpes simplex type I, human cytomegalovirus, measles and mumps virus, influenza A virus, and HIV-1. An extract from spirulina called cyanovirin-N inhibited HIV infection of peripheral blood mononuclear cells in vitro, though the clinical implications of this finding have yet to be determined.
There are no in vivo studies providing strong evidence supporting the possible antiviral properties of spirulina.
Evidence strength: Very weak. Evidence is limited to in vitro and some animal studies. No human clinical trials have demonstrated antiviral efficacy of spirulina.
One randomized, double-blind clinical trial investigated the effect of spirulina on cardiometabolic risk factors, oxidative stress biomarkers, glycemic profile, and liver enzymes in NAFLD patients. The trial included 46 patients allocated to consume either spirulina sauce or placebo, each 20 g/day for 8 weeks. Fatty liver grade was significantly different between the two groups. A significant change for ALT and AST (liver enzymes) was seen between the two groups, while ALP serum levels were not significantly different.
Evidence strength: Preliminary. This area is supported by only a small number of clinical trials with limited sample sizes.
The current literature supports the benefits of spirulina for reducing body fat, waist circumference, body mass index, and appetite, and shows that spirulina has significant benefits for improving blood lipids. In one double-blind RCT, no significant change was observed in body composition and anthropometric measurements except waist circumference, which was reduced (MD: −2.65 cm; 95% CI: −3.91 to −1.38; P=0.001).
Evidence strength: Preliminary to moderate. Meta-analytic evidence suggests modest reductions in weight and waist circumference, but effect sizes are small and study quality is variable.
Spirulina is usually dosed in the range of 2 to 10 grams daily in whole powder or capsule form. Extracts are sometimes used, but they are less thoroughly studied and do not contain the full array of compounds found in dried spirulina.
Higher doses of spirulina, in the range of 4 to 10 grams daily, appear to be most effective for improving lipid profiles and possibly for reducing fatigue during endurance exercise. A lower dose of 2 grams daily may help reduce symptoms of allergic rhinitis.
Dosages reported across specific studies include:
A safe upper limit of 10 grams per day is commonly cited in the literature, and most studies showing benefits use doses at or below this level. A few studies have used doses up to 19 grams per day without significant adverse events, though gastrointestinal effects (nausea, loose stools) become more common above 10 grams.
Spirulina (Arthrospira platensis) has been recognized as a GRAS substance since 2003 (FDA, GRN 000127). The safety of spirulina has been established through centuries of food use and numerous toxicology studies. Spirulina doses of 10 to 19 grams per day over several months have been used safely.
Spirulina is generally considered to be safe and well-tolerated. The most commonly reported side effects include gastrointestinal upset (e.g., abdominal cramps, diarrhea, nausea, vomiting), fatigue, dizziness, headache, and skin irritation (e.g., itching, rash). Additionally, rare severe reactions such as rhabdomyolysis and anaphylaxis have been reported.
Allergy to spirulina is not commonly reported or diagnosed. However, most of the described cases regarding allergy to spirulina according to WAO Anaphylaxis Guidance 2020 were classified as anaphylaxis, ranging from mild (grade 2) to severe (grade 4) based on patient symptoms.
The safety of spirulina products may also depend on cultivation conditions and environmental contamination, as cyanobacteria are capable of adsorbing heavy metals from their surroundings. Previous studies have shown that Spirulina platensis possesses a strong sorption capacity for certain metals such as cadmium, which may influence the elemental composition of derived products. Analytical assessments have detected trace levels of lead, mercury, cadmium, and arsenic in some spirulina preparations.
Heavy-metal contamination of spirulina supplements has raised concern. The Chinese State Food and Drug Administration reported that lead, mercury, and arsenic contamination was widespread in spirulina supplements marketed in China. One study reported the presence of lead up to 5.1 ppm in a sample from a commercial supplement.
Some cyanobacteria are capable of producing microcystins, which have a number of adverse health effects, including the promotion of hepatocellular carcinoma.
Concerns exist regarding heavy metal contamination and potential drug interactions due to spirulina's effects on cytochrome P450 enzymes. Spirulina should be used with caution by people with autoimmune conditions, who are at risk of hypoglycemia or hypotension (low blood pressure), at risk of bleeding, or have impaired liver function.
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, a rare genetic disorder that prevents the body from metabolizing phenylalanine.
Spirulina supplements are not considered a reliable source of vitamin B12, as they contain predominantly pseudovitamin B12, which is biologically inactive in humans. Individuals relying on spirulina as a primary source of vitamin B12 (e.g., vegans) should be aware of this limitation and seek verified sources of active cobalamin.
Health conditions that Spirulina may help support.
