Why does my vagina smell? What's normal and what's not

Author: Veronica Danger
Qualified Naturopath | BHSc(N)

Last reviewed: July 20, 2026

A vagina has its own natural smell, and that is completely normal. It should not smell like your soap, perfume, fruit or flowers. Most day-to-day changes in odour are harmless and shift a little across your menstrual cycle². The smells worth paying attention to are the strong fishy, foul or rotten ones, which usually mean the balance of bacteria in your vaginal microbiome has tipped and the vaginal pH has risen, not that you have done anything wrong.

There isn’t much research on vaginal odour, despite it being one of the most common reasons¹ for a doctor’s visit. You are likely already familiar with your own normal scent, even though it varies across the month.

There are times when things smell a bit off, or downright grim. You are not alone if you have asked the internet, why does my vagina smell like onion? or even why does my vagina smell like death?

Here, we look at vaginal odours³, from the fresh to the foul, and explain the vaginal infections, environmental factors and hormonal shifts they are linked to. These include:

Bacterial vaginosis (BV)
Aerobic vaginitis (AV)
Trichomoniasis
Yeast infection and candida
Sweating¹
Menstruation (periods)⁴
Ovulation⁵
Sex-related odour
Diet and lifestyle⁶

How to accurately check vaginal odour – the sniff test

This is the home-grown My Vagina version, not to be confused with the whiff test. It is generally effective at checking your own vaginal odour if you can reach your vagina and have a normal sense of smell.

The sniff test is best done after a shower, to avoid picking up regular odours from your groin or vulva, but can be done anytime you are relatively clean.

First, wash your hands in warm water, but don’t use any scented soap – you want your hands to be completely smell-free. Any fragrance in soap, perfume or moisturiser will interfere with your nose doing this odour-detecting job.

Gently spread your labia and insert one finger – whichever is easiest – into your vagina, give it a wiggle to make sure it’s coated in your vaginal fluids, and then sniff your finger.

Easy. The sniff test can be done anytime you need a clear reading on what your vaginal fluids smell like. You can also use it on your vulva, in the crevices, to see what’s normal there.

Check after a shower, then at the end of your day, and see the difference.

Where does vaginal odour come from?

The origin of vaginal odour is complex and likely varies from person to person. Several factors are in play at once.

In simple terms, vaginal odour is a combination of scents produced by the byproducts of different microbes⁷ within the vaginal microbiome and their interactions with your vaginal secretions.

If you want to know which bacteria and fungi are in your vagina, get a comprehensive vaginal microbiome test (order online, anywhere in the world).

All body odour originates from the different smells bacteria produce, known as bacterial odorants⁸.

Certain vaginal bacteria release smelly chemicals, specifically ones called ‘biogenic amines’. These biogenic amines⁹ can raise the vaginal pH.

Currently, Dialister, Prevotella, Parvimonas, Megasphaera, Peptostreptococcus, and Veillonella are suspected of producing most of the pungent molecules¹⁰ because they carry the genes needed to make biogenic amines.

Certain biogenic amines (putrescine, cadaverine) are produced by the microbes that cause BV and smell like rotting meat or fish – hence the fishy odour associated with BV.

Biogenic amines aren’t the sole cause of vaginal odour, though. Odour also happens when vaginal bacteria mix with other fluids or bacteria nearby.

Factor in discharge, the microbes in genital sweat, menstrual blood, a dash of urine, and occasionally trace amounts of faeces, and you have a full picture of what makes up vaginal odour.

For example, the microbes in digestive gas produce hydrogen sulphide⁷, a bacterial odorant that smells sulphurous, like rotten egg. Vaginally, this odour is linked to certain bacteria and conditions.

Types of vaginal odours and what they can mean

Earthy, ripe, or musky vaginal odour

Although there is no single smell for a healthy vagina, vaginal odour may be described as a bit musty, pungent or ‘of the sea’.

A stronger version of your vagina’s usual odour is typically not a problem. The types of bacteria and their numbers fluctuate with hormones across the menstrual cycle, which can shift vaginal odour and pH.

At the end of menstrual bleeding, or after being sweaty or having a long day, odour might be a little stronger.

BO vaginal odour

The vulva has two types of sweat gland, eccrine and apocrine. Eccrine glands produce odourless moisture; apocrine glands produce oily secretions that interact with skin bacteria to create smells.

