Medical Research & Plasma: Fast Cash Without a Side Hustle Let’s be real — when bills pile up, side hustles don’t always cut it. You need cash, not a six-month dream project. Here’s the truth: medical research studies and plasma donation pay real money, fast. Plasma Donation Paid Medical Research The Honest Side This isn’t glamorous. But it’s legit cash when you need it most. Plenty of people quietly rely on it to keep the lights on or cover bills in a pinch.