Side effects of the contraceptive pill: A complete guide
- Why the pill causes side effects
- Common short-term side effects and what most women experience in the first few months
- What side effects are specific to the combined pill?
- Long-term side effects
- Coming off the pill: What to expect and when to be concerned
- How to identify a red-flag symptom and when to contact a doctor
- Why the contraceptive pill causes side effects
- Common short-term side effects
- Side effects specific to the combined contraceptive pill
- Long-term side effects: What to expect
- Side effects of stopping the pill
- Coming off the pill: Understanding what’s a red flag
- When to contact a doctor
- Final thoughts
Why the contraceptive pill causes side effects
The contraceptive pill works by introducing synthetic hormones into the body, either a combination of oestrogen and progestogen (the combined pill) or progestogen alone (the mini-pill or progestogen-only pill). These hormones prevent pregnancy primarily by suppressing ovulation, thickening cervical mucus, and thinning the uterine lining.
Because these synthetic hormones interact with hormone receptors throughout the body, not only in the reproductive system, they can affect mood, skin, libido, digestion, and cardiovascular function. Most side effects reflect the body adjusting to a new hormonal environment, which is why they are often most pronounced in the first one to three months of use and settle thereafter for many women.
Good to know
Side effects vary considerably between individuals and between different pill formulations. If one pill causes persistent side effects, switching to a different formulation or type may resolve them. A prescriber can help identify the most suitable option for your circumstances.
Common short-term side effects
The following side effects are commonly reported in the first one to three months of starting the contraceptive pill. For most women, they improve significantly after the initial adjustment period.
| Side effect | Why it occurs | Typical duration |
|---|---|---|
| Nausea | Oestrogen stimulates the stomach lining | First 1 to 3 months; improves if taken with food |
| Breast tenderness | Hormonal changes affecting breast tissue | First few weeks; typically settles |
| Headaches | Hormonal fluctuations, particularly around the pill-free interval | First 1 to 3 months |
| Spotting or breakthrough bleeding | Uterine lining adjusting to hormonal changes | First 3 months; settles for most women |
| Mood changes | Progestogen can affect mood-regulating neurotransmitters | Variable; may persist in some women |
| Reduced libido | Reduced testosterone as a result of oestrogen-driven increases in sex hormone binding globulin | May persist with some formulations |
Important !
If nausea, headaches, or mood changes are severe or significantly affect your daily life, contact your prescriber. Persistent or worsening symptoms after three months are worth reviewing, as a different formulation may be better suited to you.
Side effects specific to the combined contraceptive pill
The combined pill contains both oestrogen and progestogen, and its side effect profile reflects both hormonal components. Some effects are specific to or more pronounced with oestrogen-containing formulations.
Cardiovascular risk: The combined pill is associated with a small increased risk of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism. NHS guidance notes that the risk of blood clots with the combined pill is very small but real, and is higher in women who smoke, are overweight, or have a personal or family history of blood clots. This risk is one of the main reasons the combined pill is not suitable for all women, and why a medical assessment before prescribing is essential.
Blood pressure: Oestrogen can cause a modest rise in blood pressure in some women. Blood pressure is typically monitored at the start of treatment and at follow-up appointments.
Migraine with aura: The combined pill is contraindicated in women who experience migraine with aura, due to an increased risk of stroke. Women with migraine without aura should discuss their individual risk with a prescriber.
Acne: Some combined pills, particularly those containing certain progestogens, can worsen acne, while others may improve it. The effect depends on the specific progestogen component and its androgenic activity.
Long-term side effects: What to expect
For most women, the combined pill is safe for long-term use. The evidence on long-term side effects is extensive, though it is important to distinguish between associations found in observational data and confirmed causal effects.
Cardiovascular risk: The small increased risk of VTE associated with the combined pill is most pronounced in the first year of use and in women with additional risk factors. The absolute risk remains low for most healthy, non-smoking women under 35.
Breast cancer: A large 2023 study published in PLOS Medicine, which followed over 9.5 million Danish women for nearly 11 years, found that hormonal contraceptive users had a slightly higher risk of breast cancer compared to never-users. The absolute excess risk was small, with approximately one additional breast cancer case per 7,690 women using hormonal contraception for one year.
Bone density: Some research has suggested that the pill may affect bone density in younger women, though the clinical significance of this is uncertain and any effect appears to reverse after stopping.
Cervical cancer: Long-term use of the pill is associated with a small increased risk of cervical cancer, though this risk appears to reduce after stopping and is closely linked to HPV infection.