Apocrine glands are found largely on hair-bearing skin, including the pubic area. So when you sweat, the crotch area can smell like BO. By the end of the day, the vulva won’t be as fresh.

Onion-like vaginal odour

If you have a distinctly oniony vaginal or groin odour, you may be dealing with a metabolic issue with sulphur, which may benefit from the careful eye of an experienced practitioner. Your vaginal microbiome may be looking great, and you may have no other symptoms.

If this is you, we strongly recommend you book in with one of My Vagina’s qualified, experienced vulvovaginal specialist practitioners. You may not have a vagina problem, but an issue processing sulphur compounds from food and regular body metabolism, and it is showing up as oniony odour.

Rotten vaginal odour (or similar to eggs)

Let’s be honest; many of us have been here. While unpleasant, this odour isn’t a cause for embarrassment, and it doesn’t reflect your personal hygiene habits. It is a sign something may be amiss, so let’s work through it.

Aerobic vaginitis (AV)

Aerobic vaginitis is strongly associated with foul, pungent vaginal odour¹¹. Similar to BV, aerobic vaginitis is associated with a drop in Lactobacillus dominance in the vaginal microbiome and sometimes an elevated pH (over 4.5).

Some AV-causing bacteria are lactic-acid bacteria (LAB), so the pH may be normal in a premenopause. Postmenopause, the pH can be very variable.

AV is the overgrowth of certain types of gut bacteria, typically E. coli, Staphylococcus aureus, group B Streptococcus (GBS), and Enterococcus faecalis¹², which enjoy greater access to oxygen to multiply, hence the name.

A lost tampon

A lost or forgotten tampon can also produce a rotting smell. This odour gets stronger the longer the tampon stays in, as bacteria that thrive in a blood-rich environment multiply.

Leaving a tampon in the vagina for over 6-8 hours¹³ comes with an increased risk of toxic shock syndrome (TSS) – a rare but dangerous condition where bacteria spread through the body, releasing harmful toxins. The quality of your menstrual products makes no difference¹⁴.

So when using tampons, follow the guidelines¹⁵ and your menstrual flow, using the lowest absorbency tampon¹⁶ for your flow.

Menstruation

A milder odour can occur during bleeding. Change pads, tampons, cups or other menstrual products around every 4-6 hours.

Fishy, meaty, or cheesy vaginal odour

Vaginal odour can resemble scents from a farm or the sea. It is completely normal for certain microbes to give off scents reminiscent of fish, meat or cheese – all food has bacteria in it too.

Bacterial vaginosis

The microbe most commonly associated with BV – G. vaginalis¹⁷ – produces specific chemicals¹⁸ that create a strong fishy or even putrid fish-like odour. These chemicals⁷ include trimethylamine (TMA), putrescine, and cadaverine.

In clinic, the most common thing I see behind a persistent fishy or foul smell isn’t poor hygiene – it’s a microbiome that’s lost its footing, with the protective lactobacilli squeezed out. Once we modify the microbiome, the symptoms naturally disappear and the protective species ensure the vagina smells normal (read: not fishy!) again.

A study¹⁹ from 2002 examining TMA levels in the vaginal fluids of women with BV found TMA in all those with high vaginal bacterial diversity (Nugent score 7-10). TMA was either absent or present in small amounts in those with Lactobacillus-dominant microbiomes (Nugent scores 0-3).

Trichomoniasis

A fishy odour²⁰ can be caused by trichomoniasis, an STI caused by a parasite called Trichomonas vaginalis.

The digestive system and urogenital tract

Fishy vaginal odour⁷ can also be linked to non-bacterial conditions like urinary incontinence, malignant ulcers¹, trimethylaminuria²¹, or chronic constipation.

Several studies have found that some types of gut bacteria²² increase the production of trimethylamine (TMA), the fishy odour chemical. These bacteria include Anaerococcus, Providencia, Edwardsiella, Clostridium, Collinsella, Desulfovibrio, Lactobacillus, and Proteus⁷.

Semen, sex, and inflammation

Since the pH of semen²³ is naturally higher than the ideal vaginal pH, it can temporarily raise the vaginal pH. This can result in a fishy, meaty, or cheesy odour²⁴.

