Based on PubMed | Does smoking increase the risk of polycystic ovary syndrome or worsen its symptoms?

Smoking does not appear to cause polycystic ovary syndrome (PCOS), but it may worsen some metabolic and hormone features in those who already have PCOS. Studies in women with PCOS suggest that smoking is linked to higher “free” testosterone, worse insulin resistance, and a less healthy cholesterol profile, even though it does not clearly change menstrual patterns or ultrasound findings of the ovaries. ^{[1] [2]}

What the research suggests

• Insulin resistance and androgens: In a cohort of women with PCOS, smokers had higher fasting insulin and higher free testosterone (calculated free testosterone and free androgen index), pointing to aggravated insulin resistance compared with nonsmokers. Clinical signs such as hirsutism, acne, menstrual regularity, and ultrasound-defined polycystic ovaries did not differ between smokers and nonsmokers in that analysis. ^[1]
• Cholesterol and adrenal hormones: In another large series of women with PCOS, smokers showed a more adverse fasting lipid profile (higher total cholesterol, LDL, and triglycerides; lower HDL) and higher adrenal steroid responses (elevated 17‑hydroxyprogesterone at baseline and after ACTH stimulation), with lower prolactin levels. Body composition and insulin resistance measures were not different in that study, but the lipid changes favor a higher cardiometabolic risk. ^[2]

What this means for you

• Risk of developing PCOS: Current high‑quality clinical guidance does not list cigarette smoking as a proven cause or direct risk factor for developing PCOS. PCOS is thought to arise from a mix of genetic predisposition and hormonal/metabolic factors rather than smoking itself.
• Worsening certain features if you already have PCOS: Evidence points to smoking being associated with higher androgens, worse insulin measures, and unfavorable cholesterol patterns in women with PCOS, which can matter for long‑term heart and metabolic health. However, smoking has not consistently been linked with more irregular periods, worse acne/hirsutism scores, or more “cysts” on ultrasound. ^{[1] [2]}
• Overall health context: Because PCOS already raises risks for issues like metabolic syndrome, type 2 diabetes, and cardiovascular disease, any added negative effect from smoking on lipids and insulin can compound long‑term risk, even if it doesn’t change ovulation patterns. ^{[1] [2]}

Practical takeaways

• Quitting helps your metabolic health: For someone with PCOS, stopping smoking is a practical step that may reduce cardiovascular risk by improving lipid patterns and insulin sensitivity over time, on top of the many general benefits of quitting. ^{[1] [2]}
• Focus on modifiable factors: Along with smoking cessation, strategies such as regular physical activity, balanced nutrition aimed at weight management, and adequate sleep can help improve insulin resistance and androgen levels, which often improves symptoms like irregular cycles and acne.
• Medication considerations: If you use combined oral contraceptives for cycle control or acne, keep in mind that smoking increases the risk of serious heart and blood‑vessel side effects with these pills, especially at age 35+ and with heavier smoking, so avoiding smoking is strongly advised when using estrogen‑containing contraception. ^[3]

Bottom line

• Cause: Smoking is not clearly a cause of PCOS.
• Worsening: Smoking is linked with worse metabolic and some hormone markers in women with PCOS, potentially increasing long‑term cardiometabolic risk, while clinical symptoms like periods or ultrasound appearance may not change much. Quitting smoking is a meaningful step to support overall health in PCOS. ^{[1] [2] [3]}

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Quick reference table

Question	What evidence shows
Does smoking cause PCOS?	No clear evidence that smoking causes PCOS; PCOS is largely genetic/hormonal in origin.
Does smoking worsen PCOS features?	Yes, it is associated with higher free testosterone and worse insulin resistance in some cohorts. [1]
Impact on cholesterol?	More adverse lipid profile in smokers with PCOS (↑LDL, ↑triglycerides, ↓HDL). [2]
Impact on periods/ovulation or ovarian ultrasound?	No consistent differences between smokers and nonsmokers in cycles, hirsutism/acne scores, or ultrasound criteria. [1]
Safety with birth control pills?	Smoking raises risk of serious heart/vascular side effects with combined oral contraceptives, especially ≥35 years and heavy smoking. [3]