The goal of this study is to conduct a pilot randomized waitlist-controlled trial to assess the feasibility, acceptability, and preliminary effects of substituting the NIDA standardized research e-cigarette (SREC) for combusted cigarettes in MOUD-TUD who are not ready to quit smoking. A waitlist controlled RCT using a mixed-methods sequential explanatory design will investigate the impact of SREC provision on: 1) tobacco use behavior (e.g., cigarettes per day [primary outcome], SREC use), 2) biomarkers (e.g., carbon monoxide, anabasine), 3) cigarette dependence and withdrawal, and 4) short-term health effects and tolerability (e.g., respiratory symptoms, substance use). In the proposed RCT, N=40 adults stable on MOUD with buprenorphine who report daily smoking recruited from MGH primary care practices will be randomly assigned to receive the SREC for 8 weeks, either immediately (iSREC), or after an 8-week delay (waitlist control [WLC]). They will be followed an additional 4 weeks after SREC provision ends (to 12 weeks in iSREC and 20 weeks in WLC).

Inclusion Criteria:

• 18 years of age

  • Report daily cigarette smoking (>=10 cigarettes per day in the past week)
  • Not ready to quit smoking (not planning to quit in the next 30 days)
  • Willing to try e-cigarettes
  • In stable buprenorphine (BUP) treatment for opioid use disorder at an Massachusetts General Hospital-affiliated primary care clinic (in treatment for >=3 months without changes in BUP dose in the past 2 weeks and planning to remain on current BUP treatment for >=3 months).

Exclusion Criteria:

• Pregnant or breastfeeding
• Using non-cigarette nicotine or tobacco products (e.g., e-cigarettes, cigarillos) recently (>3 days in past 30 days)
• Report past 30-day use of behavioral or pharmacologic smoking cessation aids
• Deemed inappropriate for participation by their OUD provider
• Have an unstable psychiatric (e.g., past month suicidal ideation, active psychosis) or medical condition (e.g., life expectancy <1 year).