A sulphur-like, chickeny odour is also linked to the interaction between sweat and skin bacteria. This may be more noticeable after sex when you have become hot and sweaty.

Bleach or ammonia vaginal odour

A sign of bacterial vaginosis

Although bacterial vaginosis typically presents with an unpleasant, fishy odour, sometimes an ammonia-like vaginal odour can be associated with BV, particularly in cases driven by an overgrowth of Prevotella bivia.

A study²⁵ from 1997 found that when P. bivia was cultured with certain nutrients, it produced high levels of ammonia, which then promoted the growth of G. vaginalis.

Discharge and sweat

Discharge or sweat, plus small amounts of urine, can give vaginal odour an ammonia or urine-like quality. Those with urinary incontinence may find this more of a problem, with small urine leaks throughout the day.

Sour, tangy, vinegar, yogurt, or bread vaginal odour

When vaginal odour is more sourdough than regular yeasty bread, it might be a good sign – a sour, tangy vaginal odour can mean lots of protective lactobacilli. But a regular bread smell might mean a yeast infection.

A healthy vagina’s acidic environment (where Lactobacillus thrives, keeping disruptive microbes in check) maintains a pH between 3.8 and 4.5, producing this pickled or fermented odour.

Metallic vaginal odour

Period blood

Metallic vaginal odour is associated with menstrual blood, which has a high iron concentration. This is normal.

Light bleeding after sex can also amplify this metallic, tinny scent. Unexplained mid-cycle bleeding or spotting might also take on this odour.

If bleeding or spotting is due to an infection, such as an STI or pelvic inflammatory disease (PID), see a doctor.

Fruity, sweet, bittersweet, or molasses vaginal odour

Crotch sweat

At times, crotch sweat interacts with skin bacteria to produce a fruit or grapefruit odour⁷. Some microbes within a healthy vaginal microbiome can also give off molasses-like, earthy odours.

What we don’t know about vaginal odour

There is a significant lack of research on the various vaginal odours and their causes.

Apart from fishy odours – and the offensive, misogynistic narratives that tie these smells to a woman’s hygiene and worth – there isn’t a great deal of research into vaginal odours.

Getting to know what is normal for you matters.

Minor changes in vaginal odour are normal and expected. Anything that smells unpleasant, fishy or foul, though, needs a doctor.

Above all, get acquainted with your own vaginal odour and how it changes across your menstrual cycle. You will instinctively know when something isn’t right, and when in doubt, refer back to this guide, see your doctor, and get a comprehensive vaginal microbiome test.

Frequently asked questions

Why does my discharge smell fishy?

A fishy smell, especially one that gets stronger after sex or around your period, is the classic sign of bacterial vaginosis (BV). It happens when protective lactobacilli are crowded out by disruptive bacteria like Gardnerella and Prevotella, the vaginal pH rises above 4.5, and those bacteria give off amines such as trimethylamine, putrescine and cadaverine – the same compounds behind the smell of off fish.

A fishy smell with frothy, yellow-green discharge and soreness can also point to trichomoniasis, an STI. Either way, a genuinely fishy odour is worth a swab. You can read how to treat BV, and a comprehensive vaginal microbiome test can show exactly which bacteria are involved.

Is a slight vaginal smell normal?

Yes. A healthy vagina always has a smell, and it is not meant to be odourless or floral. Musky, tangy, sour, ‘of the sea’, or a bit metallic around your period – these are all within normal range and shift across your menstrual cycle.

What is not normal is a strong, foul, rotten or fishy smell, particularly with itching, unusual discharge, pain or bleeding. That is your cue to see a doctor rather than reach for a scented product.

Should I use a vaginal wash or douche for odour?

No. Douches, ‘feminine washes’, deodorants and scented wipes strip the protective lactobacilli that keep your vagina acidic, which makes odour and BV more likely, not less. They treat a normal smell as a problem and often create a real one.

The vagina cleans itself. Warm water on the vulva (the outside) is plenty. If there is a genuine odour, the fix is sorting out the bacteria, not masking the smell.

This article is general information, not personal medical advice. If your vaginal odour is strong, fishy, foul, or comes with itching, unusual discharge, pain, fever or bleeding, see your doctor or a qualified vulvovaginal practitioner for an assessment and swab.