If you’re buying contraceptive pills yourself for the first time, you might be wondering why there are so many available.

The simple answer is that every user is different, and no one type of contraceptive pill is suitable for absolutely everyone.

Some are more sensitive to hormones than others, and therefore more likely to experience side effects; while others may be less sensitive and require a slightly higher dose; and others may even be seeking a treatment which provides contraception as well as alleviating other symptoms, such as acne or period pain.

And because there are so many different types of pill available, it is absolutely possible that the first one you try isn’t the ideal one for you.

It may also be the case that a pill becomes less suitable as your body changes, and you may find that an alternative works better.

So how do you determine which birth control pill is the best one for you? Below is our comprehensive guide to the different products available, and the situations in which they might be employed:

The combined pill

Undoubtedly the most commonly prescribed option, this term is wide-ranging and is used to refer to any pill which contains a combination of two hormones.

In all cases, these hormones will be synthetic versions of progesterone and oestrogen, two naturally-occurring agents which play a vital role in ovulation and the menstrual cycle.

The combined pill has been around since the 1960s, and may be issued to someone who is taking birth control for the first time and is otherwise healthy.

There are, however, several different types of combined pill.

21 and 28-day

The 21-day pill is so called because the user takes it for three weeks out of every four, usually starting on the first day of their period. After 21 days of continuous once daily application, the user will have seven pill-free days, before recommencing their application window.

Examples of 21-day pills include BiNovum, Levest and Lizinna.

Those using the 28-day pill will take it every day (the letters ‘ED’ after the product name will indicate it as such). In such cases, a one-month pack will contain 21 active pills and seven inactive pills.

These inactive pills will not perform any additional function in the body; but they may aid the user’s administration, in that no one-week break is required. This then makes it easier for the user to remember to take their pill.

Logynon and Microgynon are examples of pills which are offered as both 21-day and everyday courses.

Monophasic and Multiphasic

Combined pills may also differ in their periodic stages of function, and be mono- or multiphasic.

For instance, a monophasic pill is one in which all 21 pills contain the same level of hormones.

Over the three-week application period, they will provide a constant hormonal dose to the user, which only changes when the seven-day rest period commences. During this time, the user will often have a withdrawal bleed which resembles a period.

Brevinor and Cilest are popular types of monophasic pills, and are often issued by doctors to those using the pill for the first time.

In a cycle of biphasic pills such as BiNovum or Synphase, the levels of hormones distributed will change once.

For example, BiNovum is a 21-day course, which contains seven pills with 0.5mg of norethisterone (a synthetic progestogen) and 14 pills with 1mg of norethisterone; thereby increasing the dose of one hormone after one week.

These types of pills were developed to offer an alternative to monophasic pills, which can cause side effects in some. However, a review into available studies by the Cochrane Collaboration has found that, in terms of both efficacy and incidence of side effects, there is little to separate the two.

Triphasic pills employ what experts term a 7/7/7 approach, whereby a 28-day cycle will contain three different doses of pills which change approximately each week, followed by the usual seven-day rest period.

They were engineered with the intention of closely simulating the natural fluctuations of hormones during the menstrual cycle, therefore limiting hormonal disruption and reducing the likelihood of breakthrough bleeding.

A doctor may issue a triphasic pill such as TriNovum or Logynon if a monophasic pill has caused side effects; but it should be noted that due to their staged method of administration, it can be difficult to recover a programme of use in the case that a pill is missed.

An example of a quadriphasic pill is Qlaira, and a one-month cycle contains four different levels of hormone, with 26 active and only two inactive pills.

Once more, this type of pill may be employed to alleviate inter-periodic bleeding, but studies have been able to determine little difference between this type and monophasic in terms of efficacy and side effects.

Low dose or standard dose

For some users, the standard dose of a particular pill may have unwanted side effects (such as headaches, sickness or breast pain), or pose an increased risk of causing them.

In such cases, a lower-dose contraceptive pill may be prescribed by a doctor, and this will contain a lower amount of the contingent hormones.

