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Combined oral contraceptive pill - follow-up and common problems

Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the The combined oral contraceptive (COC) pill article more useful, or one of our other health articles.

Good practice for the first prescription of the combined oral contraceptive (COC) pill is described in the separate article Combined Oral Contraceptive Pill (First Prescription). This article covers good practice for follow-up, safe ongoing prescribing and issues which may be encountered in doing so.

Continue reading below

When to follow up

After the first prescription, review at three months. If all is well, follow up at 6- to 12-monthly intervals. Supplies of up to a year may be issued.

Stress to the woman that she should return earlier if she develops any problems or side-effects, or if she has any concerns.

What to do in the follow-up consultation

  • Ask:

    • Has she found it easy to use/remember?

    • Has she noticed any adverse effects?

    • Does she understand how to take it?

    • Does she know how to manage missed pills?

    • Has the pattern of withdrawal bleeds been regular?

    • Has there been any breakthrough bleeding (BTB)?

    • Have there been developments in her medical history (eg, new medication) or social history (eg, age and smoking) which need to be considered.

  • Examination:

    • Check blood pressure.

    • Measure body mass index (BMI)

  • Consider whether contraception is still required and if the combined pill is still the most appropriate and the safest method.

  • Check whether cervical screening is due.

  • Give the patient the opportunity to ask questions

Continue reading below

Common problems

Breakthrough bleeding (BTB)

See the separate article Breakthrough Bleeding with Combined Hormonal Contraception. Women should be advised that this can occur with the COC pill, most commonly in the first few months. If there has been no vomiting or diarrhoea and there have been no missed pills, it has not been shown to indicate reduced efficacy. Consider sexually transmitted infections, pregnancy, missed pills, and malabsorption as possible causes, but BTB is a common side-effect.

Weight gain

Cochrane reviews have consistently failed to show any evidence that significant weight gain is a side-effect of the pill1 .


There are many commonly used medications which can affect the efficacy of the pill:

  • Antibacterials - enzyme inducers only (eg, rifampicin, rifabutin).

  • Antidepressants - St John's wort (which can be bought over the counter).

  • Anticonvulsants - carbamazepine, oxcarbazepine, eslicarbazepine, phenobarbital, phenytoin, primidone and topiramate, due to their enzyme-inducing activity. Also lamotrigine which has a specific safety warning - there is an increased risk of seizure whilst taking the COC pill with lamotrigine, and a risk of toxicity during the pill-free week, when levels rise. Therefore, risk may outweigh benefit (UKMEC category 3).

  • Antiretrovirals - in particular, ritonavir-boosted protease inhibitors.

  • Ulipristal acetate (the 'morning after pill' ellaOne®).

Type of medication

Advice given

Non-enzyme-inducing antibacterial.

Women should be advised that no additional contraception is required.

Short course (two months or less) of enzyme-inducing antibacterials rifampicin or rifabutin.

Women are advised to continue taking the COC pill and use additional precautions. Monophasic 21-day pills should be taken either as an extended regimen (continue packets without a break until 3-4 days of BTB occurs, then have 4-day pill-free interval) or a tricycling regimen (three packets without a break then a 4-day pill-free interval). Additional contraception should be continued for 28 days after stopping the rifampicin/rifabutin.

Long-term course of enzyme-inducing antibacterials rifampicin or rifabutin.

Should be advised to use an alternative, non-hormonal method where possible (very potent enzyme inducers).

Other enzyme-inducing drugs, including anticonvulsants, St John's wort, etc.

Short course: advice is as per that above for rifampicin/rifabutin. Long course: women should be encouraged to use alternative methods of contraception. If, having considered alternatives, they still choose the COC pill, the patient should be advised of the increased risk of pregnancy. Should use a preparation containing at least 50 micrograms of oestrogen. Tricycling or extended regimens as above should be used. If BTB occurs on 50 micrograms, the dose should be increased to a maximum of 70 micrograms.


Women should be advised not to take lamotrigine with the COC pill and should seek another form of contraception (unless also taking a non-enzyme-inducing anticonvulsant such as sodium valproate).

