You've just removed your protection and there's this smell. Not exactly pleasant. You wonder if this is normal, if other women experience this too, or if you have a problem. In 80% of cases, this is perfectly normal. Menstrual blood has an odor, period. But there's a world of difference between a normal odor (slightly metallic or acidic) and an odor that signals infection (rotten fish, ammonia).
What comes out of your vagina during your period isn't just blood. It's a cocktail of blood, uterine lining, cervical secretions, and vaginal bacteria. This mixture, when exposed to air and trapped in a pad, naturally develops an odor. The problem is, you've been so taught to be ashamed of your body that you can't tell the difference between normal and what warrants a checkup.
The essentials (to stop freaking out)
Why Period Blood Smells More Than Regular Blood
The blood that comes out of your finger when you cut yourself smells almost nothing. Your period blood, on the other hand, smells much more. The difference? Menstrual blood is not pure blood.
The composition of menstrual blood
During your period, your body expels a complex mixture.
- Blood (red blood cells, white blood cells, platelets) which contains iron – hence the metallic smell
- Pieces of the endometrium (the uterine lining that breaks down), rich in proteins that ferment
- Cervical and vaginal secretions (mucus, phlegm) with their own pH and odor
- Bacteria from the vaginal flora (lactobacilli and others), which love blood and feed on it
- Dead cells of the vaginal wall which are constantly renewed
Upon contact with air and your body heat, this cocktail begins to ferment. Bacteria multiply. Iron oxidizes. Proteins break down. The result: an odor more pronounced than simple bleeding.
💡 pH plays a key role : Your vagina normally has an acidic pH (3,8-4,5) which limits bacterial growth. Menstrual blood has a neutral pH (7,4), which temporarily alkalizes your vagina and promotes the growth of certain odor-causing bacteria.
Different Period Smells and What They Mean
Not all smells are created equal. Some are normal, while others signal a problem that needs to be addressed. The complete guide to decoding what your nose is telling you.
1. Metallic Smell (Like Coins)
Why : Blood contains iron. When iron comes into contact with air, it oxidizes and produces that characteristic metallic odor. It's exactly the same phenomenon as when you touch a coin or have a nosebleed.
When it is more marked: At the beginning and end of your period, when your flow is light and it takes longer for the blood to come out. "Old" blood smells stronger than fresh blood.
✅ No action required : This smell will disappear on its own at the end of your period.
2. Slightly Acidic or Musky Odor
Why : Your healthy vagina contains lactobacilli (good bacteria) that produce lactic acid. This natural acidity gives it a slightly sour odor, sometimes compared to yogurt or sourdough. This is a sign that your vaginal flora is functioning properly.
Normal variations: The odor can be more or less pronounced depending on the phase of your cycle, your diet, your hydration and your level of physical activity.
✅ Sign of good health : This smell proves that your vaginal pH is balanced.
3. Rotten Fish Smell (Strong and Persistent)
Why : This is the typical sign of bacterial vaginosis (BV), the most common vaginal infection. It occurs when bad bacteria (anaerobes, in particular) Gardnerella vaginalis) take over the good ones (lactobacilli). These bacteria produce volatile amino compounds that smell like spoiled fish.
Aggravated by: Sexual intercourse (semen alkalizes the vagina), menstruation (blood increases pH), douching, stress, and certain antibiotics.
Associated symptoms: Grayish or whitish discharge, sometimes abundant, feeling of humidity, slight itching (not systematic).
⚠️ Consult Vaginosis is easily treated with antibiotics (metronidazole or clindamycin) in the form of tablets or vaginal gel. Left untreated, it can increase the risk of STIs and cause complications during pregnancy.
4. Rotting Smell (Extremely Strong)
Why : A tampon left in the vagina becomes a breeding ground for bacteria. The blood stagnates, ferments, and decomposes, producing an unbearable, rotten odor. This happens more often than you might think, especially at the end of your period or after intercourse that has pushed the tampon deep into the vagina.
Associated symptoms: Foul-smelling yellow-green discharge, fever, pelvic pain, general feeling of malaise.
