Spirulina

Spirulina is a blue-green cyanobacterium, not a true algae despite the name on most labels. It grows as a microscopic spiral filament in warm alkaline lakes. The dried biomass is roughly 60 to 70 percent protein. It also carries phycocyanin, beta-carotene, iron and a wide mineral profile.^[1]

If you have heard about spirulina for energy, immunity or as a green superfood, this page covers what it is and what the research shows for women.

Sources of spirulina

The species sold as spirulina is Arthrospira platensis. A second species, Arthrospira maxima, also appears on labels. Both were reclassified out of the genus Spirulina decades ago. The trade name stuck.^[1]

Spirulina is grown in open ponds in tropical and subtropical climates. The pigment phycocyanin gives it the deep blue-green colour. Other compounds in the dried biomass include allophycocyanin, chlorophyll a, beta-carotene and gamma-linolenic acid.^[1]

Quality matters more for spirulina than for most supplements. Open ponds can be colonised by other cyanobacteria that produce microcystins, a class of liver toxins. Some batches also contain BMAA, a neurotoxic amino acid linked to neurodegeneration in case reports.^[1] Look for products that publish third-party testing for microcystins, BMAA and heavy metals on the certificate of analysis.^[1]

How much you need

Spirulina is a food. There is no recommended daily intake.

Doses in randomised trials sit between 1 g and 8 g per day. A 2024 GRADE-assessed meta-analysis of blood pressure trials used spirulina across this range over 2 to 12 weeks of intervention.^[3] A 2025 review of edible algae trials reported that the blood pressure benefit appeared above 3 g of whole spirulina per day.^[4] As part of a multi-ingredient greens complex in a daily food sachet, spirulina works as a whole-food source of phycocyanin, carotenoids and trace minerals rather than as a clinical dose.

The science on women's health

Lipid profile and metabolic health

The strongest evidence base for spirulina sits in cardiometabolic outcomes. A 2023 GRADE-assessed dose-response meta-analysis of 20 trials and 1,076 adults reported that spirulina supplementation significantly lowered total cholesterol, LDL cholesterol and triglycerides while raising HDL cholesterol.^[2]

A 2025 cardiometabolic meta-analysis of 23 trials in adults with overweight or obesity confirmed reductions in body weight, total cholesterol, LDL and diastolic blood pressure.^[5] Iron in spirulina is absorbed without interference from phytates because the cell envelope lacks the structures that bind iron in many plant foods.^[1] Trials in iron-deficient women are still small. Spirulina is not yet supported as a stand-alone treatment for iron deficiency.

Immune function and inflammation

Phycocyanin, the blue pigment that defines spirulina, is the most studied immune-relevant compound in the biomass. In laboratory and animal models it modulates natural killer cell activity, macrophage polarisation and cytokine signalling.^[1] Human evidence for immune endpoints is thinner than for lipids.

The human signal sits in inflammatory markers and blood pressure. A 2025 dose-response meta-analysis of 7 trials in 283 adults reported that spirulina lowered serum C-reactive protein by about 0.55 mg/L versus control. CRP is a general marker of systemic inflammation.^[6] A 2024 GRADE-assessed meta-analysis reported that spirulina lowered systolic blood pressure by 4.4 mmHg and diastolic by 2.8 mmHg. The largest effects were in adults with hypertension and in trials longer than 8 weeks.^[3] A 2025 meta-analysis of edible algae confirmed spirulina was the most effective algae for blood pressure at doses above 3 g per day for at least 12 weeks.^[4]

EU authorised health claims

Under EU law, no specific health claim is currently authorised for spirulina. Botanical claims remain on hold at EU level while the European Food Safety Authority works through its review process. That means no nōuxx Green Glow communication can attach a specific health benefit to the spirulina in the formula.

Research suggests spirulina may improve lipid profile, blood pressure and inflammatory markers in some adult populations.^[2][3][6] Most trials sit in adults with overweight, hypertension or dyslipidaemia rather than healthy women. One caveat applies to vitamin B12. Most of the B12 in spirulina is a biologically inactive analogue called pseudovitamin B12. The human body cannot use it. Spirulina is not a reliable B12 source for vegan or vegetarian diets.^[1] Until larger trials in women confirm an effect at typical supplemental doses, we do not make formal health claims for spirulina.

References

[1] Gogna S, Kaur J, Sharma K, et al. Spirulina: an edible cyanobacterium with potential therapeutic health benefits and toxicological consequences. Journal of the American Nutrition Association 2023;42(6):559-572. doi.org/10.1080/27697061.2022.2103852

[2] Rahnama I, Arabi SM, Chambari M, et al. The effect of Spirulina supplementation on lipid profile: GRADE-assessed systematic review and dose-response meta-analysis of data from randomized controlled trials. Pharmacological Research 2023;193:106802. doi.org/10.1016/j.phrs.2023.106802

[3] Shiri H, Yasbolaghi Sharahi J, Alizadeh Sani M, et al. The effect of Spirulina supplementation on blood pressure in adults: a GRADE-assessed systematic review and meta-analysis of randomized clinical trials. Phytotherapy Research 2025;39(1):397-412. doi.org/10.1002/ptr.8377

[4] Casas-Agustench P, Mínguez S, Brookes Z, Bescos R. Edible algae reduce blood pressure in humans: a systematic review and meta-analysis of randomised controlled trials. Journal of Human Nutrition and Dietetics 2025;38(4):e70095. doi.org/10.1111/jhn.70095

[5] Fu Z, Zhou S, Gu X. Effects of spirulina supplementation alone or with exercise on cardiometabolic health in overweight and obese adults: a systematic review and meta-analysis. Frontiers in Nutrition 2025;12:1624982. doi.org/10.3389/fnut.2025.1624982

[6] Shahraki Jazinaki M, Rashidmayvan M, Rahbarinejad P, et al. Effects of Spirulina supplementation on C-reactive protein (CRP): a systematic review and dose-response meta-analysis. Food Science & Nutrition 2025;13(5):e70196. doi.org/10.1002/fsn3.70196