Spirulina (Arthrospira platensis) modulates immune function and inhibits histamine release from mast cells. A randomized double-blind placebo-controlled 12-week trial in allergic rhinitis patients showed high-dose Spirulina significantly reduced IL-4 levels by 32%, demonstrating a protective anti-allergic immunological effect. It is one of the few dietary supplements with direct RCT evidence specifically in allergic rhinitis.
Spirulina (Arthrospira platensis) is a blue-green cyanobacterium rich in iron, B vitamins, phycocyanin, and cofactors supporting red blood cell production. Multiple clinical studies including RCTs in elderly patients, children, and adults with ulcerative colitis demonstrate improved hemoglobin and anemia parameters with supplementation.
Human intervention studies confirm spirulina improves 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 is C-phycocyanin, a potent free-radical scavenger. Spirulina's antioxidant effect is described as confirmed by intervention studies in a PubMed review covering multiple human trials.
Multiple RCTs and a systematic meta-analysis report that spirulina supplementation significantly reduces appetite scores and food intake in overweight or obese individuals. A double-blind, placebo-controlled study in 52 obese adults found that 12 weeks of spirulina supplementation significantly reduced food intake and body weight compared with placebo. The mechanism proposed involves increased GLP-1 release, which induces satiety, as well as phenylalanine-mediated cholecystokinin release.
Clinical trials in hypertensive patients show spirulina reduces endothelial damage markers including sVCAM-1, sE-selectin, and endothelin-1, alongside improvements in systolic blood pressure. A prospective randomized pilot study found 4.5 g/day of Spirulina maxima for 12 weeks produced statistically significant reductions in these vascular injury biomarkers in hypertensive patients. Preliminary evidence also suggests benefits in arterial stiffness in older adults with early vascular dysfunction.
A 2022 systematic review of 13 controlled trials found spirulina demonstrates ergogenic potential during submaximal exercise, increasing oxygen uptake and improving exercise tolerance. Spirulina's antioxidant content is hypothesized to reduce exercise-induced oxidative stress, with some studies showing increased fat oxidation during exercise. Evidence quality is modest; effects appear more consistent in athletes with suboptimal antioxidant dietary intake.
A meta-analysis of 5 RCTs (n=230) found spirulina supplementation significantly lowered systolic BP (MD: −4.59 mmHg) and diastolic BP (MD: −7.02 mmHg), particularly in hypertensive patients. Additional trial data shows 8 g spirulina acutely decreased systolic BP by 4% in healthy young adults. Proposed mechanisms include ACE-inhibitory tripeptides, nitric oxide pathway modulation, and phycocyanin-mediated reduction of oxidative stress in the vasculature.
A meta-analysis of 8 RCTs in type 2 diabetes patients found spirulina supplementation produced a significant reduction in fasting blood glucose (−17.88 mg/dL, 95% CI: −26.99, −8.78). Clinical trials also show reductions in post-prandial blood glucose and insulin sensitivity improvements, though effects on HbA1c are inconsistent. Proposed mechanisms include inhibition of alpha-glucosidase and alpha-amylase, as well as AMPK-mediated GLUT4 upregulation in skeletal muscle.
A meta-analysis of 7 RCTs found spirulina supplementation significantly reduced total cholesterol (MD: −11.83 mg/dL) and triglycerides (MD: −15.34 mg/dL) in adults with obesity, diabetes, or dyslipidemia. Human studies also consistently report increases in HDL-cholesterol. Proposed mechanisms include HMG-CoA reductase inhibition, decreased intestinal cholesterol absorption, and phycocyanin-mediated decreases in serum total cholesterol and atherogenic index.
Spirulina (Arthrospira platensis/maxima) is a nutrient-dense cyanobacterium rich in protein, B vitamins, iron, and phycocyanins. Clinical studies demonstrate Spirulina reduces exercise-induced fatigue, improves aerobic capacity, and increases time to exhaustion. An RCT showed improved muscle strength and reduced fatigue in older adults.
Spirulina has human clinical and meta-analytic evidence supporting a moderate anti-inflammatory effect, primarily demonstrated through reductions in CRP, IL-6, and TNF-α. Its key bioactive compound, C-phycocyanin, inhibits COX-2 and suppresses NF-κB signaling, two central pathways in chronic inflammation. A 2025 systematic review and meta-analysis of 22 RCTs (5,385 participants) found significant reductions in CRP (SMD: −0.972), IL-6 (SMD: −0.532), and TNF-α (SMD: −0.579). Evidence is promising but tempered by heterogeneity across trials and variability in study quality.
A 2021 scoping review (PMC) of experimental and clinical evidence found preliminary clinical studies suggest spirulina can reduce mental fatigue, protect brain vessel endothelium from damage, and regulate internal pressure, potentially contributing to cerebrovascular health. Use of spirulina in malnourished children has been shown to ameliorate motor, language, and cognitive skills. Robust human RCT data specifically targeting cognitive decline in aging adults are limited; preclinical and mechanistic evidence is more extensive.