Antiretroviral therapies.

Those women on ritonavir-boosted protease inhibitors should be advised to use alternative methods of contraception.

Ulipristal acetate.

Women should be advised to start the COC 5 days after taking ulipristal acetate, and to use a barrier method of contraception (such as condoms) for this time and the next 7 days (9 days if taking Qlaira®.

Women on medication which may interact with the contraceptive pill should be advised to carry out a pregnancy test and seek medical advice if there is a very light or no withdrawal bleed. They should also seek advice if they have BTB, which may indicate reduced efficacy in this situation.

Other medications may cause lack of efficacy of the contraceptive pill by causing side-effects such as diarrhoea or vomiting. Women on the anti-obesity pill orlistat who experience severe diarrhoea, for example, are advised to use additional contraceptive precautions as there is a theoretical risk of lack of absorption.

Concomitant administration of the COC pill with some medications may increase levels. This may be the case with theophylline, and levels should be monitored. Tacrolimus levels may also be increased, and effect should be monitored.

Diarrhoea and vomiting

  • Vomiting within two hours of taking the pill, or very severe diarrhoea, can affect the absorption of the pill.

  • The advice for women who experience vomiting or diarrhoea for more than 24 hours is to follow the same advice as if they had missed pills.


For any woman on the COC pill about to undergo a major elective operation, the risk of thromboembolism needs to be balanced with the risk of unwanted pregnancy. Usually the COC pill would be discontinued four weeks before elective major surgery and restarted on day one of the next period, occurring at least two weeks after mobilisation2 . Progestogen-only contraception can be offered as an alternative during this time.

Women requiring emergency surgery should receive subcutaneous heparin and compression stockings.

This does not apply to women having minor surgery where there are short periods of anaesthesia, such as tooth extractions or laparoscopic sterilisation.


  • There can be amenorrhoea following cessation of using the COC pill. This is usually due to the pill's withdrawal bleeds masking an underlying problem.

  • Any amenorrhoea lasting more than six months after stopping the pill should be investigated as for secondary amenorrhoea.

Mature women

This is detailed in the separate Contraception from 40 to the Menopause article.

Other uses for the combined hormonal contraceptive pill

Menorrhagia and dysmenorrhoea

  • In women with heavy and/or painful menses the COC pill has been shown to be beneficial. There is evidence for its efficacy in reducing menorrhagia, similar to mefenamic acid3 . There is weak evidence for its efficacy for primary treatment of dysmenorrhoea4 . There is no evidence for benefit of one type of COC pill being better than any other.

  • It can also make the cycle more manageable by running packs together, and in avoiding the pill-free week, women can avoid the withdrawal bleed. This is particularly useful for travel, but also for athletes. It is good practice to advise women that they can manipulate their cycle in this way.

Polycystic ovary syndrome (PCOS)5

  • Women who have PCOS are often oligo-amenorrhoeic.

  • Endometrial cystic hyperplasia is associated with prolonged periods of anovulation, as found in PCOS.

  • There is an association between PCOS and endometrial hyperplasia and carcinoma. They should be offered protective therapy from prolonged exposure to relatively unopposed oestrogen. The COC pill does this effectively, as well as providing contraception. However, cardiovascular risks should be taken into account, as women with PCOS are also at risk of the metabolic syndrome, and may be more likely to be overweight.

  • The COC pill may be superior to metformin for controlling hormonal effects of PCOS (eg, hirsutism), but evidence reviewed is generally low in quality6 .


  • Randomised controlled trials have shown significant improvements in acne vulgaris whilst using the COC pill.

  • This evidence is specific for preparations containing the progestogens levonorgestrel and norethisterone. There is no consistent evidence to support the use of any particular pill as being more effective than another for this purpose.

  • Dianette® is also indicated for use in acne or moderately severe hirsutism. It should be withdrawn if there is no improvement after three months of use. Dianette® carries a 50-80% greater risk of venous thromboembolism (VTE) than COC pills containing levonorgestrel, but no higher than those containing gestodene, desogestrel, or drospirenone with 30-35 micrograms of ethinylestradiol8 .

