Progestogen / hormone replacement
Progesterone and smoking: how tobacco affects the medication
Tobacco smoking is one of the most underappreciated drug-drug interactions in chronic medication. Compounds in tobacco smoke induce hepatic enzymes (especially CYP1A2) and can shift the plasma concentration of many medications, including Progesterone (Progesterone), enough to matter clinically at 100mg, 200mg.
How smoking affects Progesterone
Polycyclic aromatic hydrocarbons in tobacco smoke induce CYP1A2 and to a lesser extent other CYP enzymes. For medications metabolised primarily by CYP1A2, smokers can have plasma levels 30–50% lower than non-smokers at the same dose. Whether Progesterone is affected depends on its specific metabolic pathway. Progesterone binds to progesterone receptors and modulates gene expression in reproductive and other tissues.
Practical guidance
According to the prescribing information for Progesterone, smoking status should be disclosed at every dose review of Progesterone. Stopping smoking can paradoxically raise plasma levels of CYP1A2-metabolised medications enough to cause new-onset side effects within days, and may require a temporary dose reduction. The 100mg, 200mg starting strength assumed in the prescribing information is usually for non-smokers.
Frequently asked questions
Does smoking change how Progesterone works? ▾
For medications metabolised by CYP1A2, yes — smokers may need higher doses or have reduced effect at standard 100mg, 200mg. Whether Progesterone specifically is affected depends on whether Progesterone uses CYP1A2. The prescribing information notes any documented interaction.
Will I need to adjust Progesterone if I quit smoking? ▾
Possibly, if Progesterone is one of the medications affected by CYP1A2 induction. Stopping smoking restores CYP1A2 to normal within days, raising plasma levels and potentially causing side effects. Discuss the timing of any dose adjustment with the prescriber when planning to quit.
Products containing Progesterone
More on Progesterone
- With alcoholProgesterone and alcohol — is it safe to drink?
- With foodShould Progesterone be taken with food?
- Side effectsProgesterone side effects: common, rare and warning signs
- Dosage guideProgesterone dosage guide: how much to take and when
- OnsetHow fast does Progesterone start working?
- DurationHow long does Progesterone last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.