NCT04521647.

Study name	Effects of menthol in e‐cigarettes on smoking behaviors
Methods	Randomized cross‐over Setting: Connecticut Mental Health Center, USA
Participants	Estimated enrolment 85 Inclusion criteria: ≥ 21 years, use combustible cigarettes Exclusion Criteria: None
Interventions	EC: type not stated Arm 1: menthol flavour. Participants will receive 5% nicotine in an EC. Participants will receive 2 nicotine concentrations via EC. Each exposure will be 10 3‐sec puffs and ad libitum use. Arm 2: tobacco flavour. Participants will receive 5% nicotine in an EC. Participants will receive 2 nicotine concentrations via EC. Each exposure will be 10 3‐sec puffs and ad libitum use.
Outcomes	Baseline and 2, 5, 15, 30, 45, 60, 90, 120, and 180 minutes after nicotine exposure (plasma nicotine levels), 2 weeks (CO), 3 weeks,  5 weeks  (BP and heart rate) Primary outcomes: Cigarette craving; plasma nicotine levels; carbon monoxide Secondary outcomes: EC craving; irritation/harshness; liking of EC; coolness; nicotine withdrawal; stimulation; EC use; cigarette use. Other outcomes measured: heart rate, blood pressure, pulse oximetry
Starting date	Study start date: November 1 2020. Estimated completion date: July 2025
Contact information	Asti Jackson, PhD 4752414904, asti.jackson@yale.edu
Notes	New to 2022 update