Contraception and heavy periods

Heavy periods are when you need to change your pad, tampon or menstrual cup more than every 2 hours, or if you pass blood clots in your period. If you need to change your pad, tampon or menstrual cup during the night then you also have heavy menstrual bleeding.

Other signs of a heavy period include:

  • needing to use 2 types of sanitary products at the same time

  • bleeding through to your clothes or bedding

  • you avoid things you’d usually do, like exercise, or take time off work because of your period

On average, we lose 2–3 tablespoons of blood during a period. And most periods last around 4–5 days. People with heavy menstrual bleeding may lose twice that amount of blood, and their periods can last more than 7 days.

Some people have heavier periods than others and we don’t know why. The causes of heavy bleeding are often unknown.

But there are some causes that can be identified and treated:

  • often periods can get heavier when you first start your period, after pregnancy or during menopause

  • it could be caused by a medical condition that affects the reproductive system, such as fibroids, endometriosis or polycystic ovary syndrome (PCOS)

  • stress and depression can affect your period

  • some medicines and treatments can make your periods heavier

  • some contraceptive methods such as the non-hormonal coil can cause heavy bleeding

How heavy bleeding can affect you

Heavy menstrual bleeding can be a problem when it stops you from doing your normal activities or makes you anaemic.

Anaemia is a condition when you don’t have enough haemoglobin in your blood to carry oxygen from the lungs to the tissues of your body where it's needed. If you lose very large amounts of blood during your period, then your body can’t make new haemoglobin fast enough, and this causes anaemia.

Anaemia causes tiredness, weakness and shortness of breath.

When to see a doctor about heavy bleeding

You should talk to your doctor if:

  • you have regular periods that become heavier

  • you have always had heavy periods 

If you get unpredictable bleeding that is sometimes or suddenly heavy, bleeding when you don’t expect it, or any kind of unusual bleeding you should also speak to your GP or local sexual health clinic.

This can be caused by: 

  • STIs (sexually transmitted infections)

  • cervical cancer

  • cancer of the lining of the womb (uterus)

  • complications of pregnancy, such as a miscarriage

 If you have any unusual bleeding,  it’s usually recommended that you:

  •  do an STI test to rule out infection

  • take a pregnancy test to rule out pregnancy

  • if you’re 25 or older, make sure you’re up to date with your cervical screening (smear tests)

Read more about irregular bleeding.

Using contraception to help with heavy bleeding

Some methods of contraception can reduce heavy menstrual bleeding and be used safely as a long-term treatment. 

The non-hormonal is not recommended as it can make heavy periods worse.

The pill, the ring and the patch

Some methods stop ovulation and thin the lining of the uterus. This means that the bleeding you have every 3 weeks is not a normal period and there’s much less blood to lose. These methods include: 

You can keep using these methods without taking a break so you only bleed every three months, or even use them continuously and not have any bleed break at all.

These methods will also help with any other symptoms you get as part of your period, like premenstrual tension (PMT), pain, cramping and mood changes. 

“I ended up going on hormonal birth control. I couldn’t deal with the heavy bleeding and cramps that made me want to vomit for the whole week I was on. I know it’s not good for everyone, but I’d recommend trying to find a hormonal contraception that works for you if you have period hell.”

The hormonal coil

The hormonal coil is very effective at controlling heavy periods. The 52mg levonorgestrel intrauterine system (known as Mirena or Kyleena) is extremely effective at reducing bleeding. It can cause irregular bleeding in the first 6 months but this is usually lighter and improves over time. Most people have no periods at all by the end of the first year.

The progestogen only pill, the implant and the injection 

The progestogen pill, the implant, and the injectable contraceptive may reduce blood loss. But they can affect your bleeding in different ways, and it's hard to predict the exact effect they'll have.

They may make the amount of blood loss better or worse, and are likely to change the number of days that you bleed - so you'll bleed for more or fewer days each month.

Irregular bleeding and spotting is a very common side effect of progestogen only contraception. Some people find their periods completely stop, others may get irregular bleeding which is manageable, some may get regular periods or others may get continuous bleeding which means they decide to change methods. 

You cannot predict how your bleeding pattern will be on this type of contraception, so you need to try it to see how your body responds to it. 

It can take around 3 months for your body to get used to a new method of contraception and for side effects to settle, so it’s best to try a new method for 3 months before reviewing how it works for you.

Reviewed by Helen Burkitt. Senior Sexual Health and Contraception Nurse
Last updated at: 22 February 2024
Published on: 29 November 2022