The purpose of this study is to see if some people with postural tachycardia syndrome (POTS) have higher levels of immune proteins (autoantibodies) directed against receptors of the autonomic nervous system, and if these autoantibodies make a difference in their POTS symptoms. The investigators also want to see if the levels of these autoantibodies stay the same over time.
View on ClinicalTrials.gov ↗Last updated 07 October 2026 from ClinicalTrials.gov. Trial statuses are refreshed automatically; check the registry record for the latest status and contact details.
2 trials1 open to enrolment1 completed
All interventional trials in our ClinicalTrials.gov extract that list Phenylephrine as an intervention, across Unspecified / Overlap (2). 1 is currently open to enrolment and 1 has completed.
Intervention names are normalised from the registry's own arm labels, so the same compound can appear under a brand name, a generic name or a combination; check the full agent index for related entries.
⚠️
Not medical advice. This page is an automatically compiled index of entries on ClinicalTrials.gov. Listing here is not an endorsement of any trial, sponsor or treatment, and trial status can change between our refreshes. Always confirm details on ClinicalTrials.gov and discuss participation with your own clinician.
Enrolling by invitation (1)
Completed (1)
Vasovagal Syncope (simple postural faint) is the most common cause of acute loss of consciousness. Postural tachycardia syndrome(POTS) is the most common chronic form of postural lightheadedness. Together they afflict many Americans, mostly young women, who are prevented from gainful employ or school attendance.
View on ClinicalTrials.gov ↗Frequently asked questions
How do I join a clinical trial?
Open the trial's ClinicalTrials.gov record (the "View on ClinicalTrials.gov" button), read the Eligibility Criteria and Contacts and Locations sections, and contact the study team listed there. Trials only enrol at the sites shown in the record, so check whether a site is near you or whether the study is remote/decentralised. Your own clinician can help you judge whether a trial is a sensible option and may need to provide medical records.
What do the trial phases mean?
Early Phase 1 / Phase 1 studies test safety and dosing in a small group. Phase 2 studies look for a signal of benefit in a larger group and keep checking safety. Phase 3 studies are large confirmatory trials designed to show whether a treatment works well enough for approval. Phase 4 studies follow approved treatments after they reach the market. "Phase not applicable" is used by the registry for behavioural, device, rehabilitation and other non-drug interventions.
Does the Open Source Medicine Foundation run these trials?
No. OSMF does not sponsor, run or recruit for any trial on this page. We compile public registry entries from ClinicalTrials.gov so patients and clinicians can find them in one place. For questions about a specific study, contact the sponsor or study team listed on its ClinicalTrials.gov record.
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Open Source Medicine Foundation. Phenylephrine clinical trials for Long COVID, ME/CFS and post-viral illness (2 trials, updated October 2026). Research Tracker, 07 October 2026.
Underlying dataset (JSON, CC BY 4.0):
Open Source Medicine Foundation. Phenylephrine clinical trials for Long COVID, ME/CFS and post-viral illness (2 trials, updated October 2026). Research Tracker, 07 October 2026.
https://research.opensourcemed.info/trials/by-agent/phenylephrine.htmlUnderlying dataset (JSON, CC BY 4.0):
https://research.opensourcemed.info/data/clinical_trials/clinical_trials_current.json. Source records: ClinicalTrials.gov.Related: all agents · recruiting Long COVID trials · recruiting ME/CFS trials · open in trial finder.