Loestrin is one pill which is offered as a standard and reduced dose (30 and 20, respectively, with these figures referring to the microgram count of ethinylestradiol).

Another example is Mercilon, which contains the same ingredients as Marvelon but at a decreased dose.

Standard dose pills may be preferred however, by those who want to use their contraceptive to combat symptoms such as acne.

Available data is somewhat inconsistent, with studies conducted seeming to suggest that the different effects on acne across different pill dosages are less than significant; but some women do find that stronger doses can reduce spots, and even lighten bleeding.

Pills that provide contraception as a secondary function

Furthermore, there are certain pills which contain the same active ingredients as the combined pill (namely a version of progesterone and a version of oestrogen) but which aren’t used primarily as contraceptives.

One notable example is Dianette.

This pill was formerly used as a contraceptive option, but due to a perceived higher risk of posing side effects, is now prescribed mostly to treat acne which has not responded to other medicines, such as antibiotics. It has also been used in some cases to alleviate excess hair growth in women.

Its contraceptive qualities however, make it an effective means of birth control when applied in these cases; while it should not be used solely for contraception, it invariably acts as a contraceptive in those instances where it is issued.

Medicines like Dianette should obviously not be used in addition to other hormonal contraceptive pills or devices, as doing so can prove harmful.

The mini pill

Known also as the progesterone-only pill, or POP, the mini pill differs from the combined version in that it only contains one hormone; an artificial formulation of progesterone.

It was first developed in the 1970s, and can function as an effective yet lower-risk alternative to combined pills.

Today, the mini pill is (amongst others) available as Cerazette, Micronor and Aizea.

When used correctly, some mini pills have shown to be more than 99 percent effective; which is comparable to (and in most cases equivalent to) the success rate of combined birth control methods.

So who is the mini pill for?

Due to the fact that the progesterone-only pill contains no oestrogen, it is used in those instances where a sensitivity or biological preclusion to this hormone is present.

For example, someone with high blood pressure or a history of blood clots, or who is overweight, may be unable to use medication containing oestrogen, and the mini pill may provide a safer alternative.

Prescribers may also be more likely to issue the POP to women who are over the age of 35 and smoke.

Similarly, because the progesterone-only pill contains no oestrogen, it is less likely to interfere with the flow of milk during breastfeeding; and mini pills can occasionally therefore be prescribed in such situations, to provide contraceptive cover in new mothers.

There are, however, some drawbacks to using the mini pill. It cannot be taken alongside some other treatments, such as antibiotics, and be rendered less effective by such.

The window of application may also be smaller than that of combined pills: for instance, it may be necessary to take it within the same three-hour window each day.

Breakthrough bleeding or spotting may also be more frequent with the POP, as might irregular periods.

With this being said, these disadvantages are negligible, especially for someone who is not as able to tolerate oestrogen; and the mini pill offers a viable yet lower-risk alternative to the regular pill for many.

Does it make a difference if I take generic or branded pills?

It shouldn’t.

As with other types of medications, generic contraceptive pills are subject to the same manufacturing standards and conditions as their branded counterpart.

The American Congress of Obstetricians and Gynecologists considers the two clinically equivalent.

However, some women have reportedly noticed differences between the branded and generic versions of birth control pills in terms of side effects; although these differences have not thought to extend to rates of efficacy.

Your doctor has a duty to consult and inform you before switching your medication. If you’re concerned about your current course of contraceptive pill or possible side effects, you should speak to your GP or family planning nurse.

What happens if I want to switch pills?

As mentioned above, it might be the case that if you experience side effects when using one particular type of pill, your doctor decides to issue a different kind.

Your doctor will usually issue instructions on what to do when switching pills. They may suggest that you make the switch immediately, or that you begin taking your new pill the following month, after your current strip has finished.

It is important to note that when changing pills, it is possible for your contraceptive cover to temporarily lapse for a few days, while the ingredients of the new pill take effect. Therefore, it is important to observe any extra contraceptive measures during this time, such as using a condom, to cover the gap.