Mini Pill Side Effects
The mini pill refers to a range of contraceptive pills known as progesterone-only pills (POP). These pills contain progesterone only, and no oestrogen, compared to the combined pill, which contains both progesterone and oestrogen synthetic hormones, it has less side effects.
The mini pill can be a great alternative contraception choice for women who find it difficult to tolerate medications containing oestrogen, or who are not suitable for oestrogen based contraceptives. This includes women who are over 35 years of age, women who smoke and women who are breastfeeding.
The mini pill works as a contraceptive method by:
- Creating a mucus barrier at the cervix that makes it difficult for sperm to pass through
- Changing and thinning the lining of your uterus so it's less likely that a fertilised egg can implant
- Stopping ovulation in some cases (approximately 60% of women)
It's estimated that around 6% of women in the UK between the ages of 16 and 49 take the mini pill.
Common Side Effects
While the mini pill has fewer side effects than the combined pill, it is still possible to experience some. The most common side effects associated with taking progesterone only pills are:
- Irregular menstrual periods
- Breast pain or tenderness
- Acne and other skin changes
- Increased hair growth
- Generally, out of 10 women taking the mini pill:
- Four will have regular monthly bleeding and see no change
- Four will have irregular monthly bleeding
- Two will become amenorrhoeic which is the absence of a monthly period
Rare side effects and risks
Combined contraceptive pills, containing oestrogen and progesterone, have been found to slightly increase your risk of getting breast cancer, endometrial cancer, and liver tumours. It is not known whether the mini pill could also increase the risks of these conditions, but it is thought that if they do, it is probably to a lesser extent that the combined pill.
It has been found that some women can develop small cysts on their ovaries. These generally don't require treatment and disappear without treatment. Quite often there will be no symptoms, but some women will experience pelvic pain.
If you do become pregnant while taking the mini pill, there is an increased risk that the pregnancy will be an ectopic pregnancy. There was some research into whether the mini pill could cause weight gain, loss of bone density, or mood changes but no conclusive evidence has been found.
How to prevent the risk of side effects
To minimise the risk of side effects, you should disclose all relevant information to your doctor during your initial consultation.
1) Advise you doctor of allergies
It is possible to have an allergy to one of the ingredients contained in the mini pill. You should advise your doctor in particular if you are allergic to aspirin, a yellow food colouring called tartrazine, progestins or any other medications.
2) Advise your doctor of all medications your taking
The mini pill can interact with other medications that can impact on its effectiveness and also potentially increase your risk of side effects. You should advise your doctor of all prescription medications and non-prescription medications you are taking during your consultation. You should also mention any vitamins, nutritional supplements and herbal products such as St John's Wort.
In particular, you need to make sure to advise them if you are taking Rifadin (rigampin), Dilantin (phenytoin), Tegretol (carbamazepine), Luminal or Solfotom (phenobarbital), as these can all interact with progesterone only pills.
3) Advise your doctor of previous medical history
Because of the potential for the mini pill to increase your risk of breast cancer and liver disease, it's important to advise your doctor if:
- You've had undiagnosed breast lumps
- You've had breast cancer
- You've had liver tumours or liver disease
- You have diabetes
- You've had a stroke or have coronary heart disease
One of the common side effects with the mini pill is irregular menstrual bleeding. It is important to let your doctor know if you've experienced problems with heavy bleeding, irregular bleeding or have had vaginal bleeding between periods in the past.
4) Advise your doctor if you are or could be pregnant
It is not advised to take progesterone only contraceptives while pregnant. If you think you could be pregnant, you should advise your doctor. If you become pregnant while taking the mini pill, you should stop taking it and speak with your doctor, as it can put you at an increased risk of an ectopic pregnancy.
Dealing with the mini pill side effects
The common side effects are usually mild and should ease with time, but some can be serious. If you experience any severe side effects or persistent symptoms you should seek medical advice. In particular, you should speak to your doctor if you're:
- Experiencing prolonged bleeding
- Amenorrhoeic and your periods are absent
- Experiencing severe abdominal pain
If you think that the mini pill may be the right contraceptive choice for you, you can complete an online consultation form here.