Spirulina is a cyanobacterium rich in protein, B vitamins (including B12 equivalent), iron, and phycocyanin, providing multiple substrates for energy metabolism. RCTs in athletes show spirulina supplementation improves exercise performance, delays fatigue onset, and reduces post-exercise oxidative stress. It is used traditionally in Africa and Mexico as an energy-rich food.
Spirulina (Arthrospira platensis) is a blue-green algae with chelating activity and antioxidant compounds (phycocyanin, beta-carotene) that protect against heavy metal-induced oxidative damage. A clinical study found spirulina plus zinc reduced urinary arsenic levels and improved skin manifestations in arsenic-contaminated children. 58 preclinical studies and 5 clinical studies support its use against arsenic, cadmium, lead, and mercury toxicity.
Spirulina (Arthrospira platensis) has demonstrated anti-allergic effects in multiple clinical trials, including a double-blind RCT showing it significantly reduced IL-4 levels by 32% in allergic rhinitis patients. A clinical trial of 65 patients found 2g/day of spirulina outperformed cetirizine (10mg) in reducing nasal symptoms. Its C-phycocyanin content drives immunomodulation of IgE-mediated allergy responses.
Spirulina protein hydrolysates have demonstrated potent DPP-IV inhibition (up to 74%) in a 2023 food science study, thereby preserving endogenous GLP-1. Its blue pigment phycocyanin has independently shown DPP-IV inhibitory activity, supporting GLP-1-mediated satiety.
Spirulina (Arthrospira platensis) is a blue-green microalgae used as a nutritional supplement with documented gut microbiota-modulating effects, including promotion of Lactobacillus and inhibition of pathogenic bacteria. Several preclinical and early human studies support its prebiotic-like activity and gut microbiome modulation.
Spirulina is a cyanobacterium containing C-phycocyanin, beta-carotene, gamma-linolenic acid, and phytoestrogens with documented antioxidant and anti-inflammatory effects relevant to aging. Multiple RCTs in older adults demonstrate spirulina supplementation reduces oxidative stress markers, improves anemia, and enhances immune function relevant to healthy aging.
A systematic review and meta-analysis of 5 RCTs found spirulina supplementation produced a significant mean reduction in body weight of 1.56 kg (95% CI: −1.98 to −1.14) in obese subjects. Effects on BMI and waist circumference are also reported across multiple trials. A 2025 GRADE-assessed meta-analysis confirmed spirulina reduces appetite, improves insulin sensitivity, and exerts anti-inflammatory effects relevant to obesity management.
Multiple RCTs and meta-analyses demonstrate spirulina reduces triglycerides, total cholesterol, and LDL while raising HDL, and lowers blood pressure in hypertensive patients — key cardiovascular risk factors. A 2025 systematic meta-analysis of RCTs confirmed consistent positive clinical outcomes for cardiovascular risk reduction. Phycocyanin reduces oxidative damage to endothelial cells and protects against doxorubicin-induced cardiotoxicity in preclinical models.
Spirulina (Spirulina platensis) is a blue-green cyanobacterium microalga studied for chelating activity and antioxidant/protective effects against heavy metals including cadmium, mercury, lead, and arsenic. In vitro and animal studies demonstrate it reduces metal toxicity and supports antioxidant enzyme activity. It is included alongside chlorella in most natural heavy metal detox protocols.
A double-blind placebo-controlled RCT in 50 obese hypertensive patients found spirulina (2 g/day, 3 months) improved insulin sensitivity as assessed by euglycemic clamp, alongside lipid and antioxidant improvements. A 2025 systematic review confirmed spirulina enhances glycemic control and insulin sensitivity by increasing insulin production and reducing inflammatory mediators. AMPK activation and GLUT4-mediated glucose uptake are proposed mechanistic pathways.
Spirulina (Arthrospira platensis) is a blue-green microalga with high non-heme iron content. Clinical trials show it improves hematological parameters including hemoglobin and serum iron in anemic individuals, and a 2023 RCT confirmed significant serum iron improvements over placebo.
Spirulina, a blue-green algae rich in phycocyanin and chlorophyll, demonstrates hepatoprotective effects in preclinical models and emerging clinical trials, reducing liver enzyme markers and oxidative stress. A 2025 PMC review confirmed spirulina's capacity to reduce liver damage biomarkers and facilitate heavy metal elimination from the body. A 2024 comprehensive clinical trials review confirmed spirulina reduced liver enzymes in clinical studies.
