Key findings from detailed records
Meta-analyses suggest modest improvements in some cardiovascular risk markers, with variation between studies. Small exercise studies do not consistently show better performance.
KNOWLEDGE RECORD
- Category
- Metabolism and cellular function
- Last Reviewed
- 2026-09-27
Names and related search termsArthrospira; Limnospira; spirulina biomass; blue-green algae
OUTCOME-SPECIFIC EVIDENCE
Scientific Evidence Profile
Assessment pending
An outcome-specific assessment has not yet been completed. This is not a finding that the ingredient is ineffective. The study records below remain available.
This profile concerns the stated outcome and population, not the ingredient as a whole. It is not a probability of benefit, a safety rating, a product efficacy rating or an indication of product adoption.
How we assess evidenceIngredient Profile
- What material is being studied?
- Spirulina powders can contain Arthrospira biomass. Carotenoids, chlorophyll and C-phycocyanin contribute to their pigment profile; powders are complex materials, not a single blue molecule. [1]
Sources for this profile
Compound properties and formulation properties are different. These sources do not establish the efficacy of a finished supplement.
- Two Classes of Pigments, Carotenoids and C-Phycocyanin, in Spirulina Powder and Their Antioxidant Activities. Identity and preparation checked against the study abstract. Funding details are not verified for this profile source. Conflict-of-interest details are not verified here.
Profile sources checked:
Read the evidence in context
- Evidence: what was measured in the stated population or experimental model.
- Inference: an interpretation connecting findings; its applicability depends on the study conditions.
- Hypothesis: a proposed explanation or effect that remains to be tested.
Why It Matters #
Spirulina usually refers to cultivated cyanobacterial biomass sold as Arthrospira or Limnospira preparations. It contains protein, pigments and micronutrients, but a few grams of powder provide a very different nutritional contribution from a protein-rich meal. Composition and the actual serving size matter more than a percentage-protein headline.
What Was Studied #
Human studies examine blood pressure, lipids and glucose, often in people with excess weight or cardiometabolic risk. Exercise trials use healthy active volunteers. A recent synthesis included 23 studies and 1,035 overweight or obese participants; these are not 23 longevity trials.[1]
Preparations range from whole biomass to enriched products and spirulina-containing foods. The map retains these distinctions: an acute beverage experiment and a silicon-enriched preparation are not interchangeable with ordinary daily powder.[5][7]
What Was Found #
An updated randomized-trial meta-analysis estimated systolic blood pressure about 4.4 mmHg lower and diastolic pressure about 2.8 mmHg lower than control. Heterogeneity was substantial, and the authors rated certainty moderate. These are pooled averages, not an expected response for every user.[2]
In 17 recreational cyclists, 6 g/day for 14 days increased measured hemoglobin concentration but did not improve the tested exercise-performance outcomes. This illustrates why a plausible marker should be checked against function.[6]
What the Evidence Means #
Risk-marker changes can be useful without proving fewer cardiovascular events. Most trials are too small or short to answer the latter question. Differences in baseline blood pressure, diet, preparation and duration complicate a single optimal-dose claim.
What We Can Learn #
Quality is part of interpreting a biomass product. Identity and testing for contaminants matter. FDA guidance on microcystins focuses particularly on contamination in blue-green-algae products such as wild-harvested AFA; AFA and cultivated spirulina are not the same organism. A warning about one product category is not evidence that every spirulina batch is contaminated.[11]
The useful comparison is the exact tested preparation, dose and outcome—not spirulina versus all food, or a change in hemoglobin versus faster cycling.
What Remains Unknown #
Independent replication using defined biomass, longer cardiovascular follow-up and consistent adverse-event reporting would clarify the value of routine supplementation. It is also unclear how much of a response depends on baseline nutritional status rather than a distinctive effect of spirulina.
LITERATURE MAP / 10 PAPERS
Compare papers by conditions and findings.
Compare populations, preparations, doses and outcomes. Detailed records below assess selected studies; the remaining entries provide a bibliographic route into related questions.
Selected: 2026-09-27. Bibliographic information checked against Europe PMC / PubMed. This editorial selection includes major trials, evidence syntheses and different research questions; it is not an exhaustive systematic review. Paper counts are not counts of independent trials.
10 RECORDS
A dash marks fields not assessed in a bibliographic-only record.
No papers match. Change the search conditions.
Explore the research Study Records
Listed doses describe study conditions, not recommended intake.
The Effect of Spirulina Supplementation on Blood Pressure in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Clinical Trials.
