A healthy vagina has a mild odor, often slightly sour or musky, and it shifts with your cycle, sex and sweat. Vaginal odor becomes a concern when it is new and strong: a fishy smell, a rotten smell, or an odor that comes with itching, burning, or a change in discharge[1][2].
The most common cause of a fishy vaginal smell is bacterial vaginosis (BV), a shift in vaginal bacteria rather than a hygiene problem[3]. This guide covers what normal smells like, what each type of vaginal smell can mean, why odor often gets worse after sex or your period, which remedies help and which backfire, and when to get checked.
Get medical help promptly if the odor comes with fever or pain in your pelvis or belly, a rotten smell that could be a forgotten tampon, bleeding between periods or after sex or menopause, or possible exposure to a sexually transmitted infection[4][5]. If you are pregnant, get any new odor checked: BV in pregnancy is linked to preterm birth[3].
What should a healthy vagina smell like?
A healthy vagina has a faint scent, not no scent. ACOG says a certain amount of vaginal odor is normal, and normal discharge is clear to white without a noticeable odor[1]. Reviews of body odor describe normal vaginal secretions as almost odorless or similar to yogurt[6].
Estrogen encourages lactobacilli, and these bacteria keep the vagina slightly acidic, which protects against harmful microbes[1]. Normal vaginal pH in the reproductive years is about 4.0 to 4.5, and slightly higher before puberty and after menopause[7].
"Normal" also varies between people. In a study of 396 women without symptoms, healthy vaginal communities fell into five groups, four led by different Lactobacillus species, and average pH ranged from 4.2 to 5.0 across ethnic groups[8]. Your baseline is what matters: ACOG defines abnormal discharge as a change in color, odor, amount or consistency from what is usual for you[1].
Vaginal smells chart: what each odor can mean
Use this as a guide to what to check, not as a diagnosis. Symptoms of the common infections overlap, and diagnosis needs a sample of discharge tested by a clinician[2].
| Smell | Common cause | Other signs | What to do |
|---|---|---|---|
| Mild, sour, tangy or yogurt-like | Healthy Lactobacillus-dominated microbiome[6] | Clear to white discharge, no itching | Nothing |
| Fishy, stronger after sex or during your period | Bacterial vaginosis[2] | Thin gray or white discharge; often no other symptoms | Get tested; treatment is prescription |
| Fishy or foul with yellow-green discharge | Trichomoniasis, an STI[9] | Vulvar irritation, sometimes pain on urination[2] | Get tested; partners need treatment too |
| Metallic, around your period | Blood in the vagina | Normal bleeding pattern | Nothing, if it fades after your period |
| Musky or skunky, worse after sweating | Groin sweat broken down by skin bacteria[6] | Smell is on the skin, not in discharge | Rinse, change into cotton underwear |
| Urine-like | Urine on the skin or leakage[6] | Often with urine leakage | Rinse; mention leaking to a clinician |
| Strong rotten smell | Forgotten tampon or other object[4] | Discharge, sometimes bleeding | Get it removed promptly |
| Foul, with watery or bloody discharge | Rarely, cervical or other cancers[5] | Bleeding after sex or menopause, pelvic pain | See a clinician soon |
Itching with thick, white, lumpy discharge usually means a yeast infection, which typically has no odor[2]. That is a useful clue: a strong smell makes yeast a less likely explanation[7].
Why does my vagina smell fishy?
A fishy vaginal odor usually comes from amines made by bacteria that thrive when lactobacilli decline. In a 1986 study, trimethylamine, the compound behind the smell of spoiling fish, was found in all 11 fishy-smelling vaginal samples and in none of the 10 without odor[10]. Later work showed that bacteria produce this trimethylamine inside the vagina; it is not simply excreted from the rest of the body[11].
BV is the usual source. It replaces lactic-acid-producing lactobacilli with high levels of anaerobes such as Gardnerella vaginalis, Prevotella and Mobiluncus[3]. A fishy odor is one of the four clinical criteria for BV, along with thin discharge, pH above 4.5 and "clue cells" under the microscope[3]. The WHO puts global BV prevalence among women of reproductive age at 23% to 29%[12].
Trichomoniasis can smell similar. It is the most common non-viral STI worldwide, and 70% to 85% of people with it have few or no symptoms[9]. When symptoms do appear, the discharge can be malodorous and yellow-green[9].
Fishy vaginal odor after sex
Semen is alkaline, with a pH of about 8.0[7]. Making BV discharge more alkaline intensifies its fishy smell, which is the basis of the clinic "whiff test"[10][3]. ACOG notes that BV odor may be stronger after sex[2]. If the smell appears mainly after unprotected sex, that pattern is worth mentioning when you get tested.
Vaginal odor after your period
Menstrual blood is slightly alkaline and can raise vaginal pH[7]. BV becomes more common during menses[3], and in a 16-week study of 32 healthy women, shifts in vaginal communities tracked the menstrual cycle and sexual activity[13]. A metallic smell that fades after your period is normal; a fishy smell that lingers afterward is not.