🚨 Immediate action : If you can feel the string, remove it yourself. Otherwise, consult a doctor or go to the emergency room. A tampon left out for a long time can cause toxic shock syndrome (rare but serious).
5. Ammonia or Bleach Smell
Why : Can signal dehydration (concentrated urine running down your vulva), trichomoniasis (STI caused by a parasite), or sometimes a simple chemical reaction with your laundry detergent or shower gel.
Symptoms associated with trichomoniasis: Frothy yellow-greenish discharge, intense itching, burning when urinating, pain during intercourse.
⚠️ Action : Drink more water. If the odor persists for more than 2-3 days or is accompanied by other symptoms, seek medical help to rule out an STI.
6. Sweet or Yeasty Smell
Why : A sweet smell can be normal for some women, especially if you eat a lot of fruit. But when combined with itching, it can signal a vaginal yeast infection (a yeast infection). Candida).
Symptoms associated with mycosis: Thick white discharge (curdled milk appearance), intense itching, redness, burning, no strong odor (unlike vaginosis).
⚠️ Action : If this is your first time experiencing a yeast infection, consult a doctor to confirm the diagnosis. If it recurs, over-the-counter treatments are available (antifungal suppositories).
Odorous Discharge Before and After Period: What's Happening?
You may have noticed that odor isn't limited to active period days. Discharge before and after menstruation can also smell stronger. This is related to hormonal fluctuations and vaginal pH, which varies depending on the phase of your cycle.
Brown smelly discharge after menstruation
Brown discharge is oxidized blood that took longer to come out. This is "end-of-line" blood that's been around for several days. It's normal for it to smell stronger than at the beginning of your period. As long as the smell stays in the metallic/acidic range and disappears within a few days, don't worry.
Red flag: Smelly brown discharge (fishy) that persists for a week after the end of your period + itching = potential vaginosis to be treated.
Why It Smells Stronger With Some Protections
Not all period protection is created equal when it comes to odor. The type of protection directly influences the intensity of the odor you perceive.
Sanitary napkins (disposable or washable)
Why it smells more: The blood remains in contact with the air and macerates in the protection. Bacteria love this warm, humid environment and multiply rapidly, producing more odors.
Aggravated by: Chemicals in disposable pads (perfumes, bleaching agents) that interact with blood and create unpleasant artificial odors.
solution: Change every 4 hours at the most, even if the flow is light. Choose organic cotton pads or washable pads without chemicals.
Tampons and menstrual cups
Why it smells less: The blood stays inside the vagina, so less contact with air = less oxidation = less noticeable odor. You only really smell the odor when you withdraw.
Please note: If the tampon smells very strong (fishy, rotten) when removed, it is likely bacterial vaginosis. The tampon does not create the infection, it just reveals the odor that was already there.
solution: Change every 6-8 hours maximum (never more than 8 hours to avoid toxic shock syndrome). Empty the cup every 8-12 hours depending on the flow.
Period panties
Best compromise: They allow the intimate area to breathe better than disposable pads thanks to their technical fabrics (organic cotton, bamboo). Less maceration = less bacterial proliferation = less odor.
Bonus: No chemicals that could amplify odors or irritate your vulva.
solution: Change every 8-12 hours depending on flow. Rinse in cold water before washing to prevent the odor from setting into the fabric.
Protect Yourself Without Worrying
Whether you have a smelly period or not, our Period Panties offer you up to 12 hours of protection, breathe better than disposables and naturally limit odors thanks to their technical fabrics.
Bacterial Vaginosis: The Silent Infection Behind the Odors
If your period smells like rotten fish, chances are you have bacterial vaginosis (BV). It's the most common vaginal infection in women of reproductive age, yet 80% of women who have it don't even know it.
Vaginosis figures
- 30% of women have vaginosis at some point
- 80% are asymptomatic (have no visible symptoms)
- 50% recurrence rate within 12 months after treatment
- 3x more frequent in sexually active women
- Increased risk STIs (HIV, herpes, chlamydia) if untreated
How It Grows
Your vagina naturally harbors a delicate balance of bacteria. The "good" bacteria (lactobacilli) produce lactic acid, which maintains an acidic pH (3,8-4,5) that's hostile to bad bacteria. Vaginosis occurs when this balance is upset.
