Short answer: Human studies offer early signs that Spirulina products and certain Spirulina-derived formulations may affect inflammation-related biomarkers or symptoms. But most did not test purified C-phycocyanin (C-PC) alone. A Spirulina trial, a peptide gel, and a multi-ingredient supplement cannot establish that phycocyanin itself caused the reported effects.
That distinction matters because Spirulina contains many compounds, and products differ in source, composition, dose, and route of use. The current clinical literature is preliminary and product-specific.
What completed clinical studies report
Periodontal inflammation and oral wound healing
A 2025 randomized split-mouth trial in 20 people with periodontitis tested a gel made from Spirulina-derived bioactive peptides after periodontal flap surgery. Compared with placebo gel, the peptide gel group had lower plaque and bleeding indices at weeks 4 and 8, and less gingival redness and pain, as well as lower analgesic use, at week 1. The intervention was a Spirulina peptide preparation, not isolated C-PC. Read the periodontal surgery trial.
Earlier small studies also applied Spirulina locally as an adjunct to scaling and root planing. One randomized study of 60 people reported greater improvements in periodontal indices and salivary malondialdehyde (MDA), an oxidative-stress marker, with Spirulina microspheres over 90 days. Another small placebo-controlled trial tested Spirulina gel at periodontal sites. These findings concern local dental formulations used alongside standard care; they do not establish an effect of oral phycocyanin supplements. See the 60-person study and the earlier gel trial.
Relapsing-remitting multiple sclerosis
A 2025 triple-blind randomized trial assigned 80 people with relapsing-remitting multiple sclerosis to 1 g per day of whole Spirulina or placebo for 12 weeks. The investigators reported lower serum IL-1β and IL-6 in the Spirulina group. Some physical quality-of-life domains also improved, while several other domains did not show significant differences. Sixty-four participants completed the trial. Since participants took whole Spirulina, these results cannot be assigned to C-PC alone. The trial measured cytokines; it did not demonstrate that NF-κB inhibition was the clinical mechanism. Read the randomized trial.
Chronic prostatitis/chronic pelvic pain syndrome
A registry-listed, one-group open-label study of FICOXPEA® is marked completed and lists 48 participants. The product combined Spirulina-extract phycocyanin (250 mg), palmitoylethanolamide (200 mg), and L-selenomethionine (11 mg), taken daily for 30 days. The planned assessments included symptom, pain, and quality-of-life scores at one and three months. Because there was no control group and the product contained several ingredients, any change could not be attributed to phycocyanin alone. I could not verify a public results report in the records checked. View the trial record.
Menstrual migraine
A 2026 retrospective study reviewed records for 61 women who used a combination of phycocyanin and palmitoylethanolamide around menstruation. The authors reported lower migraine severity, duration, perimenstrual migraine days, and analgesic use compared with each patient’s period without supplementation; total monthly migraine frequency did not change. The study had no randomized control group, and the product was a combination, so it cannot show which ingredient—if any—accounted for the association. Read the retrospective study.
What the broader Spirulina evidence adds
A 2025 systematic review and meta-analysis pooled 22 randomized trials involving 5,385 participants and reported reductions in CRP, IL-6, TNF-α, and MDA, alongside higher total antioxidant capacity, after Spirulina supplementation. This is useful context for the whole-ingredient research, but the trials evaluated Spirulina products rather than purified C-PC. The findings therefore do not prove that phycocyanin alone reduces inflammation. See the meta-analysis.
Trials now underway
- Immune markers in healthy adults (NCT07733362): The registry describes a recruiting, placebo-controlled trial of Spirulina Blue Protein capsules at 200 mg or 1,000 mg daily for 12 weeks. It plans to measure CD4+, CD8+, and natural-killer cells, along with cytokines including IL-2, IL-6, IFN-γ, and TNF-α. The results are not yet available. View the registry record.
- Recovery after partial hepatectomy (NCT07760038): A recruiting study plans to enroll about 30 adults with intrahepatic cholangiocarcinoma undergoing partial liver resection. The protocol compares 1.5 g per day of phycocyanin with maltodextrin for three weeks before and after surgery, and evaluates liver enzymes, inflammatory markers, liver repair, and gut-microbiota measures. View the registry record.
A C-phycocyanin mucosal adhesive paste study for recurrent aphthous stomatitis was also described in the source material, but I could not verify a public trial registration or primary study record, so it is not counted here as a confirmed ongoing trial.
How strong is the evidence?
NF-κB inhibition is a frequently proposed anti-inflammatory mechanism in laboratory and animal research. In the human studies above, however, investigators either measured selected biomarkers or tracked symptoms; the studies did not establish NF-κB suppression as the cause of a clinical benefit. The clinical evidence also combines different materials: whole Spirulina, Spirulina-derived peptides, extracts, and multi-ingredient formulas. They should not be treated as interchangeable.
Takeaway: Human research has produced preliminary signals worth following, especially in periodontal applications and biomarker studies. It has not yet established purified phycocyanin as a proven treatment for inflammation, multiple sclerosis, prostatitis, or migraine. Larger, well-controlled studies that clearly define the ingredient and formulation are needed to determine whether C-PC itself offers a reproducible clinical benefit.