Understanding What Are the Cons of the Combined Pill?

October 10, 2025 •

5 min read

Approximately 1 in 1,000 people using the combined contraceptive pill will develop a blood clot, a risk that a doctor will assess before prescribing. Understanding what are the cons of the combined pill, from minor but bothersome side effects to more serious health risks, is crucial for anyone considering this method of birth control.

Quick Summary

The combined oral contraceptive, while highly effective, has drawbacks including common side effects like nausea and headaches, serious risks such as blood clots, and the necessity of strict daily compliance. It also offers no protection against sexually transmitted infections (STIs).

Key Points

Common side effects are temporary: Many new users experience mild side effects like nausea, headaches, and breast tenderness, but these often disappear within a few months as the body adjusts.
Serious risks include blood clots: A small, but significant, risk of developing serious conditions like deep vein thrombosis (DVT), pulmonary embolism, stroke, and heart attack exists, particularly for smokers over 35.
Daily adherence is crucial: The combined pill requires daily dosing, and its effectiveness significantly drops if pills are missed or taken late.
No STI protection: This contraceptive method does not prevent sexually transmitted infections, requiring the use of condoms for protection.
Contraindicated for certain conditions: People with a history of blood clots, certain migraines, or specific cancers are advised against using the combined pill due to elevated risk.
Requires a prescription: The need for regular check-ups and prescriptions can be inconvenient and an access barrier for some individuals.
Hormonal impact: The presence of estrogen and progestin can cause mood changes and impact milk supply in breastfeeding mothers.

While the combined oral contraceptive pill is a popular and effective method of preventing pregnancy, it is not without its disadvantages. Potential users should be aware of both the common side effects and the less frequent, but more serious, health risks associated with its use. Open discussion with a healthcare provider about these drawbacks is essential to ensure it is the right fit for your health and lifestyle.

Common Side Effects

Many people experience minor, temporary side effects when they first begin taking the combined pill, which often resolve within a few months as the body adjusts to the hormonal changes. The most frequently reported issues include:

Irregular bleeding: Spotting or breakthrough bleeding between periods is especially common during the initial months of use. This is more likely with lower-dose pills or continuous dosing regimens.
Nausea: A feeling of sickness can occur, especially when first starting the pill. Taking the pill with food or at bedtime can help alleviate this.
Breast tenderness: Changes in hormone levels can cause breasts to feel sore or tender.
Headaches: Some people experience an increase in the frequency or severity of headaches or migraines. For those with migraines with aura, this method may not be suitable.
Mood changes: Hormonal fluctuations can impact mood and emotions, with some people reporting irritability or depression.
Bloating: Fluid retention can lead to a feeling of being bloated.
Decreased libido: A change in sex drive is another possible side effect linked to hormonal shifts.
Vaginal discharge: Changes in the consistency or amount of vaginal discharge can occur.

Factors Affecting Common Side Effects

Several factors can influence the type and severity of side effects experienced. These include:

The specific combination of estrogen and progestin in the pill.
The dosage of the hormones.
Individual sensitivity and pre-existing hormonal conditions.
The duration of use; many side effects subside with time.

Serious Health Risks

Although rare, the combined pill carries an increased risk of serious cardiovascular complications, particularly for certain individuals. A healthcare provider will evaluate these risks based on your medical history.

Blood clots (Venous Thromboembolism - VTE): The most significant risk is the formation of blood clots in the legs (deep vein thrombosis) or lungs (pulmonary embolism). This risk is higher for those who smoke, are over 35, have a family history of blood clots, or have certain genetic clotting disorders. Some progestins, like drospirenone, may carry a slightly higher risk than others.
Heart Attack and Stroke: The combined pill is associated with a small increase in the risk of heart attack and stroke, especially in women over 35 who smoke.
High Blood Pressure: The pill can cause a slight increase in blood pressure in some users, which requires monitoring.
Cancer Risks: While the combined pill can lower the risk of certain cancers (ovarian and endometrial), it may slightly increase the risk of breast and cervical cancer while in use. However, these risks typically decrease after discontinuing the pill.

