Smoking Cessation and Menstrual Cycle Phase

This study investigates whether the phase of a woman's menstrual cycle affects her success in quitting smoking. Researchers will assign women to quit on a specific day of their cycle (either the follicular or luteal phase) to see if one phase leads to better quitting outcomes with nicotine replacement therapy (patches and gum/lozenge). **You may be eligible if...** - You have regular menstrual cycles (21–35 days long) - You smoke at least 5 cigarettes per day and have done so for the past 6 months - You intend to quit smoking within the next 30 days - You are willing to use nicotine patches and gum or lozenge to help quit - You have a valid email address for study communications **You may NOT be eligible if...** - You are currently using hormonal treatments (birth control pills, progesterone, estrogen, or fertility drugs) - You are pregnant or planning to become pregnant - You are currently taking prescription medications specifically for smoking cessation (like varenicline/Champix) - Your menstrual cycles are irregular - You do not intend to make a quit attempt Talk to your doctor to see if this trial is right for you.