The purpose of the study is to learn about an herbal product called Hoodia gordonii. We
want to know if Hoodia gordonii affects blood pressure, heart rate (pulse), heart pressures,
and the heart's electrical conduction system. To participate in this study you must be a
healthy volunteer with no known medical problems.
If you decide to join this research study you will come in for two visits one week apart.
Each visit will last 8 hours (you will not be required to stay in the exam room for the
entire day). During the first visit you will be assigned, by chance, like the flip of a
coin, to get either Hoodia gordonii or placebo. A placebo is a pill that looks like the
herbal supplement but does not have any active ingredients in it. During the second visit
you will get either Hoodia or placebo, whichever you did not get during the first visit.
Neither you nor your study doctor will know ahead of time if you will get Hoodia or placebo
during the first visit.
If you choose to participate in this study you have the following tests performed.
A. Electrocardiogram (ECG): this is a test that measures the electrical activity in the
heart. This test involves placing 10 stickers on the chest and stomach and will last about
B. Blood Pressure: this is a test that involves placing a cuff on your arm and inflating it.
Blood pressure cuffs might make you feel uncomfortable when they inflate, but it is not
painful. The cuff will be placed on your arm for approximately 3 minutes.
C. Hemodynamics: these are tests that measure the pressures in the heart. This test
involves placing 4 stickers (2 on your neck and 2 on your stomach) and is done while lying
down. This test will last about 3 minutes and will be done at the same time as the blood
Each test (A through C) will be performed a total of 10 times (5 times each study visit).
Women of child bearing age will be required to take a urine pregnancy test. Pregnant women
are not eligible to participate in this study. An outline of a study day is provided below.
1. Arrive at the exam room. ECG, Blood Pressure, and Hemodynamics are measured (for
2. Take the study pill (for example, 8:15am).
3. Return to exam room 1 hour after taking the study pill to have ECG, Blood Pressure, and
hemodynamics measured (for example, 9:15am).
4. Return to the exam room 3 hours after taking the study pill to have ECG, Blood
Pressure, and hemodynamics measured (for example, 11:15am).
5. Return to the exam room 5 hours after taking the study pill to have ECG, Blood
Pressure, and hemodynamics measured (for example, 1:15pm).
6. Return to the exam room 8 hours after taking the study pill to have ECG, Blood
Pressure, and hemodynamics measured (for example, 4:15pm).
Return to exam room 1 week later and repeat the day outlined above. Your participation in
this study will last 1 week.
- Subjects at least 18 years of age and in general good health expressing interest in
participating in the study will be evaluated for inclusion.
- baseline heart rate less than 50 beats/minute or greater than 100 beats/minute
- heart rhythm other than normal sinus
- history of atrial or ventricular arrhythmia
- family history of premature sudden cardiac death
- left ventricular hypertrophy
- T-wave abnormality
- baseline corrected QT(QTc) interval greater than 440 milliseconds (ms)
- thyroid disease
- type 1 or 2 diabetes mellitus
- recurrent headaches
- any psychiatric condition or neurological disorder
- history of alcohol or drug abuse
- renal or hepatic dysfunction
- concurrent use of potentially interacting drugs (anticoagulants, MAO inhibitors, CYP
3A impacted drugs (substrate, inducer, or inhibitor) over the counter medications
containing pseudoephedrine, caffeine containing products, or any dietary supplements)
- subject unwillingness to sign informed consent
- Pregnant or lactating females will also be also excluded from participation with
urine dipstick tests used to confirm lack of pregnancy.