A systematic review of 13 human clinical studies confirmed spirulina supplementation has a positive effect on metabolic syndrome, improving blood pressure, blood sugar, lipid profiles, and body weight simultaneously. An RCT in 40 metabolic syndrome subjects found a spirulina liquid extract decreased urinary isoprostanes and plasma triglycerides while increasing HDL-cholesterol. The active bioactives phycocyanin, Ile-Gln-Pro, gamma-linolenic acid, and glycolipid H-b2 are identified as mechanistic drivers.
Spirulina has demonstrated effects across multiple metabolic parameters in human trials, including reductions in body weight, fasting glucose, triglycerides, and total cholesterol, alongside improvements in insulin sensitivity and antioxidant status. A systematic review identified 13 human clinical studies documenting broad metabolic improvements across dosages from 20 mg to 6 g over 17–360 days. The active compounds phycocyanin, gamma-linolenic acid, and glycolipid H-b2 are identified as key mediators.
Phycocyanin, the primary bioactive in spirulina, has been shown to preserve mitochondrial function and protect against mitochondrial damage from reactive oxygen species. Preclinical evidence indicates spirulina's C-phycocyanin protects pancreatic beta-cell mitochondria by scavenging ROS, and spirulina normalizes mitochondrial antioxidant enzyme activities (SOD, CAT, GPx). A study in equine metabolic syndrome showed Spirulina platensis improved mitochondrial function in cells impaired by elevated oxidative stress.
Spirulina has been investigated for its ability to reduce exercise-induced muscle damage markers and oxidative stress, with a study in elite rugby players finding it potentially prevents lipid peroxidation and skeletal muscle damage during a season of intense training. Results across trials are mixed: some show reductions in CK and MDA after exhaustive exercise, while others show no significant differences in DOMS or performance markers. The 2022 systematic review concludes evidence remains scarce in healthy subjects.
Spirulina is a blue-green microalgae rich in protein, phycocyanin, and antioxidants that has been studied in multiple RCTs for endurance performance. Clinical trials show it reduces exercise-induced oxidative stress, decreases fatigue, improves time to exhaustion, and supports VO2max. It also contains iron, B vitamins, and beta-carotene that contribute to oxygen-carrying capacity.
Spirulina was a component of the PMSoff combination supplement that demonstrated significant PMS symptom reduction in a 2025 double-blind RCT. Spirulina has documented anti-inflammatory and antioxidant properties proposed to alleviate PMS-related symptoms. It is a nutrient-dense blue-green algae used in women's reproductive health contexts.
A nutrient-dense blue-green alga with documented immunomodulatory properties, Spirulina contains phycocyanin, vitamins, minerals, and essential amino acids that support immune function and physical recovery. Clinical studies show Spirulina supplementation increases NK cell activity and reduces fatigue in various populations during recovery.
A double-blind placebo-controlled RCT (Cingi et al., Eur Arch Otorhinolaryngol, 2008; PubMed 18343939) found spirulina significantly improved nasal discharge, sneezing, nasal congestion, and itching versus placebo in allergic rhinitis patients. NCCIH lists spirulina among studied nutritional approaches for allergic rhinitis.
Spirulina, a blue-green alga, was studied in a double-blind, placebo-controlled clinical trial (Eur Arch Oto-Rhino-Laryngol, 2008) for allergic rhinitis, showing significant improvements in nasal discharge, sneezing, congestion, and itching. Its active pigment C-phycocyanin inhibits histamine release from mast cells and selectively inhibits COX-2. A comparative trial also found it comparable to cetirizine.
Spirulina (Arthrospira maxima/platensis) has been shown in multiple meta-analyses of RCTs to significantly reduce plasma triglycerides. A 2015 meta-analysis of 7 RCTs found a TG reduction of −44.2 mg/dL, and a 2023 GRADE-assessed meta-analysis of 23 studies (n=1,035) confirmed significant TG reduction (Hedge's g = −0.64).
Spirulina (Arthrospira platensis) is a blue-green algae with demonstrated immunomodulatory and antiviral properties. Its polysaccharide component calcium spirulan has shown direct antiviral activity. Clinical studies indicate spirulina supplementation modulates NK cell activity and cytokine production relevant to viral defense.
Spirulina is a blue-green alga rich in phycocyanin, chlorophyll, and antioxidants with documented hepatoprotective and heavy metal chelating properties. A 2025 PMC review found spirulina reduces oxidative stress, liver enzyme markers, and facilitates binding and excretion of heavy metals including lead, mercury, and cadmium.
Spirulina (blue-green microalgae) has been mentioned in integrative post-viral recovery literature as a binder and nutritional support supplement. An integrative medicine review (Liebertpub, 2025) cites spirulina among potential adjuncts in long COVID recovery, referencing its antioxidant, anti-inflammatory, and immune-modulating phycocyanin content. Traditional use as an immune and energy tonic is well-documented.
Body systems that Spirulina may help support.
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