Yes, birth control can affect your mood or weight – but for most people, any change is mild, temporary, or doesn’t happen at all. If you do notice mood changes, low mood, or unexpected weight gain after starting contraception, we can talk it through with you and help you find an option that feels right for your body and your life.
Below, we’ll explain what’s known about common birth control side effects (including mood changes and weight changes) and what you can do if you’re worried.
Why some people notice changes (and others don’t)
Hormonal contraception works by changing hormone levels in your body. Because hormones can influence things like appetite, fluid retention, sleep, and stress response, it’s possible to notice changes – especially in the first few months.
But it’s also common for similar changes to be caused by other factors, such as:
- stress, life changes, or poor sleep
- changes in diet, exercise, or routine
- natural weight changes over time
- underlying health conditions (including mental health conditions)
That’s why we focus on what’s happening for you, not just what “usually” happens.
Mood changes: what we know
Some people report mood changes after starting hormonal contraception – for example feeling more irritable, emotional, flat, anxious, or “not quite themselves”. Others Most notice no change, and some people report feeling better.
A large study discussed by the MGH Center for Women’s Mental Health (the Harvard Study of Moods and Cycles) found that most people reported no mood change on the oral contraceptive pill:
The same article notes that among people with a history of depression, most still reported no change or improvement, while a smaller proportion reported worsening mood (Nonacs, 2015).
What that means in real life: mood changes can happen, but they aren’t inevitable – and if they do happen, it’s reasonable to review whether your method is the right fit for you.
Weight changes: what we know
Weight can change for many reasons, which makes it hard to pin changes on contraception alone. Some people notice changes in:
- appetite
- fluid retention or bloating
- routine (exercise, sleep, stress) after starting a new method
Overall, summaries from sources like Healthline and WebMD describe that most hormonal birth control methods aren’t strongly linked to large, consistent weight gain for most people, though individual experiences can vary. They also note that the contraceptive injection (the “shot”) is the method most commonly associated with weight gain in research and clinical discussion. (Healthline, n.d.; WebMD, n.d.)
What about “progesterone pill weight”?
People often use “progesterone pill” to mean the progestogen-only pill (sometimes called the mini pill). If you’re worried about progesterone pill weight changes, it may help to know that:
- Some people notice small changes, don’t notice any
- Changes may be related to appetite or fluid retention rather than body fat
- If weight changes feel sudden or distressing, it’s worth checking in so you can look at alternatives
Why side effects vary so much
Even when people use the “same” category of contraception, their experience can be different. Side effects can vary based on:
- The type of hormone (and the dose)
- Whether the method is taken daily or is long-acting
- Your health history (including previous mood symptoms)
- What else is going on in your life at the time (stress, sleep, workload, relationships)
This is why it’s completely reasonable to reassess – especially if you’ve recently started or switched methods.
When to check in with a clinician
Please reach out for support if:
- Mood changes start after starting contraception and don’t settle
- You feel persistently low, anxious, or emotionally “not yourself”
- You’ve had depression or anxiety before, and symptoms return
- Weight changes feel rapid, distressing, or hard to explain
- You want to change methods (you don’t need to wait)
If you feel unsafe or you’re having thoughts of self-harm, seek urgent help straight away: call 000 in an emergency, or Lifeline on 13 11 14.
Choosing contraception if mood or weight is a concern
At MSI Australia, you can explore contraception support here:
- Contraception services: https://www.msiaustralia.org.au/contraception-services/
- Long-acting reversible contraception (LARC): https://www.msiaustralia.org.au/contraception-services/larc/
LARC options can suit people who want reliable contraception without remembering something daily. If you’d rather avoid hormones altogether, a clinician can also discuss non-hormonal options and whether they’re appropriate for you.
Emergency contraception
If you’ve had unprotected sex or a contraception failure, emergency contraception may be an option. Because timing matters, it’s worth checking your options as soon as you can:
- Emergency contraception: https://www.msiaustralia.org.au/emergency-contraception/
If you’re experiencing mood changes or weight changes after starting birth control, you don’t have to manage it on your own. We can help you talk through birth control side effects, compare contraception options, and choose what suits you.