Protective effects: It is worth noting that the combined pill is also associated with a reduced risk of ovarian and endometrial cancer, which provides a degree of long-term protective benefit.
Good to know
The long-term risks associated with the pill need to be understood in context. For most healthy women, the absolute risks are small and the benefits, including reliable contraception and reduction in period-related symptoms, outweigh them. A prescriber can help you weigh these considerations individually.
Side effects of stopping the pill
Coming off the contraceptive pill after extended use triggers a hormonal readjustment as the body restores its natural hormone production. This transition period can produce a range of temporary effects.
Irregular periods: After stopping the pill, it may take one to three months for the natural menstrual cycle to re-establish. Some women experience a delay of several months before regular periods return, particularly after long-term use. This is sometimes referred to as post-pill amenorrhoea and is usually temporary.
Acne: Women who were prescribed the pill partly to manage acne may notice a return or worsening of acne after stopping, as the pill's anti-androgenic effect is removed.
Mood changes: Some women report mood shifts, including low mood or increased anxiety, in the weeks following stopping the pill. This typically resolves as the body adjusts to natural hormone cycles.
Increased libido: Some women notice an improvement in libido after stopping, particularly if reduced libido was a side effect during use.
Fertility: Fertility typically returns quickly after stopping the pill, often within the first cycle. There is no evidence that long-term pill use impairs long-term fertility.
Important !
If periods have not returned within three months of stopping the pill, or if you experience significant or prolonged mood disturbance, contact your GP. While most post-pill effects are temporary, it is worth ruling out other causes.
Coming off the pill: Understanding what’s a red flag
The following summarises what is typically expected in the weeks and months after stopping, versus what warrants medical review.
| What is normal | What to discuss with a doctor |
|---|---|
| Irregular periods for 1 to 3 months | No period after 3 months |
| Mild acne or skin changes | Severe acne requiring treatment |
| Mild mood shifts in first few weeks | Persistent or severe depression or anxiety |
| Changes in libido | No improvement or significant ongoing sexual dysfunction |
| Temporary breast tenderness | A new breast lump or persistent pain |
| Light spotting between cycles | Heavy or prolonged bleeding |
When to contact a doctor
Contact your GP or prescriber promptly if you experience:
- A new, severe, or unusual headache while taking the combined pill
- Sudden visual disturbances or slurred speech
- Chest pain or shortness of breath
- Swelling, pain, or redness in one leg (possible DVT)
- Significant mood changes, low mood, or thoughts of self-harm
- A new breast lump
- No period for three months after stopping the pill
Seek emergency medical help (999 or A&E) if you develop sudden severe chest pain, difficulty breathing, or signs of a stroke including facial drooping, arm weakness, or speech difficulty.
Report any suspected side effects from your contraceptive pill to the MHRA via the Yellow Card scheme
Final thoughts
The contraceptive pill is a safe and effective option for most women, and the majority of side effects are mild, temporary, and manageable. Understanding what to expect, and knowing the difference between a normal adjustment and a symptom that needs attention, puts you in a better position to use it confidently.
FAQ
Do contraceptive pill side effects go away?
For most women, common side effects such as nausea, spotting, breast tenderness, and headaches improve significantly after the first one to three months as the body adjusts. Persistent side effects beyond three months are worth reviewing with a prescriber, as a different formulation may be more suitable.
How long do contraceptive pill side effects last?
Most short-term side effects settle within one to three months of starting. Side effects that persist beyond this period, or that significantly affect daily life, should be discussed with a prescriber.
Can the pill cause weight gain?
Weight gain is a commonly reported concern. The evidence is mixed: some women report weight changes, but large-scale clinical studies have not consistently demonstrated a direct causal link between hormonal contraception and significant weight gain.
What are the side effects of stopping the pill after a long time?
Coming off the pill after extended use can cause temporary irregular periods, acne, mood changes, and changes in libido as the body re-establishes its natural hormone cycle. Most of these effects resolve within one to three months.
Can the pill cause depression?
Mood changes, including low mood, are a recognised side effect of some hormonal contraceptives, particularly progestogen-dominant formulations. If you experience significant mood changes after starting the pill, discuss this with your prescriber. A different formulation may produce a more favourable mood profile.
Is it safe to take the pill long term?
For most healthy women, long-term use of the pill is considered safe. The risks associated with long-term use, including a small increase in breast cancer and VTE risk, are real but small in absolute terms and should be weighed against the benefits with a prescriber.
The DoktorABC medical advisory board
Dr. Roland Ruiken
Medical advisor, Norway
Dr. Viktor Simunovic
Medical advisor, Croatia