Why do I smell if I don't have BV?
Two less common explanations exist. Sweat or urine near the vulva can be mistaken for vaginal odor, and smells from the anal area can be too[6]. Rarely, trimethylaminuria ("fish odor syndrome") causes a fishy smell in breath, sweat, urine and vaginal fluid because the liver cannot break down trimethylamine from foods rich in choline and carnitine[14]. A normal swab test with a fishy body odor everywhere, not just vaginally, is a reason to ask about it.
What the vaginal microbiome has to do with odor
Odor is a readout of which bacteria dominate. Lactobacillus-dominated communities make lactic acid and keep pH low; the lactobacilli-depleted community type (called CST IV) holds more strict anaerobes[8].
Those anaerobes are the odor makers. A genetic analysis predicted that relatively few vaginal bacteria, including Prevotella, Megasphaera, Dialister and Peptostreptococcus, can make biogenic amines, and that putrescine, cadaverine and tyramine were significantly higher in CST IV than in Lactobacillus-dominated communities in 37 women[15]. Putrescine and cadaverine smell like spoiled fish or rotting meat[6].
The amines may also feed the imbalance. In 149 samples collected over time, rising cadaverine, putrescine and tyramine predicted a shift away from Lactobacillus crispatus dominance toward BV, and in the lab, putrescine slowed lactobacilli growth and reduced their lactic acid output[16]. That is lab and observational evidence, not proof, but it suggests why masking the smell does not address the cause.
Other causes: menopause, pregnancy and foreign objects
Vaginal odor during menopause
Falling estrogen thins the vaginal lining and reduces discharge[1]. In a two-year study of 750 women aged 35 to 60, low-Lactobacillus communities became more common through perimenopause and after menopause, and L. crispatus dominance after menopause was linked to lower odds of vaginal atrophy[17]. Atrophic vaginitis can cause discharge and irritation and is treated with vaginal estrogen[2].
Vaginal odor during pregnancy
Discharge often increases in pregnancy, and hormonal changes can shift the balance of yeast and bacteria, so vaginal infections are more common[1]. Symptomatic BV in pregnancy is linked to premature rupture of membranes and preterm birth, so the CDC recommends treating all pregnant people who have symptoms[3].
A forgotten tampon or other object
A forgotten tampon or other foreign body can cause a foul odor and discharge[4]. If you cannot find or remove it yourself, see a clinician promptly rather than waiting for the smell to pass.
How to get rid of vaginal odor and a fishy smell: what helps and what backfires
The fastest way to get rid of an abnormal vaginal odor is to treat its cause. BV and trichomoniasis need prescription treatment, usually metronidazole or clindamycin for BV and metronidazole for trichomoniasis[3][9]. Home remedies cannot tell which infection you have, and over-the-counter yeast treatments can delay the right diagnosis[2].
| Remedy | What the evidence says | Verdict |
|---|---|---|
| Douching or vaginal washes | Regular douching raised BV risk (RR 1.21) in 3,620 women[18]; may increase BV relapse[3] | Avoid |
| Feminine sprays, deodorants, scented products | ACOG says they are not recommended and may make things worse[1] | Avoid |
| Plain water or fragrance-free soap on the vulva only | Recommended by ACOG[1] | Use |
| Cotton-crotch, loose underwear | Recommended to let air circulate[1][4] | Use |
| Condoms | BV is linked to new partners and lack of condom use[3] | Use |
| Vaginal steaming | MedlinePlus warns it may increase infection risk[4] | Avoid |
| Probiotics | No studies support them as BV treatment or add-on, per the CDC[3] | Optional, after treatment |
Probiotics are the remedy people ask about most. One randomized trial of 228 women found that a vaginal L. crispatus product, used after metronidazole gel, cut BV recurrence at 12 weeks from 45% to 30%[19], but it is not yet available to buy[3]. Our guide to probiotics for vaginal health covers which strains have trial data, and probiotics for BV and yeast infections covers using them alongside treatment.
Also worth knowing: BV often comes back. The CDC advises returning for evaluation if symptoms recur, and a different or longer treatment plan may be needed[3].
When to see a doctor
See a clinician if any of these apply[4][2][5]:
- a new fishy, foul or rotten odor, or one that lasts more than a week despite gentle care;
- a sudden change in the color, amount or consistency of discharge;
- itching, burning, redness or swelling, or burning when you urinate;
- fever, or pain in your pelvis or belly;
- bleeding between periods, after sex or after menopause;
- possible exposure to an STI, or a partner with symptoms;
- any new odor or discharge while pregnant.
For the most accurate test results, skip vaginal medicines for 3 days before the visit, and do not douche or have sex beforehand[2].
This article is for general educational purposes and is not medical advice. Vaginal odor has many causes, and only an exam and testing can identify yours. Talk to a qualified healthcare professional before starting any treatment, particularly if you are pregnant, immunocompromised, taking prescription medication, or managing a diagnosed condition.
Frequently Asked Questions
Is it normal to smell a little bit fishy?
