Why Does My Period Smell So Bad? Causes and Treatment

Lower half of a woman wearing fluxies period pants with period blood painted on her body


One of the many things that periods bring along with them every month, aside from period cramps or troublesome blood stains, is a funky smell. Anyone with a period will tell you that at some point or other, they've caught a whiff from down there, and it doesn't exactly smell like roses. Far from it. However, this is nothing to be embarrassed about. Keep reading to find out the causes of period discharge smells, and what to do if you’re worried that your period blood smells bad.

Why does my period smell and is it normal?

It's no secret that periods smell, but have you ever wondered why? Period blood contains three things: blood, uterine lining tissue and the unfertilised egg. It's usually normal for this combination to have a slight smell when it leaves the body. However, different smells can mean different things.

Common causes of period smell


The commonly described metallic or coppery smell comes from the presence of iron and blood in the discharge. This is perfectly normal and is nothing to worry about.

pH Level & Bacteria

Ordinarily, the pH of a vagina sits between 3.8-4.5, which is acidic. A pH of 7 is classed as neutral. The pH can be affected by the presence of urine, semen or blood, causing varying odours. Essentially, there are various types of healthy bacteria within your vagina; any disruption can cause infections or issues.

Christine Greves, a gynaecologist in Florida, reinforces this in her interview with Health, saying, “When you cut your finger, you wipe the blood off right away, and it’s fresh blood, meaning it hasn’t been sitting around for awhile…But period blood stays in the vagina for a longer period of time. It’s exposed to the bacteria in the vagina, and that’s where you get that odour.”

Body Odour

If you find yourself noticing a body odour-like smell during your period, this comes from your apocrine sweat glands. These are glands in your genital region that mix with bacteria on your skin, producing body odour. This could be caused by not practising good hygiene during your cycle. Fixing this can be as simple as regularly changing your protection methods, taking daily showers and making sure to only clean the outside of your vagina to protect the pH balance. The apocrine sweat glands are also activated by stress and anxiety, so it could be your body trying to tell you something.


Before the start of your period and during your cycle, you may start to notice a smell caused by hormonal changes affecting the bacteria/ acidity level. This can also shift during menopause. Some of the coppery/ metallic smell can linger after your period ends. However, you should not have vaginal odour long after your period. 

If you notice that your discharge is drastically different to normal, or lasts after your period ends, you should seek medical advice to be on the safe side.

Dietary Changes

Foods with a strong odour like fish or garlic can also cause changes to your vaginal odour. However, these changes are temporary; any long-term unpleasant odour could be a sign of an issue requiring medical attention.

Period discharge is usually not strong enough for other people to smell; if it is, it could be a sign of a problem. A bad odour during your period can have a variety of causes, depending on the description of the smell:

'Rotten’-smelling period blood, or blood that smells like rotten meat

Some people report a 'rotten' or ‘death’-like smell during their period. This smell is likely due to bacteria mixing with menstrual flow. 

A rotten smell during your period is often due to accidentally leaving a tampon or other foreign body in the vagina for too long. If you have left a tampon in for too long, you can try to remove it by finding the string and pulling it out. Otherwise, you will need medical help so a doctor can remove it. You can try to control this 'rotten' smell by changing your period protection frequently, especially during heavy-flow days and if you wear tampons.

You can find out more about causes of a heavier flow and how to reduce the side effects in our blog.

When your period blood smells 'fishy'

If you notice a "fishy" smell during menstruation, this might indicate a problem that you need to see a doctor for. Potential causes include:

Bacterial Vaginosis

Bacterial vaginosis often causes a fishy smell, which is a common infection that can cause periods to smell stronger than normal, as well as changes in discharge colour.

Bacterial vaginosis is caused by too much bacteria in the vagina, and your chances of getting BV can be increased by things like new or multiple sex partners and douching.

