(NewsNation) — The National Institute of Health has begun two phase 2 clinical trials to test the “safety and effectiveness” of three possible long COVID treatments for adults, according to a press release.

Cases of long COVID are still perplexing medical professionals as they work to figure out what’s causing the prolonged symptoms.

About 25% to 35% of people are estimated to have experienced some form of long COVID after recovering from a COVID-19 infection, according to the Centers for Disease Control and Prevention.

The three treatments being tested hope to help adults suffering from long COVID symptoms such as fast heart rate, dizziness and fatigue, the release said.

The trials are part of the National Institutes of Health’s Researching COVID to Enhance Recovery (RECOVER) Initiative, a nationwide research program to fully understand, diagnose and treat the long-term effects of the coronavirus. 

“As a long COVID patient, I know firsthand how disruptive and frightening symptoms including rapid heart rate, dizziness and fatigue can be,” said Heather Marti, co-chair of the RECOVER National Community Engagement Group. “These trials are giving me and others with long COVID hope that it will restore our health and get us back to the lives we so desire.”

The three potential treatments include Gamunex-C, Ivabradine and Coordinator-guided, non-drug care:

• Gamunex-C is a “form of intravenous immunoglobulin (IVIG) that contains antibodies to help the body protect itself against infection from various diseases and is given by intravenous infusion.”
• Ivabradine is an “oral medication that reduces heart rate.”
• Coordinator-guided, non-drug care is a treatment that includes a series of activities managed through weekly phone calls with a care coordinator.

Researchers plan to enroll 380 total participants at 50 sites across the U.S. The patients will be recruited from surrounding communities and health systems.

People 18 years of age and older who are interested in learning more about these trials can visit https://trials.RECOVERCovid.org/autonomic(link is external) or ClinicalTrials.gov and search identifier NCT06305793, NCT06305806 and NCT06305780. Please do not contact the NIH media phone number or email to enroll in these trials.