The short answer: Period blood usually has a mild smell, and that is normal. Most often it smells slightly metallic, a bit like coins, because blood contains iron. It can also smell a little sweet or tangy, and it turns musty if it sits on a pad or in underwear for hours. A strong fishy smell, or a rotten smell like spoiled meat, is not normal. Fishy can point to bacterial vaginosis, and rotten can mean a forgotten tampon or an infection, so both need a doctor.
Why does period blood smell at all?
Your period is not just blood. It is a mix of blood, the tissue that lined your womb, mucus from your cervix and normal vaginal fluid. Each of these has its own faint smell, and together they make the scent you notice during your period.
Once that mix leaves your body, it meets air and the bacteria that live on your skin. The longer it sits on a pad, a liner or fabric, the more those bacteria break it down, and the stronger the smell gets. That is why a fresh pad smells of very little, while the same pad worn all day can smell much stronger.
Your vagina also has its own community of friendly bacteria, mostly a type called lactobacilli, which keep it slightly acidic. Blood is less acidic, so during your period the balance shifts a little. For most people this makes no difference.
So a smell on its own is not a sign that something is wrong, or that you are not clean. What matters is the type of smell, how strong it is, and whether other symptoms come with it.
Normal period smells and what causes them
Metallic or like coins
This is the most common period smell. Cleveland Clinic describes it as smelling like copper coins. Blood carries iron in haemoglobin, the protein that moves oxygen around your body, and that iron gives blood its metallic note. It is often strongest on your heaviest days, when there is more fresh blood.
Slightly sweet or tangy
A mild sweet, sour or tangy smell is also common. It comes from the friendly bacteria in your vagina and the slightly acidic fluid they produce. Many people notice the same faint tang from their discharge at other times of the month. It is a sign of a vagina doing its usual job.
Musty or stale
Blood that has been sitting on a pad, liner or period product for many hours can start to smell stale or musty. This is the bacteria on your skin and in the product breaking it down. The fix is simple: change more often. The smell should go once you change and wash.
Sweaty or body-odour smell
The groin has plenty of sweat glands, and heat, tight clothes and stress all make you sweat more. Cleveland Clinic notes that a sweaty smell can happen when you are stressed and sweating more. In an Indian summer, a long school day in a uniform or a crowded commute, that sweat can mix with period blood and make the smell more noticeable.
Period smells at a glance
| What it smells like | Likely reason | What to do |
|---|---|---|
| Metallic, like coins | Iron in fresh blood | Nothing, this is normal |
| Slightly sweet, sour or tangy | Healthy vaginal bacteria | Nothing, this is normal |
| Musty or stale | Blood left too long on a product or fabric | Change more often and wash the outside with water |
| Sweaty | Heat, tight clothing, stress | Breathable cotton underwear, change out of damp clothes |
| Strong and fishy | Often bacterial vaginosis, sometimes trichomoniasis | See a doctor for a simple test |
| Rotten, like spoiled meat | Forgotten tampon or other object, or infection | Check for a tampon and see a doctor the same day |
Why products and fabric left too long start to smell
Many people think the smell is coming from inside them, when it is really coming from the pad. Blood on its own smells of very little at first. It is the warm, damp mix of blood, sweat and skin bacteria trapped against your body that builds the stronger smell over a few hours.
A few everyday habits make this worse:
- Stretching one pad too long. On a busy day at school, college or work, it is tempting to wait until you get home. ACOG, the American College of Obstetricians and Gynecologists, advises changing a pad at least every 4 to 8 hours, or whenever it feels full, wet or uncomfortable.
- Forgetting about light days. On the last day or two, a pad may look nearly clean, so it stays on all day. Old, slow blood darkens and can smell stronger, even in small amounts.
- Damp underwear. In the monsoon, clothes that have not fully dried can smell musty before you even put them on, and that adds to any period smell.
- Reusables not washed or dried well. A cloth pad or period panty that is put away slightly damp, or not rinsed until the water runs clear, can hold on to a smell.
Smells that are not normal
Fishy smell
A strong fishy smell is the classic sign of bacterial vaginosis (BV), a common imbalance of the bacteria in the vagina. The NHS says the smell is often stronger after sex, and the discharge may turn thin, watery and greyish-white. BV is not a sexually transmitted infection.
The smell can seem worse during or just after your period, because blood is less acidic than the vagina's usual fluid. If a fishy smell keeps coming back after every period, that pattern is worth mentioning to your doctor. Trichomoniasis, a sexually transmitted infection, can also cause a fishy or musty smell, often with green, yellow or frothy discharge. Our guide to vaginal infections covers the signs and treatment of each in detail.
Rotten or very strong smell
Cleveland Clinic says a forgotten tampon or another object can cause a strong smell like rotten meat. It happens more often than people think, especially when you insert a second tampon without removing the first, or at the very end of a period when you may lose track.
If you notice a sudden, very strong rotten smell, wash your hands and gently feel inside your vagina for a string or object. If you find one and can remove it easily, do so, and still see a doctor, because a lingering infection may need treatment. If you can't reach it, don't keep trying: a doctor can remove it quickly and without fuss.
Smell plus other symptoms: red flags
A smell is rarely the only clue to an infection. These combinations are worth taking seriously:
- A fishy smell with thin grey or watery discharge.
- Any strong smell with green, yellow or frothy discharge.
- Smell with itching, burning, soreness or pain when you pee.
- Smell with pelvic pain, pain during sex or bleeding between periods.
- Smell with a fever or feeling generally unwell.
- A smell that carries on after your period has finished, even though you have been changing often.
Spotting is a separate clue. If you are noticing brown or pink stains between periods, the timing matters. Our guides to ovulation spotting, spotting before your period and brown spotting after sex explain what each pattern can mean. If you are curious about the colour of your blood, the period blood colour chart covers that, and grey blood with a bad smell is one of the combinations that needs a check.