If you have BV, you will probably also have other symptoms before, during, and/or after your period, including:

  • Itchiness
  • Irritation
  • A burning sensation (especially during sex or when you pee)
  • Grey or white discharge when you're not on your period

Bacterial vaginosis is treated with antibiotics, and once this balances out the bacteria, you should no longer notice any unusual smells during your period.

If you have any of the above symptoms or feel like you might have bacterial vaginosis, make an appointment with your GP.


A fishy smell to your period or regular discharge could also be caused by Trichomoniasis. This is an STI caused by a parasite called TV (Trichomonas Vaginalis. Symptoms can appear within a month of infection; they include:

  • Discomfort or pain when having sex or urinating 
  • Swelling, itching and soreness around your vagina
  • Abnormal vaginal discharge, which could be thin, thick or frothy and a yellow-green colour
  • More discharge than normal, which may also have a fishy smell to it 

You should see a GP or go to your local sexual health clinic if you notice any symptoms like  these. 

When your period smells sweet

If you catch a sweet smell coming from your period blood, don't worry too much. This is common and is normally due to the acidic environment and bacteria in your vagina.

Why does my period smell like vinegar?

A sour, yeasty or tangy odour may be a sign that your vaginal flora’s pH is more acidic than normal. A short-term shift like this is not normally a cause for concern, as it is associated with the good bacteria in your vagina.

When other people can smell your period blood 

Periods are a natural part of life, and nearly every person with a period will tell you they've had a funky smell at some point or another - so don't feel embarrassed! Most of the time, although you may smell your period, it shouldn't be strong enough to smell through your clothes or pants, or for anyone else to pick up on. 

However, if you notice the smell is strong or if someone else does tell you they've noticed a smell, check in with your GP to make sure there's nothing serious going on. A strong, unpleasant odour could be a sign of a sexually-transmitted infection. More rarely, it could be a sign of vaginal or cervical cancer, or rectovaginal fistula, which is a condition where the opening between your vagina and rectum allows faeces to leak into your vagina.

Four women with varying body shapes and sizes stand together wearing fluxies underwear

My menstrual blood smells really bad, how can I fix it?

If you're worried about the smell of your period blood or think something more concerning might be going on, it never hurts to call your doctor to check for infections or other issues. 

In the event that there are infections present, you will be prescribed the relevant treatments to fix bad smells and other symptoms. Once you've eliminated the chances of any infection, there are many things that you can do to try and reduce the smell of your period blood. Here are a few tips: 

Change your period protection frequently

Depending on your flow, how often you need to change will be different, but you can experiment and see what works for you. 

If you wear tampons, make sure you don't leave them in too long — this will stop bacteria from building up, which will help keep smells to a minimum and also stop you from getting toxic shock syndrome.

Regular washing

Whilst daily showers will not help reduce smells caused by infections, they can help combat the usual odours associated with period blood and sweat. Making sure you keep on top of your hygiene by washing often, using a gentle bar soap around the area between your legs. The vagina itself is self cleaning, so washing the outside is more than enough. Avoid using perfumed soaps or body washes — the scents and chemicals may upset your vagina’s natural pH.

Wear breathable clothing

Go for breathable clothing and underwear that is moisture-wicking, allowing the area to breathe and stay cool. Switching from pads and tampons to our breathable period underwear will also give you longer-lasting protection, as they absorb your menstrual flow whilst keeping you dry all day long. 

You can learn more about whether period pants smell and their hygiene benefits in our helpful guide or shop the range here: Shop all period underwear.

Additional Period Smell FAQs

Why am I having a smelly discharge instead of my period?

A missed period and white discharge could be a sign of pregnancy or an infection. Late periods can also be induced by a number of lifestyle causes, including stress and weight loss. If you’re concerned about your vaginal discharge, you should always make an appointment with your GP or local sexual health clinic.

Does discharge smell before your first period?

Discharge does not have a distinctive smell in relation to your first ever period. It may vary due to hormonal changes, however any strong or foul new odours should always be checked by your GP. They may be an indication of an infection or issue causing a bacterial imbalance in your vagina.