The purpose of this study is to examine the effect of number of cigarillos per package on use behaviors, intensity of use and biomarkers of exposure.

This laboratory-based study will aim to enroll 50 current cigarillo users to complete a 20-day, randomized, parallel design protocol. After a 5-day period of smoking their own preferred brand of cigarillos, participants will begin a 15-day experimental period when they will be randomized to one of two conditions, 2 cigarillos per pack versus 4 cigarillos per pack, to examine how quantity per pack affects use patterns, including daily consumption and cigar smoking topography. Participants will be asked to attend 2 in-person sessions on Days 5 and 20. On Days 0, 9, 12 and 16 participants will complete sessions with research staff remotely (i.e. by phone or video call). Sessions will occur every 3-5 days, for a total of 6 sessions across 20 days.

Inclusion Criteria:

• Current cigarillo smoker (i.e., smoked at least 50 cigarillos in their lifetime)
• Not currently undergoing smoking cessation treatment or planning to quit smoking over the duration of the study (~3 weeks).
• Plan to live in the area for the duration of the study.
• Willing to use study provided cigarillos.
• Capable of giving informed consent, which includes compliance with the requirements and restrictions listed in the combined Informed Consent and HIPAA form.
• Able to communicate fluently in English (i.e., speaking, writing, and reading).

Exclusion Criteria:

• Use of any nicotine-containing products other than cigarillos or cigarettes. Participants reporting isolated use of other nicotine containing products less than 5 times per month are eligible to participate.
• Current or impending enrollment in a smoking cessation program. Further, participants will be excluded for an attempt to quit smoking over the duration of the study period.
• History of substance abuse (other than nicotine dependence) in the past 12 months and/or currently receiving medical treatment for substance abuse. Attendance at alcoholics anonymous or narcotics anonymous meetings will not be considered medical treatment for the purposes of this protocol.
• Current alcohol consumption that exceeds 25 standard drinks/week.
• Women, including all individuals assigned as "female" at birth, who are pregnant, breast feeding, or planning a pregnancy over the duration of the study period.
• Any impairment including, but not limited to, visual, physical, and/or neurological impairments preventing the proper completion of the study procedures. Notable impairments will be evaluated on a case-by-case basis by the Principal Investigator and/or the Study Physician.
• Serious or unstable medical condition. Applicable conditions will be evaluated on a case-by-case basis by the Principal Investigator and/or the Study Physician.
• Lifetime history or current diagnosis of COPD, cardiovascular disease, or heart attack.
• Lifetime history of schizophrenia, psychosis, and/or bipolar disorder.
• Current diagnosis of active major depression. Participants who maintain a diagnosis of major depression who have not experienced any major depressive episodes in the past 6 months and are stable on antidepressant medication(s) are eligible to participate.

Additional, general reasons for exclusion include:

• Past, current, anticipated, or pending enrollment in another research program over the study period that could potentially impact subject safety, study data, and/or the study design as determined by the Principal Investigator and/or Study Physician.
• Any circumstance, medical condition, illness, disorder, adverse event (AE), or concomitant medication that could compromise participant safety or significantly impact study performance as determined by the Principal Investigator and/or Study Physician. Participants may be withdrawn for any of the aforementioned reasons at any point throughout the study.
• Significant non-compliance with protocol and/or study design as determined by the Principal Investigator and/or Study Physician. Participants may be withdrawn at any point throughout the study.

Deidentified study data will be made available to other researchers who contact the project Principal Investigator via email. Data will be available to such requests 1 year after the conclusion of recruitment.

1 year after the conclusion of recruitment.

Researchers should contact the Principal Investigator via email.

Participants will be informed that they will be supplied with study cigarillos, but will be unaware of their randomization condition, 2 cigarillos per pack versus 4 cigarillos per pack.