This study is testing a treatment called IgPro20 for people with post-COVID POTS. POTS, or postural orthostatic tachycardia syndrome, is a condition where your heart beats very fast when you stand up. This study is "double-blind," meaning neither the participant nor the researchers know who is getting the actual treatment or a placebo (a fake treatment). The study is "randomized," which means participants are chosen by chance to get the treatment or the placebo. "Placebo-controlled" means some people will get the IgPro20, and others will get the placebo, so researchers can see if IgPro20 really works.

• Study Length: Participants will receive multiple doses over a period of time.
• Eligibility: Includes adults diagnosed with post-COVID POTS after having COVID-19.
• Requirements: Participants must not have been treated with certain medications before the study starts.

Before joining, participants should understand the study requires following specific rules, and their health will be checked to ensure they can safely participate. Participants must be 18 or older and have certain test results. Those with certain conditions or infections can't join. It’s important to talk to your doctor and ask questions if you’re interested in participating.