Reducing the risk of cancer

  • The pill has been shown to reduce the risk of ovarian, endometrial, and colorectal cancer, and lymphatic and haematopoietic cancer9 .

  • The risk reduction is most significant for ovarian cancer. For every five years of use, there is a 20% reduction in the risk of ovarian cancer, and after 15 years of use a woman's risk is half that of a woman who has never taken the pill10 .

  • There is currently insufficient evidence for the use of the COC pill for the primary prevention of ovarian cancer. Modelling suggests that BRCA mutation carriers should consider using the oral contraceptive pill for chemoprevention11 .

  • An increased risk of breast cancer seen in current and recent users seems to be lost within approximately five years of stopping oral contraception, with no evidence of increased risk in 'ever' users with time9 . For BRCA1 and BRCA2 mutation carriers, the association between COC pill use and breast cancer risk is still unclear, so indications other than contraception should be avoided and non-hormonal contraceptive methods should be discussed12 .

Further reading and references

  1. Gallo MF, Lopez LM, Grimes DA, et al; Combination contraceptives: effects on weight. Cochrane Database Syst Rev. 2014 Jan 29;1:CD003987. doi: 10.1002/14651858.CD003987.pub5.
  2. Combined hormonal methods; NICE CKS, January 2021 (UK access only)
  3. Lethaby A, Wise MR, Weterings MA, et al; Combined hormonal contraceptives for heavy menstrual bleeding. Cochrane Database Syst Rev. 2019 Feb 11;2:CD000154. doi: 10.1002/14651858.CD000154.pub3.
  4. Wong CL, Farquhar C, Roberts H, et al; Oral contraceptive pill for primary dysmenorrhoea. Cochrane Database Syst Rev. 2009 Oct 7;(4):CD002120. doi: 10.1002/14651858.CD002120.pub3.
  5. Long-term Consequences of Polycystic Ovary Syndrome; Royal College of Obstetricians and Gynaecologists (November 2014)
  6. Fraison E, Kostova E, Moran LJ, et al; Metformin versus the combined oral contraceptive pill for hirsutism, acne, and menstrual pattern in polycystic ovary syndrome. Cochrane Database Syst Rev. 2020 Aug 13;8:CD005552. doi: 10.1002/14651858.CD005552.pub3.
  7. Arowojolu AO, Gallo MF, Lopez LM, et al; Combined oral contraceptive pills for treatment of acne. Cochrane Database Syst Rev. 2012 Jul 11;7:CD004425. doi: 10.1002/14651858.CD004425.pub6.
  8. de Bastos M, Stegeman BH, Rosendaal FR, et al; Combined oral contraceptives: venous thrombosis. Cochrane Database Syst Rev. 2014 Mar 3;3:CD010813. doi: 10.1002/14651858.CD010813.pub2.
  9. Iversen L, Sivasubramaniam S, Lee AJ, et al; Lifetime cancer risk and combined oral contraceptives: the Royal College of General Practitioners' Oral Contraception Study. Am J Obstet Gynecol. 2017 Jun;216(6):580.e1-580.e9. doi: 10.1016/j.ajog.2017.02.002. Epub 2017 Feb 8.
  10. Beral V, Doll R, et al; Collaborative Group on Epidemiological Studies of Ovarian Cancer. Ovarian cancer and oral contraceptives: collaborative reanalysis of data from 45 epidemiological studies including 23,257 women with ovarian cancer and 87,303 controls. Lancet. 2008 Jan 26;371(9609):303-14.
  11. Menon U, Karpinskyj C, Gentry-Maharaj A; Ovarian Cancer Prevention and Screening. Obstet Gynecol. 2018 May;131(5):909-927. doi: 10.1097/AOG.0000000000002580.
  12. Schrijver LH, Olsson H, Phillips KA, et al; Oral Contraceptive Use and Breast Cancer Risk: Retrospective and Prospective Analyses From a BRCA1 and BRCA2 Mutation Carrier Cohort Study. JNCI Cancer Spectr. 2018 Jun 28;2(2):pky023. doi: 10.1093/jncics/pky023. eCollection 2018 Apr.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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