There’s no single best birth control pill for everyone. The right one depends on your health history, your body’s response to hormones, and what you want the pill to do beyond preventing pregnancy. But understanding the two main categories and the factors that distinguish them will help you have a much more productive conversation with your provider, and recognize whether the pill you’re on is actually a good fit.
Combined Pills vs. Progestin-Only Pills
Every birth control pill falls into one of two categories: combined pills, which contain both estrogen and a progestin, or progestin-only pills (sometimes called mini-pills), which skip the estrogen entirely. This distinction matters more than brand names.
Combined pills work primarily by stopping ovulation. The progestin suppresses the hormonal signals your brain sends to your ovaries each month, preventing a mature egg from developing or being released. The estrogen component reinforces this effect and helps control breakthrough bleeding. Combined pills also thicken cervical mucus, making it harder for sperm to reach an egg.
Progestin-only pills work differently depending on which progestin they contain. Older formulations rely mainly on thickening cervical mucus rather than consistently stopping ovulation. Newer formulations containing drospirenone or desogestrel do suppress ovulation reliably, giving them stronger contraceptive effectiveness. If you’re considering a progestin-only pill, this difference is worth asking about.
With perfect use, fewer than 1 in 100 people will get pregnant in the first year on either type. With typical use, which accounts for missed pills and timing errors, about 9 in 100 will. That failure rate is the same for both categories, so the choice between them isn’t really about effectiveness.
Who Should Avoid Combined Pills
The estrogen in combined pills carries a small but real risk of blood clots, which is why certain people should use progestin-only pills instead. The CDC classifies combined pills as an unacceptable health risk for people aged 35 and older who smoke 15 or more cigarettes per day, due to increased risk of heart attack and stroke. The same applies to people who get migraines with aura, those with a history of blood clots, and people with certain heart conditions.
Progestin-only pills don’t carry the same clot risk, making them the go-to option for people who can’t take estrogen. They’re also commonly prescribed during breastfeeding. If none of these apply to you, both types are on the table.
Estrogen Dose and Breakthrough Bleeding
Most combined pills prescribed today contain between 20 and 35 micrograms of ethinyl estradiol, the synthetic estrogen used in the majority of formulations. The original pills from the 1960s contained 50 micrograms or more, so even “regular” dose pills today are already much lower than they used to be.
Lower estrogen doses (20 micrograms) tend to cause fewer estrogen-related side effects like bloating, breast tenderness, and nausea. The trade-off is a slightly higher chance of spotting or breakthrough bleeding, especially in the first few months. Pills with 30 to 35 micrograms generally do a better job controlling your cycle but may produce more noticeable side effects. For most people, the spotting with lower-dose pills decreases significantly by the fourth cycle, so it’s worth giving a new pill at least three months before deciding it isn’t working.
Choosing a Pill for Acne
If acne is a major concern, certain combined pills can genuinely help. Three specific formulations are FDA-approved for treating moderate to severe acne: one containing norgestimate with ethinyl estradiol, one with norethindrone and ethinyl estradiol, and one with drospirenone and ethinyl estradiol (the active ingredients in Yaz). The drospirenone version is approved for patients as young as 14, while the others are approved from age 15.
The reason these work is that estrogen increases a protein in your blood that binds up free testosterone, and certain progestins have anti-androgenic properties, meaning they counteract the hormones that drive oil production in your skin. Progestin-only pills don’t offer this benefit and may occasionally worsen acne, since they lack the estrogen component that helps lower androgen activity.
Pills for PMS and PMDD
If you experience severe premenstrual symptoms, particularly the mood-related kind classified as PMDD (premenstrual dysphoric disorder), a combined pill containing drospirenone with a low dose of ethinyl estradiol is the only oral contraceptive FDA-approved for PMDD treatment. Drospirenone has anti-mineralocorticoid activity, meaning it counteracts water retention, which helps with bloating and some mood symptoms.
The clinical evidence is real but modest. In one key trial, 48% of people taking the drospirenone pill met the criteria for symptom improvement, compared to 36% on placebo. That placebo response is notable: it means a significant portion of improvement may come simply from the regularity and predictability the pill provides. The FDA approval also notes that effectiveness beyond three cycles hasn’t been firmly established, so if this pill helps your PMDD initially but the benefit fades, that’s a recognized pattern worth discussing with your provider.
Managing Endometriosis or PCOS
For endometriosis-related pain, combined pills are often prescribed either on a standard 21-days-on, 7-days-off cycle or taken continuously without breaks. Continuous use skips the withdrawal bleed entirely and may be more effective at suppressing the hormonal fluctuations that trigger endometriosis pain, though the clinical evidence comparing these approaches is still limited.
For PCOS, combined pills serve a dual purpose: they regulate periods (reducing the risk of endometrial buildup from infrequent ovulation) and lower androgen levels, which helps with acne and excess hair growth. The specific formulation matters less than ensuring it contains estrogen plus a progestin that isn’t highly androgenic. Drospirenone and norgestimate are commonly chosen because they have lower androgenic activity.
Weight Gain and the Pill
A Cochrane review of 49 trials, covering 85 different weight-change comparisons, found no evidence supporting a causal link between combined oral contraceptives and weight gain. The four trials that included a placebo group showed no meaningful difference in weight between people taking the pill and those taking a sugar pill. People also didn’t quit the pill for weight-related reasons at higher rates than those on placebo.
This doesn’t mean your experience of feeling heavier on the pill is imaginary. Some pills cause mild water retention, especially in the first few months. But the large-scale data consistently shows that the pill doesn’t cause fat gain. If you’ve gained noticeable weight after starting a pill, other factors are more likely responsible.
Switching Between Pills
If your current pill isn’t working well, switching is straightforward. You can start a new pill immediately without waiting for your next period, as long as pregnancy has been ruled out. If it’s been more than five days since your last period started, use a backup method like condoms for the first seven days on the new pill. If you’re switching within the first five days of your cycle, no backup is needed.
Give any new pill at least two to three full cycles before judging it. Side effects like spotting, breast tenderness, and mood changes often resolve as your body adjusts. If they persist beyond three months, that’s useful information: it suggests this particular formulation isn’t a great match, and a different progestin type or estrogen dose may work better.
How to Narrow Down Your Options
Start with your health profile. If you smoke and are over 35, get migraines with aura, or have a clotting history, you need a progestin-only pill. If none of those apply, combined pills give you more options and better cycle control.
Next, think about what you want the pill to do beyond contraception. Acne and excess hair growth point toward a combined pill with an anti-androgenic progestin like drospirenone or norgestimate. Severe PMS or PMDD specifically points toward drospirenone with low-dose estrogen. Endometriosis pain may benefit from continuous dosing. If you just want reliable birth control with minimal side effects, a standard low-dose combined pill (20 to 30 micrograms of ethinyl estradiol) is a reasonable starting point.
Finally, consider your daily routine. Combined pills generally need to be taken at roughly the same time each day, but there’s some flexibility. Traditional progestin-only pills with norethindrone have an extremely narrow timing window, making them less forgiving if you’re not consistent. Newer progestin-only pills with drospirenone offer more flexibility and stronger ovulation suppression, making them a better choice if you want to avoid estrogen but don’t trust yourself to take a pill at the exact same time every day.