- Your Age

Every study will be targeted towards a specific age group.  Example:  18 to 55 is common.  May be you'll see 25 to 45 or 65 to 80 or even 6 to 18.

The main age cut-offs are:

   45 for most studies

   55 for many studies

   65 for some studies

   After 65, healthy Phase I studies will be limited but they do occur!

- Your Drinking Habits

Most studies require participants who do not consume alcohol in excess.  Many studies will have "cut-off periods" of 24 to 72 hours before screening and check in.  

- Your Tobacco Habits

Most studies require participants who do not use tobacco products including chewing tobacco and cigarettes.  Some studies do allow lite users, but typically will ban the use of tobacco products during the length of the study.  Note that some studies have "cut-off periods" of varying length.  Many clinics are now doing blood tests for cotinine which is a byproduct of nicotine so it is best to be honest about whether or not you have smoked recently.  Cut-off periods may range from a few days to a year or more. 

- Your Illicit Drug Habits

All healthy volunteer studies require participants who do not use illicit drugs including but not limited to: crack, marijuana, cocaine, heroin and ecstasy.  If you have put drugs behind you, be aware that most drugs can be traced in your system up to 90 days after cessation.  

Many Clinical Research Facilities are implementing "Zero Tolerance" policies which allow them to bar you from participating in future studies if any illicit drugs are found in your system at any time during the study.  This includes during the screening process, during the study and after the study until you have been "cleared" from the study.  

- Your Allergy History

It is necessary for the clinic to know if you are allergic to any drugs, foods or anything else.  Having an allergy doesn't necessarily exclude you from a study, but it is for your safety and health that you report any allergies you may have.  Most studies have a study specific diet and cannot be altered due to food allergies.  As for drug allergies, it is important that you don't do studies with drugs that may cause an allergic reaction. 

- Your Recent Use Of Prescription And Or Over-The-Counter Drug Use

Many studies require participants to not be taking prescription drugs or OTC drugs.  Most studies will have "cut-off periods" of around 30 days.  It is best to be honest if you have taken anything during the "cut-off period."  Anything found in your system that cannot be accounted for will most likely excluded you from the study.  

- Your Recent And Past Medical History

Most Clinical Research Facilities will ask information regarding  your recent medical history.  This can include any hospitalizations due to sickness or physical conditions, surgeries, mental conditions or medical procedures.  Most surgeries will not disqualify you but it's important for the clinic to know your history. 

- Your Ethnicity 

Some studies require a certain ethnic population.  

- Your Family History

Some studies will require subjects with no family history of certain conditions. 

- Your Sex

While many studies require both males and females, some studies will be gender specific i.e. males used for a male enhancement drug and females used for a birth control drug. 

- Your Recent Blood Or Plasma Donations

Depending on how often you donate blood or plasma, you may be asked to wait a period of time before participating in a study.  You will not be allowed to donate blood or plasma during a study and usually for a period of 30 days after you complete a study.

- Your Recent Involvement In A Clinical Research Study

Many volunteers find that they've enjoyed the experience of participating in a study so much that they want to join another study.  Most studies have a "wash-out" of at least 30 days.  That means that once you've completed your last dose in a study, you must wait at least 30 days before participating in another study.  Some studies will require a longer "wash-out" period.  

- Your Body Mass Index (BMI)

Your height and weight are used to determine your BMI.  Many studies recruit participants with a BMI between 18 to 30, but this figure can vary widely.  BMI is your body fat.  Click here to use a BMI calculator.

- Your Ideal Body Weight

Many studies require you to be within a certain percentage.  15% is common.  Click here to use a Ideal Body Weight Calculator.  A study will use either the BMI or IBW but usually not both. 

Multiply the ideal body weight by 15%.  Then subtract your body weight from the ideal body weight.  As long as your weight is equal to or less than 15% or what ever percentage the clinic is looking for, then you should be okay.  Note that this is not a standard test and many clinics may use a different method.  

- International Travel

Many studies will have restrictions against people who have traveled outside the US or country that the study is being conducted in.  This is due to unknown health conditions in foreign countries and especially if you have had any vaccinations or immunizations. 

- Female Restrictions

Some studies will require surgically sterile or post menopausal.  Also, females cannot be pregnant during a clinical research and should not conceive a child for a period of 3 months post study.  

- Your Availability

You must be available for all visits including staying at overnight for one or more consecutive or non-consecutive stays.  You must be available for any and all out-patient visits.  Dates are predetermined and are not negotiable.  If you think you will not be able to make a visit, it is wise not to apply for that study.  Failure to be on time and present for your visits can result in financial penalties.