For quite some time pharmaceutical companies seek clinical trial volunteers

Obviously if you have a terminal disease & you are invited to the trial, you could be cured, so no payment there, as it could prolong your life. But you could become a clinical trial volunteer as your average Joe/Jane

They pay anything from 800 & 4k depending the length of the trial & what is involved

You go for screening to see if you are suitable for one day then after that you spend Wednesday to Sunday in the ward; half of you given the drug; the other half being given a placebo. You don't know what group you are in

After the stay you have six follow up visits every second day to see if you have any after effects. Then they bung you the check

To participate you can't have donated blood in six months before the trial and you can only donate blood after the trials for another six months