Spirulina extract put to the test against long COVID inflammation
NCT ID NCT05524532
First seen Jul 30, 2026 · Last updated Jul 31, 2026 · Updated 1 time
Summary
This Phase 3 trial tests whether Immulina, a dietary supplement made from Spirulina, can lower inflammatory markers in the blood of people with long COVID (PASC). About 100 adults aged 18 to 99 will take either Immulina or a placebo for 12 weeks. Researchers will measure changes in inflammation-related chemicals like IL-6, CRP, and D-dimer, as well as symptoms such as fatigue and sleep quality.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- a highly standardized extract of Spirulina called Immulina
- What this could lead to
- If it works, this could point toward a natural supplement to ease long COVID symptoms by lowering inflammation.
- What could go wrong
- This is a relatively small trial, and dietary supplements often show mixed results. The effect may be modest or no better than placebo.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 3
Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.
- Participants
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101 people
The number who actually took part.
- Started
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Jul 2023
- Finished
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Jul 2025
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 to 99 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Males and females, 18 to 99 years old * If female of child bearing potential, using acceptable means of birth control or postmenopausal for at least two years * Body temperature between 36.1°C and 37.7°C. * Has completed the 4-week washout period (if applicable), i.e., has refrained from using internally-consumed dietary supplements prior to Study Day 1 and through the completion of the study * A minimum of 2 hours fasting (except water) prior to all of the blood draws * Willing and able (in the opinion of study staff) to comply with all study requirements, including swallowing size 4 capsules (approximately 0.5" long and 0.25" diameter) and having phlebotomy * Good written and verbal English skills; able to follow instructions (in the investigator's opinion) * Not participating in a clinical study, currently or within the last 30 days * Signed informed consent Exclusion Criteria: * Pregnant or lactating * Digestive tract disorders or conditions, such as (but are not limited to): ulcers, ulcerative colitis, Crohn's disease, gastric bypass, colostomy, ischemic colitis, gastroesophageal reflux disease (GERD), irritable bowel disease (IBD), diverticulitis that would be expected to impact on the oral disposition of the Immulina dietary supplement * Existence of any surgical and/or medical condition, significant disease or disorder, or any finding that may, in the judgment of the investigator, put the volunteer at risk or compromise study participation. * Any blood-thinning or clotting concomitant medication (prescription anticoagulants) * Donation or loss of 400 mL or more of blood within 8 weeks of Study Day 1 or unwilling to abstain from donation of blood during the study * Known or suspected allergy or sensitivity to Immulina, cellulose * History of drug or alcohol abuse within the last 12 months
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Louisiana State University
New Orleans, Louisiana, 70112, United States
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MaineHealth
Portland, Maine, 04101, United States
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Pennington Biomedical Research Center
Baton Rouge, Louisiana, 70808, United States
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University of Hawaii
Honolulu, Hawaii, 96813, United States
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University of Mississippi Medical Center
Jackson, Mississippi, 39216, United States
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University of Nebraska Medical Center
Omaha, Nebraska, 68198, United States
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University of Oklahoma
Oklahoma City, Oklahoma, 73104, United States
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University of Puerto Rico
San Juan, Puerto Rico, 00935, Puerto Rico
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West Virginia University
Morgantown, Virginia, 26506, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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- Five years on: how does long COVID evolve?
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- Brain training program aims to restore cognitive function in veterans with long COVID