PubMed 39529406 DOI: 10.1002/ptr.8377
- Authors
- Shiri H, Yasbolaghi Sharahi J, Alizadeh Sani M, Mousavi SMJ, Nematollahi MH, Soleimani AA, Amri J, Panahi G.
- Journal
- Phytotherapy research : PTR
- Publication year
- 2025
- Study design
- Systematic review and meta-analysis of randomized trials
- Participants
- Adults; hypertension and overweight subgroups examined
- Dose and intervention
- Spirulina versus placebo/control; doses varied across trials
- Duration
- Search through April 2024; trial durations varied
- Outcomes and their role in the study
- Systolic and diastolic blood pressure
- Findings
- Systolic difference −4.41 mmHg (95% CI −6.74 to −2.07); diastolic −2.84 mmHg (−4.65 to −1.03).
- Limitations
- Heterogeneity about 66% and 62%; few studies for dose-response analysis. Authors rated evidence moderate certainty.
- Funding
- Not verified in the source material available for this record.
- Conflict of Interest
- Not verified in the source material available for this record.
- What We Can Learn
- A pooled risk-marker signal is present, but a precise optimal dose and event reduction are not established.
- Scope of source review
- Original abstract and bibliographic record reviewed; unavailable full-text details are not inferred.
Fourteen-Days Spirulina Supplementation Increases Hemoglobin, but Does Not Provide Ergogenic Benefit in Recreationally Active Cyclists: A Double-Blinded Randomized Crossover Trial.
PubMed 37807529 DOI: 10.1080/19390211.2023.2263564
- Authors
- Ali Y, Aubeeluck R, Gurney T.
- Journal
- Journal of dietary supplements
- Publication year
- 2024
- Study design
- Randomized, double-blind, placebo-controlled crossover trial
- Participants
- 17 recreational cyclists: 14 men and 3 women
- Dose and intervention
- 6 g/day spirulina versus placebo
- Duration
- 14 days per intervention; 14-day washout
- Outcomes and their role in the study
- Hemoglobin; submaximal exercise, maximal oxygen uptake and fatigue/performance measures
- Findings
- Hemoglobin was 150.4 versus 145.6 g/L (P=0.047), while exercise performance did not improve.
- Limitations
- Small, short crossover trial in active volunteers; concentration changes do not directly measure total red-cell mass.
- Funding
- Not verified in the source material available for this record.
- Conflict of Interest
- Not verified in the source material available for this record.
- What We Can Learn
- A blood marker changed without a demonstrated performance benefit.
- Scope of source review
- Original abstract and bibliographic record reviewed; unavailable full-text details are not inferred.
Short-Term Effects of Spirulina Consumption on Glycemic Responses and Blood Pressure in Healthy Young Adults: Results from Two Randomized Clinical Trials.
PubMed 36557218 DOI: 10.3390/metabo12121180
- Authors
- Lympaki F, Giannoglou M, Magriplis E, Bothou DL, Andreou V, Dimitriadis GD, Markou G, Zampelas A, Theodorou G, Katsaros G, Papakonstantinou E.
- Journal
- Metabolites
- Publication year
- 2022
- Study design
- Two acute randomized crossover food experiments
- Participants
- 13 healthy adults in each experiment
- Dose and intervention
- Spirulina-containing cookies (2.5 g per 50 g available carbohydrate) or beverages containing 4, 6 or 8 g
- Duration
- Single-meal testing
- Outcomes and their role in the study
- Postprandial glucose and blood pressure
- Findings
- Cookie glycemic index was similar to control (59 versus 60). Some late postprandial outcomes favored the 8 g beverage.
- Limitations
- Small acute experiments, several doses/timepoints; results do not establish sustained glycemic control.
- Funding
- Co-funded by the European Regional Development Fund and Greek national funds under project T2EDK-02975.
- Conflict of Interest
- The authors declared no conflicts and reported no funder role in design, data handling, writing or publication decisions.
- What We Can Learn
- Food matrix and timing can change the question a spirulina trial answers.
- Scope of source review
- Original full text and bibliographic record reviewed.
Cite this page
LÍFSVARÐA. Spirulina: What do cardiometabolic and exercise trials actually show? Version 1.0 / Updated 2026-10-24
https://lifsvarda.com/knowledge/spirulina/Edited by LÍFSVARÐA (product brand). Editorial policy
Primary Sources and updates
- Fu Z, Zhou S, Gu X. (2025). 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 DOI: 10.3389/fnut.2025.1624982Bibliographic record; not a detailed study appraisal.
