Smokers and Non-Smokers: Smoking Cessation Study

Smokers and Non-smokers, 21-65 years old are invited to participate in a research study. The purpose of this research study is to find if smoking cessation combined with Sildenafil will decrease inflammation in the lungs of smokers. We will also be comparing lung imaging and the effects of Sildenafil of smokers with that of non-smokers.
Sildenafil is an FDA approved medication that is approved for many different uses including the treatment of pulmonary hypertension, but it will be given during this study, in a non-FDA-approved manner.


  • will be asked to enter a 3-month smoking cessation program and will have a 50/50 chance of receiving Sildenafil or placebo.


  • will have a 50/50 chance of receiving Sildenafil or will not be taking any study medication during the 3-month time. Study involvement will be four visits over 90 days. The first visit (baseline) last between 5-7 hours. The 30 and 60 day visits will be 1-2 hours, and the last visit will be 4-5 hours.

    The study involves filling out questionnaires, lung function (breathing) tests, CT scans of your lungs with and without contrast dye; blood draws, a urine sample, and for smokers only, a smoking cessation session. If you complete all study procedures and visits you will be paid $425.

Smoker Only - Optional sub-study:

  • If you successfully quit smoking and have no detectable levels of tobacco in your blood at 60 and 90 days, you will receive $400. Requires one additional tube of blood at each visit.


Who can be part of this study?

  • Ages 21-65 years
  • Be willing to attend all clinic visits (4 total)
  • Smokers currently smoking at least one-half pack of cigarettes daily and have a desire to quit smoking.
  • Smokers must be willing to abstain from using nicotine patches, e-cigarettes, or marijuana for the duration of the study.
  • Non-Smokers have never smoked in your entire lifetime

Interested? Please complete the survey to see if you qualify.

Click Here to take our survey.

Actively Recruiting