Required Daily Adherence

For the combined pill to be effective, it must be taken daily, ideally at the same time each day. This daily requirement can be a significant drawback for many people, and a missed pill can dramatically increase the risk of an unintended pregnancy. Factors that can decrease the pill's efficacy include:

Missing one or more doses.
Vomiting or experiencing severe diarrhea within a few hours of taking a pill.
Taking certain medications, such as some antibiotics and anticonvulsants.
Taking herbal remedies like St. John's wort.

No Protection Against STIs

A major drawback of the combined pill is that it does not offer any protection against sexually transmitted infections (STIs). Users who are not in a mutually monogamous relationship and are at risk for STIs must use a barrier method, such as a condom, in addition to the pill.

Inconvenience and Access

Beyond the medical aspects, the combined pill presents practical inconveniences:

Requires a prescription: In most countries, the pill is not available over the counter, requiring regular doctor visits for a prescription and monitoring.
Initial adjustment period: As mentioned, the first few months can involve temporary side effects that can be uncomfortable or disrupt daily life.
No STI protection: The necessity of using a second method of contraception (condoms) for STI prevention adds an extra step for many users.

Combined vs. Progestin-Only Pill: Potential Downsides

When exploring birth control options, understanding the differences in side effects and risks can be helpful. While both have cons, they are distinct.


Feature	Combined Pill	Progestin-Only Pill (Minipill)
Adherence	Must be taken daily, ideally same time. Missing a pill has higher risk.	Must be taken at the exact same time every day. Taking it a few hours late reduces efficacy.
Hormones	Estrogen and Progestin	Progestin only
Blood Clot Risk	Small, increased risk (VTE) for certain individuals, especially with specific progestins and risk factors.	Generally no increased risk of blood clots due to lack of estrogen.
Milk Supply	Estrogen can decrease milk supply, not recommended in early breastfeeding.	Safe for breastfeeding and does not impact milk supply.
Health Conditions	Contraindicated for people with certain conditions (e.g., migraines with aura, history of blood clots).	Can be a safe option for many people who cannot take estrogen.
Menstrual Bleeding	Can regulate, lighten, or stop periods. Breakthrough bleeding common initially.	Can cause irregular menstrual bleeding, spotting, or no periods at all.

Conclusion

While the combined oral contraceptive is a powerful tool for pregnancy prevention with many associated benefits, it is crucial to recognize its downsides. The cons of the combined pill range from mild, manageable side effects to rare but serious health risks like blood clots and cardiovascular events. The daily adherence requirement and lack of STI protection are additional factors to consider when choosing this method. An informed decision can only be made after a comprehensive discussion with a healthcare provider, considering your personal health history, lifestyle, and individual risk factors. For more information and resources on contraceptive methods, you can visit the American College of Obstetricians and Gynecologists (ACOG) website.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Please consult with a healthcare professional to discuss your individual health needs and appropriate contraception options.

Frequently Asked Questions

There is a common misconception that the combined pill causes significant weight gain, but studies have not confirmed this. Any temporary increase in weight is more likely due to fluid retention and usually resolves.

While the combined pill is associated with a slight increase in the risk of breast and cervical cancer during use, it also provides significant protection against ovarian and endometrial cancers. The overall risk assessment is complex and should be discussed with a doctor.

The course of action depends on when you miss a pill. Generally, if you miss one pill, you should take it as soon as you remember. If more pills are missed, follow the specific instructions in the pill pack and use a backup contraception method, like condoms, for at least seven days.

If you experience migraines with aura (visual or sensory disturbances before the headache), the combined pill is generally not recommended due to an increased risk of stroke. For migraines without aura, the pill may be suitable, but a doctor's consultation is necessary.

Smoking dramatically increases the risk of serious cardiovascular events, like blood clots, heart attack, and stroke, for those taking the combined pill. This risk is particularly high for women over 35 who smoke, and the pill is contraindicated in this demographic.

No, the combined pill does not offer any protection against STIs. The use of condoms is necessary to prevent the transmission of infections during sexual activity.

Common early side effects include breakthrough bleeding, nausea, breast tenderness, and headaches. These are typically temporary as your body adjusts to the hormones and usually improve within two to three months.