What’s the Best Way to Switch Birth Control Pills?

Every birth control pill comes with its own set of side-effects. Here's what to do when the cons outweigh the pros.

Since the first birth control pill was invented in 1960 as a means of "menstrual regulation," it's remained the most popular form of contraception in Canada. It's not a one-size-fits-all solution, though. There are a number of side effects that come along with the birth control pill. Some are positive, like acne control and regular periods. Others can be uncomfortable, like headaches, nausea, and breast tenderness.

In other words, a brand that works for your friend might not work for you. "There's not really a scientific way of determining which pill would be the right pill for the right person," says Dr. Ashley Waddington, the Co-Director of the Contraception Advice, Research, and Education fellowship at Queen's University in Kingston. "So, unfortunately for people, a little bit of trial and error can be required to figure out which one fits the best with their body."

This is what you need to know if you're thinking of switching birth control pill brands.

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What are the differences between the different pills?

There are two types of birth control pill: progestin (a synthetic form of progesterone) only and combined progestin and estrogen pills.

Most people who are prescribed the birth control pill are on the latter. The hormones in these pills prevent pregnancy by stopping ovulation, thickening the cervical mucus to prevent sperm from entering, and thinning the lining of the uterus so any fertilized eggs are less likely to attach. There are many brands on the market in Canada (some popular ones include Alesse, Lolo, and Marvelon). The difference between brands usually has to do with estrogen levels and the type of progestin used. "All combined pills contain the same type of estrogen [at different doses], and then there's variations in the type of progesterone they contain," says Waddington. "You may hear about high dose or low dose pills, and that refers to the estrogen levels."

Progestin-only pills don't contain any estrogen, which makes them safer for people who have cardiovascular diseases, high blood pressure, or are at a higher risk of forming blood clots. Progestin- only pills are also frequently prescribed to people who are postpartum and breast feeding. These pills don't stop you from ovulating, but it does thicken the mucus in the cervix which blocks sperm. Progesterone only pills also need to be taken at the exact same time every day to be effective, which makes them a bit harder to use correctly.

There are also monophasic pills (which deliver the same dosage of hormones every day and are more common) and triphasic pills (which deliver differing levels of hormones). Waddington notes monophasic pills are more consistent and may lead to fewer nuisance side effects like spotting and bleeding.

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Do low-dose birth control pills have other benefits?

Low dose pills (which, according to Waddington, contain about 10 micrograms of estrogen) might be beneficial for people going through perimenopause (the years-long life stage leading up to menopause). "As people approach menopause, they'll often experience irregular menstrual bleeding," says Waddington. "A birth control pill will override the whole hormonal system that leads to ovulation and menstruation and prevent dysregulated cycles that are common [during perimenopause]." Some perimenopausal people also experience symptoms like hot flashes and night sweats. A low, steady dose of estrogen from a birth control pill could improve these symptoms.

Once I'm on one brand, why would I switch?

Most people switch brands because they're experiencing intolerable side effects, which are thought of as being caused either by estrogen or by progesterone. "The ones we tend to blame on estrogen are things like nausea and headaches. Progesterone side effects are things like the sensation of bloating or breast tenderness," Waddington says.

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What are some common side effects when you start a new brand?

When you switch brands, you might start experiencing a whole new host of side effects. But, unless they're absolutely intolerable (for example, headaches that are so bad you can't function), Waddington strongly encourages people to give a new pill at least three months. "A lot of side effects that people get are going to be the most pronounced [during that time]" she says. "Things like headaches, nausea, nuisance bleeding or spotting, those tend to get better with time."

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Now that you've gotten your new prescription, how do you go about switching?

First things first, it's important to not take a break between brands. So, once you finish your week of placebo pills at the end of your original pack, start the new brand right away. "Then there should be ongoing coverage [from pregnancy]," says Dr. Waddington.

Of course, that's the ideal and sometimes it doesn't work out that way. If you do end up taking some time off between brands, use another form of birth control (like condoms) for at least two weeks.

And, of course, one big thing to remember with birth control pills: they don't protect against sexually transmitted infections. So, don't forget to use a barrier form of contraceptive to protect yourself from STIs.

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