- Shiri H, Yasbolaghi Sharahi J, Alizadeh Sani M, Mousavi SMJ, Nematollahi MH, Soleimani AA, Amri J, Panahi G. (2025). The Effect of Spirulina Supplementation on Blood Pressure in Adults: A GRADE-Assessed Systematic Review and Meta-Analysis of Randomized Clinical Trials. Phytotherapy research : PTR DOI: 10.1002/ptr.8377Original abstract and bibliographic record reviewed; unavailable full-text details are not inferred.
- Rahnama I, Arabi SM, Chambari M, Bahrami LS, Hadi V, Mirghazanfari SM, Rizzo M, Hadi S, Sahebkar A. (2023). 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 DOI: 10.1016/j.phrs.2023.106802Bibliographic record; not a detailed study appraisal.
- Machowiec P, Ręka G, Maksymowicz M, Piecewicz-Szczęsna H, Smoleń A. (2021). Effect of Spirulina Supplementation on Systolic and Diastolic Blood Pressure: Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients DOI: 10.3390/nu13093054Bibliographic record; not a detailed study appraisal.
- Lympaki F, Giannoglou M, Magriplis E, Bothou DL, Andreou V, Dimitriadis GD, Markou G, Zampelas A, Theodorou G, Katsaros G, Papakonstantinou E. (2022). Short-Term Effects of Spirulina Consumption on Glycemic Responses and Blood Pressure in Healthy Young Adults: Results from Two Randomized Clinical Trials. Metabolites DOI: 10.3390/metabo12121180Original full text and bibliographic record reviewed.
- Ali Y, Aubeeluck R, Gurney T. (2024). Fourteen-Days Spirulina Supplementation Increases Hemoglobin, but Does Not Provide Ergogenic Benefit in Recreationally Active Cyclists: A Double-Blinded Randomized Crossover Trial. Journal of dietary supplements DOI: 10.1080/19390211.2023.2263564Original abstract and bibliographic record reviewed; unavailable full-text details are not inferred.
- Virsolvy A, Benmira AM, Allal S, Demattei C, Sutra T, Cristol JP, Jouy N, Richard S, Perez-Martin A. (2025). Benefits of Dietary Supplementation with Specific Silicon-Enriched Spirulina on Arterial Function in Healthy Elderly Individuals: A Randomized, Placebo-Controlled Trial. Nutrients DOI: 10.3390/nu17050864Bibliographic record; not a detailed study appraisal.
- Karizi SR, Armanmehr F, Azadi HG, Zahroodi HS, Ghalibaf AM, Bazzaz BSF, Abbaspour M, Boskabadi J, Eslami S, Taherzadeh Z. (2023). A randomized, double-blind placebo-controlled add-on trial to assess the efficacy, safety, and anti-atherogenic effect of spirulina platensis in patients with inadequately controlled type 2 diabetes mellitus. Phytotherapy research : PTR DOI: 10.1002/ptr.7674Bibliographic record; not a detailed study appraisal.
- Hatami E, Ghalishourani SS, Najafgholizadeh A, Pourmasoumi M, Hadi A, Clark CCT, Assaroudi M, Salehi-Sahlabadi A, Joukar F, Mansour-Ghanaei F. (2021). The effect of spirulina on type 2 diabetes: a systematic review and meta-analysis. Journal of diabetes and metabolic disorders DOI: 10.1007/s40200-021-00760-zBibliographic record; not a detailed study appraisal.
- Reis G, Augusto Dos Santos Moreira Silva E, Carla Medeiros Silva D, Thabane L, Santiago Ferreira T, Vitor Quirino Dos Santos C, Paula Figueiredo Guimaraes Almeida A, Cançado Monteiro Savassi L, Dias de Figueiredo Neto A, Lanna França Reis L, Helena de Souza Campos V, Bitarães C, Diniz Callegari E, Izabel Campos Simplicio M, Barra Ribeiro L, Oliveira R, Harari O, Forrest JI, Lat PK, Dron L, Thorlund K, Mills EJ. (2024). Effect of spirulina on risk of hospitalization among patients with COVID-19: the TOGETHER randomized trial. The American journal of clinical nutrition DOI: 10.1016/j.ajcnut.2024.06.016Bibliographic record; not a detailed study appraisal.
- US FDA. Blue-Green Algae Products and Microcystins.
First published: 2026-09-27 / Version 1.0. Sources reviewed 2026-09-27. Funding and conflicts are recorded separately; an unverified disclosure is not a declaration of no funding or no conflict.