Factors that unbalance the vaginal flora
- Rules : Menstrual blood (pH 7,4) alkalizes the vagina and dilutes the protective lactobacilli. This is why many women develop vaginosis right after their period.
- Unprotected sex : Semen has an alkaline pH (7,2-8) which neutralizes vaginal acidity for several hours.
- Vaginal douching : Destroys good bacteria. Never do this.
- Antibiotics : Kills everything, good and bad bacteria.
- Chronic stress : Weakens the immune system and disrupts hormonal balance.
- Tobacco : Reduces protective lactobacilli.
- The IUD (coil) : May promote vaginosis in some women.
The Treatment
The good news: vaginosis is easily treated with antibiotics. The bad news: it tends to come back.
⚠️ Frequent recurrences
About 50% of women experience a relapse within a year. To limit recurrences: vaginal probiotics (lactobacilli), avoid douching, use condoms, limit frequent changes of partners, and do not smoke.
How to Reduce Period Odor (Without Hurting Yourself)
No woman likes a strong odor during her period. But be careful: some "solutions" do more harm than good. A guide to best practices that really work.
✅ What Really Works
Change your protections regularly : Every 4 hours for pads, 6-8 hours for tampons, 8-12 hours for Period Panties. Stagnant blood = bacteria feasting = odors exploding.
Wash your vulva (not your vagina) : 1-2x/day with lukewarm water or a mild, unscented soap (pH neutral or slightly acidic). Clean only the exterior (vulva, labia majora). Never the interior.
Dry well after showering : Gently dab with a clean towel. Moisture = a favorite playground for bacteria.
Portez des sous-vetements en coton : Cotton breathes. Synthetic materials (polyester, nylon) create condensation and promote maceration.
Avoid clothes that are too tight : Skinny jeans or ultra-tight leggings compress the area and prevent air circulation.
Choose chemical-free protection : Organic cotton for pads and tampons, technical fabrics for Period Panties. Perfumes and bleaching agents in disposable protection can irritate and worsen odors.
Hydrate yourself well : Water dilutes your urine and reduces ammonia odors that can mix with menstrual odor.
❌ What Does More Harm Than Good
Vaginal douching : Absolute disaster. They destroy your protective vaginal flora, increase the risk of infections, and worsen odor in the long run. The vagina is self-cleaning.
Intimate deodorants : Toxic marketing. These products irritate the delicate skin of your vulva, disrupt the pH, and can cause burning. They mask the odor without treating the cause.
Scented intimate wipes : Same problem. Synthetic perfumes and alcohol irritate and unbalance.
Scented protections : Perfume only masks the natural smell and can create an even more unpleasant cocktail.
Wearing a tampon "as a precaution" outside of menstruation : The tampon absorbs all your good protective bacteria, dries out the vagina and promotes infections.
Full body hair removal : Pubic hair plays a protective role. Shaving it completely increases the risk of irritation, micro-cuts, and infections.
🌸 Best Practices for Maintaining Intimate Hygiene →
Misconceptions About Period Odor
The internet is full of myths about intimate odors. We separate the truth from the fiction.
💭 "Everyone can smell my period"
FALSE
Unless you have a severe, untreated infection, period odor remains imperceptible to others. You smell it because you're close to your body, hypersensitive to your own odors, and conditioned to be ashamed. Studies show that even intimate partners typically don't detect menstrual odor.
💭 "Diet radically changes the smell of your period"
RATHER FALSE
Unlike sweat (where garlic, onion, or alcohol can actually change body odor), diet has a very limited impact on vaginal and menstrual odor. A few foods like asparagus can slightly change the smell of urine flowing over the vulva, but that's about it. The myth that eating pineapple makes your vagina sweeter? Pure marketing with no scientific basis.
💭 "If it smells, it's because I'm not washing enough."
FALSE
A strong odor is rarely linked to poor hygiene. It is almost always an imbalance in the vaginal flora (vaginosis) or an infection. On the contrary, excessive hygiene (vaginal douching, frequent cleaning with harsh soaps) destroys the good bacteria and worsens the problem.
