Guides

Plain answers for people who do paid Phase 1 studies. Same rule here as in our alerts: if we don't know something, we say so. We never guess pay, dates, or eligibility.

These guides describe how US Phase 1 units — Celerion, ICON, Fortrea, PPD, and the rest — generally run things. Clinic and CRO names on this site are always written as text you can read and search, never as a logo you have to recognize. When a rule varies by clinic or by study, the guide says that instead of pretending there is one answer.

• How clinical-trial alternates are chosen

  Why clinics book more people than they dose, how the backup order usually works, and what actually improves your odds of moving from alternate to dosed.

• What is a VCT clinical trial?

  What Verified Clinical Trials checks when you screen, why clinics use it, and why trying to run two studies at once gets caught.

• What is CTSdatabase?

  The other subject-verification database. What it looks for at screening and how it differs from VCT.

• Washout period between clinical trials

  Who sets the gap between studies, how it's counted, and why "30 days" is a common floor rather than a universal rule.

• How is clinical-trial income taxed?

  What volunteers commonly see at tax time — 1099s, not W-2s — and the questions worth taking to a real tax professional. Educational only, not tax advice.