Phase I - Types of Studies for Healthy Volunteers

Clinical trials in Phase I are used to determine the safety, tolerability, and pharmacokinetics (how your body absorbs, metabolizes, and excretes) of a drug.

There are a variety of study types that are conducted at our clinics. Sometimes, a study is a combination of multiple study types. These study types include:

Bioavailability (BA)

  • The rate and extent to which a drug is absorbed or is otherwise available to the treatment site in the body.

Bioequivalence (BE)

  • Drugs with the same active ingredient(s) are compared at the same dosage under similar conditions.

Drug-Drug Interaction

  • A modification of the effect of a drug when administered with another drug. Drugs with the same active ingredient(s) are compared at the same dosage under similar conditions.

First in Human (FIH)

  • The first Phase I study in which the test product is administered to human beings. These usually have a small group dosed followed by a larger group after safety is assessed.

Single ascending Dose or Multiple ascending dose (SAD/MAD)

  • Single Ascending Dose: subjects are dosed in small groups. Each member of the group will receive either the drug or placebo. The first group will start with a very low dose, each following group will receive an escalated dose depending on the safety and tolerability of the drug. The dose escalation will stop once maximum tolerability and/or safety has been reached.
  • Multiple Ascending Dose: Similar to ascending except subjects will receive multiple doses of the drug or placebo instead of just one.

Food Effect (FE)

  • Assessing the effects of food on the rate of absorption of a drug when the drug product is administered shortly after a meal as compared to fasted conditions.

Pharmacodynamics (PD)

  • Studies the biochemical and physiologic effects of the drug
    • Desired activity (Main use of drug)
    • Undesirable effects
    • Therapeutic window
    • Duration of action of the drug on the body

Pharmacokinetic (PK)

  • Assessing the body’s absorption, distribution, metabolism, and excretion of the drug. In other words, how your body affects the drug.


  • The QT interval is a measure of the time between the start of Q wave and the end of the T wave in the hearts electrical cycle. QT studies assess the drug’s effect on the QT interval under a strictly controlled environment. To analyze the affects, frequent electrocardiogram (ECG) recordings are collected to monitor QT changes.

AME (Radiolabeled) – Madison Clinic Only

  • These studies assess radioactivity levels through absorption, metabolism, and excretion. These components are measured through collection of blood, fecal, and urine samples.
  • Read more on Radiolabeled AMEs

Get started today. Fill out a brief form and we'll follow up to see if you qualify for a study. Or call us directly at 866-429-3700.

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