How should I counsel a patient about the potential side effects of hormonal contraceptives?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 14 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

When counselling a patient regarding the potential side effects of hormonal contraceptive methods, it is essential to provide detailed verbal and written information to enable them to make an informed choice and use the method effectively ,. This information should be presented in easily understandable language and formats .

Key potential side effects and counselling points include:

  • Venous Thromboembolism (VTE): Advise that there is an increased risk of VTE with combined oral contraceptive (COC) use, with the risk level largely influenced by the progestogen component . For example, 5–7 per 10,000 women using COCs with levonorgestrel, norethisterone, or norgestimate are expected to develop a VTE in one year, compared to 9–12 per 10,000 women using COCs with drospirenone, desogestrel, or gestodene, versus 2 per 10,000 women not using COCs or who are pregnant .
  • Breast Cancer: Inform the patient that studies suggest a small but statistically significant increased risk of breast cancer (up to 24% relative increase), which returns to baseline within 10 years after stopping the COC .
  • Cervical Cancer: Explain that there is a small increased risk after 5 years of COC use and a two-fold increase after 10 years, with the risk returning to baseline 10 years after stopping . Advise women to attend routine cervical cytology screening .
  • Mood Changes: Counsel that depressed mood and depression are known side effects of hormone contraceptive use . Manufacturers state that this can be serious and is a risk factor for suicidal behaviour or suicide . Women should be advised to seek medical help in case of mood changes whilst taking combined oral contraception, including shortly after treatment initiation .
  • Meningioma: Note that the occurrence of meningiomas has been reported in association with the use of cyproterone acetate, especially at high doses and for prolonged periods . If a patient is diagnosed with meningioma, any cyproterone-containing treatment, including co-cyprindiol, must be stopped as a precautionary measure .
  • Angioedema: Inform the patient that symptoms of hereditary and acquired angioedema may be induced or exacerbated by exogenous oestrogens .
  • Menstrual Irregularities: Discuss that menstrual irregularities are a possible adverse effect .
  • Common Misconceptions: Clarify that there is no evidence that COCs cause weight gain or loss of libido .

Additionally, counsel the patient on:

  • Drug Interactions: Advise on the possibility of drug interactions and instruct the woman to check with a healthcare professional before starting any new drug treatment, including herbal remedies such as St John's wort .
  • Managing Vomiting or Diarrhoea: Provide clear instructions on what to do if vomiting or diarrhoea occurs after taking the pill, as this can compromise effectiveness .
  • Adherence: Emphasize the importance of taking the pill regularly at a time of day that will aid adherence .
  • Return to Fertility: Inform the patient that normal fertility returns as soon as the pill is stopped .

Overall, ensure the counselling is sensitive to cultural differences and religious beliefs .

Related Knowledge Topics

Educational content only. Always verify information and use clinical judgement.