What is CHC?
CHC = Combined Hormonal Contraception: pill, vaginal ring, hormone patch. All contain oestrogen + progestin. They suppress ovulation and modify mucous membranes and cervical mucus.
Selection criteria
We consider:
- Age, BMI, smoking status
- Migraine (especially with aura — contraindication for oestrogen!)
- Hypertension, thrombosis history (own + family)
- Liver disease
- Breastfeeding (POP instead of CHC)
- Co-existing issues: acne, heavy periods, endometriosis, PMS
You can use our online CHC checklist to prepare for the consultation.
Risks (honest)
- Healthy, non-pregnant non-users of CHC: about 2 VTEs per 10,000 women-years.
- CHC containing levonorgestrel, norethisterone or norgestimate: about 5–7 VTEs per 10,000 women-years.
- CHC containing chlormadinone acetate and ethinylestradiol: about 6–9 VTEs per 10,000 women-years.
- CHC containing dienogest and ethinylestradiol: about 8–11 VTEs per 10,000 women-years.
- CHC containing desogestrel, gestodene or drospirenone with ethinylestradiol: about 9–12 VTEs per 10,000 women-years.
- Vaginal ring or contraceptive patch: about 6–12 VTEs per 10,000 women-years.
Before prescribing, we review factors including your personal and family history, age, BMI, smoking, migraine, blood pressure, immobility and planned surgery. Where risk factors are present, we discuss oestrogen-free alternatives such as a progestogen-only pill, IUD or implant.
Additional benefits
- Regular, often lighter bleeding
- Reduction of acne and unwanted hair growth (PCOS)
- Reduction of menstrual pain and endometriosis symptoms
- Reduced risk of ovarian and endometrial cancer (long-term use)
Correct use
- Pill: every day at the scheduled time stated in the package leaflet
- Ring: 21 days in, 7 days break
- Patch: weekly change, 3 weeks, 1 week break
- Long cycles possible — we counsel
Missed pill — what to do?
Take the missed tablet as soon as you notice and immediately check the package leaflet for your specific product. The safe catch-up window and how long additional contraception is needed depend on the active ingredient, the number of tablets missed and when this occurred in the cycle — there is no universal 12-/24-hour rule or blanket 7-day rule. If unprotected sex has occurred, emergency contraception can be time-sensitive. Please therefore ask the practice or a pharmacy for advice the same day; when unsure: 044 525 20 60.
Sources: Swissmedic — combined hormonal contraceptives · Swissmedic — current risk table (German) · SGGG — Expert Letter No. 79 (German) · Last updated: July 2026 · These notes do not replace individual medical advice.