See a doctor if
- You notice a strong fishy smell, especially if it keeps returning after your period or after sex.
- Your discharge changes colour or texture, becoming grey, green, yellow, frothy or thick and lumpy.
- You have itching, burning, soreness or pain when you pee along with the smell.
- The smell lasts more than a few days after your period ends.
- You have bleeding between periods, after sex or after menopause.
- You are pregnant and notice any new smell or change in discharge.
- You think a tampon, condom or other object may be stuck, even if you feel well.
A gynaecologist or your family doctor can usually tell what is going on with a quick examination and a vaginal swab. Most causes, including BV, are treated simply with tablets, gel or cream. Doctors see this every day, so there is no need to feel embarrassed.
Get urgent help if
A forgotten tampon or menstrual cup can rarely lead to toxic shock syndrome (TSS), a serious illness caused by bacteria. The NHS lists signs such as a high temperature or feeling hot and shivery, flu-like symptoms, muscle aches and a sandpaper-like rash. Call 112 or 108, or go to the nearest hospital emergency department, if you have any of these while using or soon after using a tampon or cup:
- A sudden high fever, vomiting or diarrhoea.
- Feeling faint, dizzy or confused.
- Difficulty breathing.
- Skin, lips or tongue that look blue, grey, pale or blotchy.
Remove the tampon or cup if you can, and tell the doctor you were using one. Also get same-day help for a bad smell with fever and severe pain in your lower tummy, or after a recent birth, miscarriage or abortion.
Hygiene habits that keep period smell down
You don't need special products to smell fresh during your period. Simple, regular habits do most of the work.
Change on time
Change pads at least every 4 to 8 hours, and more often on heavy days. Follow the packet for tampons and cups, and never leave a tampon in longer than recommended. If you tend to forget on busy days, set a reminder on your phone for lunchtime.
Wash the outside only
Your vagina cleans itself. Wash your vulva, the outer area, once or twice a day with plain water. The NHS advises warm water and a mild, non-perfumed soap if you want to use one. If you prefer a dedicated product, Fabpad's intimate wash is mild, pH 3.5 and meant for the outside only. Pat dry with a clean towel, and wipe front to back after using the toilet.
Choose breathable underwear
Cotton underwear lets air move and dries faster than synthetic fabrics. Change out of sweaty clothes after sport or a long commute, and make sure every pair is fully dry before you wear it, which takes extra care in the monsoon.
Wash reusables properly
If you use period panties, rinse them in cold water until the water runs clear, then wash gently with a mild detergent or a panty wash, by hand or on a gentle cycle in a wash bag. Skip hot water, bleach and fabric softener. Dry them fully in the sun, not the shade, before putting them away. A period panty is worn on its own and can be worn for up to 8 hours depending on flow, so change it within that time. Our guide on how to wash period panties goes step by step.
Myths about period smell
Myth: Douching keeps you fresh. Rinsing inside the vagina with water, vinegar, antiseptic or anything else washes away the friendly bacteria that protect you. The NHS and Cleveland Clinic both advise against it, because it can raise your risk of infection, including BV, which is the very thing that causes a fishy smell.
Myth: Scented pads, sprays and wipes stop the smell. They only cover it for a short time, and the perfumes can irritate delicate skin. The NHS lists perfumed products used in or around the vagina as a risk factor for BV. Fabpad's disposable pads and liners are fragrance-free for this reason.
Myth: Period smell means you are unclean. A mild metallic or tangy smell is normal for everyone who has periods. It has nothing to do with how clean you are.
Myth: Home remedies inside the vagina help. Curd, neem, alum, garlic or tea tree oil may be suggested by relatives or online videos, but they can irritate the skin and there is no good evidence they help. If the smell is unusual, a doctor's test is quicker and safer.
Frequently asked questions
Why does my period smell like fish? A fishy smell is not a normal period smell. It is most often caused by bacterial vaginosis, which is common and easy to treat with medicines from a doctor. It can seem stronger during your period because blood changes the acidity of the vagina.
Why does my period blood smell like metal or coins? Blood contains iron, which gives it a metallic smell. This is completely normal and often strongest on your heaviest days.
Is it normal for my period to smell worse some months? Yes, it can vary. Heat, sweating, stress, how often you change and how heavy your flow is all make a difference. If the smell becomes fishy or rotten, or comes with itching or unusual discharge, see a doctor.
Can other people smell my period? A normal period smell is very faint and usually only you notice it. Changing on time, wearing breathable underwear and washing the outside with water keeps it that way.
Why does my period smell bad at the end? Near the end, blood flows slowly and is older, and a pad that looks almost clean may stay on for longer. Both can give a stronger, stale smell. Change as often on light days as on heavy ones.
Can a period panty make period smell worse? Not if it is changed and washed properly. Wear it for up to 8 hours depending on flow, rinse it in cold water until clear, wash gently and dry it fully in the sun. A pair that is put away damp may smell musty.
Should I use a scented intimate wash during my period? No. Perfumed products can irritate the skin and upset the vagina's balance. Plain water is enough. If you use a wash, choose a mild one and keep it to the outside only.
Related reading
- What a Healthy Period Looks Like: Flow, Colour, Length and Symptoms
- Normal Vaginal Discharge: What to Expect Through the Month
- Vaginal Infections: Signs, Causes and How to Prevent Them
- Period Blood Colour Chart: What Each Shade Means
This article is for general information and doesn't replace advice from your doctor.
Sources: Cleveland Clinic: Vaginal Odor: Types, Causes, Diagnosis and Treatment, NHS: Bacterial vaginosis, NHS: Vaginal discharge, NHS: Toxic shock syndrome, ACOG: Your First Period