💭 “A healthy vagina should not smell”
COMPLETELY FALSE
All organs have an odor. The vagina isn't supposed to smell like roses or nothing at all. A slightly sour, musky, or metallic odor (during menstruation) is perfectly normal and a sign of good health. This toxic myth wreaks havoc on women's self-esteem.
💭 "Vaginosis is an STI"
FALSE
Bacterial vaginosis is NOT a sexually transmitted infection. It is an imbalance of the vaginal flora. It is more common in sexually active women, but it can occur in anyone, even virgins or postmenopausal women.
Summary Table: When to Worry (or Not)
To help you find your way around easily, here is a table that sums everything up.
The 3 red flags that require rapid consultation
- Smell of rotten fish which persists + grayish discharge = Bacterial vaginosis
- Unbearable smell of putrefaction = Tampon or foreign body forgotten
- Strong odor + fever + pain = Potentially serious infection
Stop Feeling Guilty About Normal Function
Menstrual blood has an odor. Period. It's a mixture of blood, uterine lining, secretions, and bacteria that, when exposed to air and under protective clothing, naturally develops a metallic or slightly acidic odor. In 80% of cases, this odor is completely normal and imperceptible to others. The odor becomes problematic when it resembles rotten fish (bacterial vaginosis), putrefaction (forgotten tampon), or is accompanied by other symptoms (itching, abnormal discharge, fever). These situations are easily treated with antibiotics or simple foreign body removal.
To limit odors, change your protection regularly, choose cotton and breathable materials, wash your vulva (not your vagina) with a mild soap, and moisturize. And above all, never use vaginal douches, intimate deodorants, or perfumed products that destroy your protective flora. Your body is functioning normally. The odor of your period is not a defect to be hidden; it's a health indicator to be monitored without becoming obsessed with it.
Sources & Scientific References
This article is based on recent scientific studies and verified medical data regarding vaginal and menstrual health.
Bacterial vaginosis and vaginal pH
- Peebles K, Velloza J, Balkus JE, McClelland RS, Barnabas RV. (2019). High Global Burden and Costs of Bacterial Vaginosis: A Systematic Review and Meta-Analysis. Sex Transm Dis. DOI: 10.1097/OLQ.0000000000001052
- Muzny CA, Kardas P. (2020). A Review of Current Evidence Linking Bacterial Vaginosis to Preterm Birth. Curr Opin Obstet Gynecol. DOI: 10.1097/GCO.0000000000000596
- Smith SB, Ravel J. (2017). The vaginal microbiota, host defense and reproductive physiology. J Physiol. DOI: 10.1113/JP271694
Vaginal flora and menstrual cycle
- Eschenbach DA, Thwin SS, Patton DL, et al. (2000). Influence of the normal menstrual cycle on vaginal tissue, discharge, and microflora. Blink Infect Dis. DOI: 10.1086 / 314965
- Srinivasan S, Fredricks DN. (2008). The human vaginal bacterial biota and bacterial vaginosis. Interdiscip Perspect Infect Dis. DOI: 10.1155/2008/750479
Impact of menstrual pH
- Boskey ER, Telsch KM, Whaley KJ, Moench TR, Cone RA. (2001). Acid production by vaginal flora in vitro is consistent with the rate and extent of vaginal acidification. Infect Immune. DOI: 10.1128/IAI.69.10.5763-5772.2001
Vaginal odor and perception
- Amsel R, Totten PA, Spiegel CA, Chen KC, Eschenbach D, Holmes KK. (1983). Nonspecific vaginitis: diagnostic criteria and microbial and epidemiologic associations. Am J Med. DOI: 10.1016/0002-9343(83)91112-9
Note: DOI links provide direct access to the original scientific publications. This article was written in accordance with current medical knowledge and will be updated regularly.
Medical Warning: This article is for informational purposes only and is not a substitute for professional medical advice. If you experience unusual symptoms, persistent odor, or pain, consult a gynecologist, midwife, or general practitioner.
