Last Tuesday, during my lunch break, I went to a clinic to participate in a clinical trial. I'm not sick, nor do I have any health mysteries. I'm one of the thousands of people each year who participate in clinical trials as healthy volunteers. Not because I ran out of treatment options or want to be the first to access a new drug, but because researchers need to know what a drug does to a body that isn't already compromised by illness.
Most people don't know this kind of participation exists, let alone that anyone can participate. Here's why healthy volunteers matter, what kinds of trials actually need them, what my experience was like, and how you too can participate.
What Types of Trials Need Healthy Volunteers?
Every medical device, vaccine, treatment, or diagnostic tool has to pass through human testing before it becomes available to the people who need it. That's where healthy volunteers can help. They are someone with no diagnosed mental or physical health conditions who volunteers their time and body to serve as a baseline group.
There are 5 main types of studies that use healthy volunteers in the process.
1. Phase I Trials
A phase 1 trial is the first time a new medical treatment or drug is tested in humans. It focuses on safety, finding the right dose, and checking for side effects while understanding how a drug is absorbed, distributed, metabolised, and excreted by the human body.
At this stage, healthy volunteers are needed to observe the drug's effects without interference from pre-existing illnesses or other medications that could mask dangerous side effects. However, high-risk treatments like cancer or advanced diseases use sick patients instead, because the drugs are too toxic for healthy bodies. These trials usually enrol between 20 and 100 people to produce statistically meaningful results.
Unlike later stage trials, there's usually no placebo in a Phase 1 trial. Every participant gets the drug, just at different dosage levels.
The time commitment as a volunteer can last anywhere from 1 month to over a year and can be either inpatient or outpatient. Although each trial differs, researchers will commonly take blood and urine samples, monitor heart rate and blood pressure, and take ECG scans to monitor the heart. Not only does this data help them publish research, but it also protects you by keeping a close eye on what's happening in your body.
2. Bioequivalence Studies
Bioequivalence studies compare how fast and how much of a drug's active ingredient enters the bloodstream from two different products. This usually compares a new generic drug to an original brand-name drug to prove they work the same way in the body.
Healthy volunteers are used in these studies to reduce biological variation and clearly compare how the human body absorbs two different versions of a drug. A recent trial tested the bioequivalence of Advil PM Liqui-Gels and Advil PM Liqui-Gels Minis, the same formulation in a different sized capsule.
The active clinical phase of a bioequivalence study typically takes 1 to 4 weeks. It involves an initial screening, dosing appointments and/or clinic stays, and a final follow up visit.
3. Behavioral, Sleep, and Nutrition Studies
Not every study involves a drug or device. Research into how activity, light exposure, diet, or sleep patterns affect mood and cognition also depends on healthy volunteers. These studies establish a normal baseline for things like circadian rhythm, appetite, or attention, often by tracking participants over days or weeks rather than dosing them with a drug.
This type of study tends to be less invasive than drug trials, which makes it a common starting point for people curious about volunteering but wary of anything involving needles or medication.
4. Vaccine Trials
Vaccines are inherently given to healthy people preventively, so it makes sense that they're tested on healthy people from the start. Early-phase vaccine trials assess whether a vaccine triggers the right immune response and what side effects show up, before ever testing it in a larger, more vulnerable population. A recent example is Pfizer's vaccine for COVID-19, published in 2020.
While initial screening and injection appointments usually take a few hours spread across 2 weeks, follow up visits can continue for a few months.
5. Diagnostic and Device Studies
When researchers develop a new blood test, imaging technique, or medical device, they need to know what a healthy result looks like before they can identify an abnormal one. Healthy volunteers become the reference point that patient data is compared against, usually matching people by age and sex to make that comparison meaningful.
This is the type of trial that I was involved in.
What It's Actually Like to Be a Healthy Volunteer
July 8: I used MyTrials.ai's healthy volunteer option to get matched to clinical trials that are in my area and recruiting for participants. That same day, I requested to contact a trial and got an email to book my initial screening call.
July 9: I hopped on a 30 minute virtual call with the study coordinator, where she asked questions to confirm my eligibility and told me a bit more about the study. She explained that they are testing the efficacy of a new high-sensitivity troponin I (hs-TnI) test. It measures small amounts of the cardiac protein troponin I in your blood, used to quickly check for heart muscle damage, commonly to help diagnose or rule out a heart attack. On this call, I read over the study brief and signed the consent form before she walked me through booking an appointment at my local clinic. I also had the opportunity to ask her questions about the procedure and study.
July 28: During my lunch break, I walked to my nearest clinic, handed them my lab requisition form, and got my blood drawn.
July 30: I received a $25 Amazon gift card as compensation for my time.
The entire process, from looking for the trial, getting screened, and completing the blood draw, took me an hour spread across 3 weeks.
It's easy to think of clinical trials as something that only involves sick patients desperate for a new treatment. In reality, the whole pipeline depends on healthy people who are willing to give their time and body to research; not because they're getting treated for anything, but because someone has to go first. That could be a student earning some extra money over a long weekend, a retiree with flexible time, or, in my case, someone who was just curious.
How You Can Become a Healthy Volunteer Too
Start with a trial-matching platform.
MyTrials.ai uses AI to match you to trials based on your profile rather than making you dig through listings yourself. While it was built primarily for patients to search by condition, the new "healthy volunteers" feature matches you to trials looking for healthy individuals. It translates the study's purpose from complex medical terminology to plain English, making it more accessible and faster than combing through raw databases like clinicaltrials.gov.
Expect a screening process.
Every trial starts with an eligibility check. In my case, it was a virtual call, but others may require an in-person visit with bloodwork, an EKG, and a review of your medical history. This is as much about protecting you as it is about controlling variables in the study. Researchers are ruling out anything that could put you at risk or skew the data.
Ask questions before you sign.
What's the time commitment? What are the known risks and side effects? Is there compensation? Can you withdraw at any point, and what happens if you do? A legitimate trial will have a detailed informed consent document and won't rush you to commit.
Start small if you're unsure.
A diagnostic study, like the trial I did, or a short observational study (sleep, nutrition, behavior) is a lower-commitment way to see what the experience is actually like before considering something longer or more involved.