A faint, mild scent is normal, but a fishy smell usually is not. ACOG describes normal discharge as clear to white with no noticeable odor, and a fishy odor is one of the diagnostic signs of bacterial vaginosis and can also occur with trichomoniasis. If the fishy smell is new, keeps coming back, or gets stronger after sex or your period, a quick swab test can tell you what is going on.
Why can I smell myself through my pants?
Often it is sweat rather than the vagina itself. The groin and perineum have apocrine sweat glands, and their sweat is odorless until skin bacteria break it down, which produces a musky or pungent smell when you sweat heavily. A strong fishy smell that you notice through clothing is different: that points toward bacterial vaginosis or trichomoniasis and is worth testing.
Why does it smell when I open my legs?
Often it is genital sweat. The genital and perineal area has apocrine sweat glands, and their sweat is odorless until skin bacteria break it down into pungent compounds; researchers note that genital sweat is easily mistaken for vaginal odor. A smell like this sits on the skin and usually fades after rinsing with water. If the smell comes from discharge instead, especially a fishy or rotten one, it is more likely vaginal and worth getting checked.
What does white, milky discharge with a fishy smell mean?
Thin, milky discharge that coats the vaginal walls, together with a fishy odor, matches two of the four clinical signs of bacterial vaginosis; the other two are a vaginal pH above 4.5 and clue cells under the microscope. A clinician needs three of the four to diagnose it. Normal discharge is also clear to white, but it does not have a noticeable odor.
Why do I smell bad down there even with good hygiene?
Because the most common cause of a bad vaginal smell, bacterial vaginosis, is a shift in vaginal bacteria, not a hygiene problem. Extra washing can make it worse: in a study of 3,620 women, regular douching raised the risk of BV by about 21%. Wash only the vulva with water or plain unscented soap, and get tested if a fishy or foul smell persists.
Why does it smell bad down there but not fishy?
A metallic smell around your period comes from blood. A musky or skunky smell is usually sweat broken down by skin bacteria. A urine-like smell can come from urine on the skin. A strong rotten smell can mean a forgotten tampon or other object, which needs prompt removal. A foul smell with blood-stained or watery discharge, bleeding between periods or pelvic pain needs a clinician.
Will a fishy vaginal odor go away on its own?
Sometimes. The CDC notes that some women have short-lived shifts in vaginal bacteria while others have them for longer. But treatment is recommended for anyone with symptoms of bacterial vaginosis, and trichomoniasis can last months to years without treatment. If the smell lasts more than a few days or keeps returning, get a swab test rather than waiting.
Do probiotics get rid of vaginal odor?
The evidence is not strong enough to rely on them. CDC guidelines state that no studies support probiotic products as a replacement for, or add-on to, BV treatment. One trial of a vaginal Lactobacillus crispatus product used after antibiotics lowered BV recurrence from 45% to 30% at 12 weeks, but that product is not commercially available. Treat the cause first, then discuss probiotics with your clinician.
References
- American College of Obstetricians and Gynecologists. Vulvovaginal Health (FAQ190). ACOG Patient Resources. 2026. Available at: https://www.acog.org/womens-health/faqs/vulvovaginal-health ↩
- American College of Obstetricians and Gynecologists. Vaginitis (FAQ028). ACOG Patient Resources. 2025. Available at: https://www.acog.org/womens-health/faqs/vaginitis ↩
- Centers for Disease Control and Prevention. Bacterial Vaginosis. Sexually Transmitted Infections Treatment Guidelines, 2021. STI Treatment Guidelines. 2021. Available at: https://www.cdc.gov/std/treatment-guidelines/bv.htm ↩
- MedlinePlus Medical Encyclopedia. Vaginal itching and discharge - adult and adolescent. U.S. National Library of Medicine. 2025. Available at: https://medlineplus.gov/ency/article/003158.htm ↩
- National Cancer Institute. Cervical Cancer Symptoms. National Cancer Institute. 2022. Available at: https://www.cancer.gov/types/cervical/symptoms ↩
- Mogilnicka I, Bogucki P, Ufnal M. Microbiota and Malodor—Etiology and Management. International Journal of Molecular Sciences. 2020;21(8):2886. doi:10.3390/ijms21082886 ↩
- Lin YP, Chen WC, Cheng CM, Shen CJ. Vaginal pH Value for Clinical Diagnosis and Treatment of Common Vaginitis. Diagnostics. 2021;11(11):1996. doi:10.3390/diagnostics11111996 ↩
- Ravel J, Gajer P, Abdo Z, et al.. Vaginal microbiome of reproductive-age women. Proceedings of the National Academy of Sciences. 2010;108(Suppl 1):4680-4687. doi:10.1073/pnas.1002611107 ↩
- Centers for Disease Control and Prevention. Trichomoniasis. Sexually Transmitted Infections Treatment Guidelines, 2021. STI Treatment Guidelines. 2021. Available at: https://www.cdc.gov/std/treatment-guidelines/trichomoniasis.htm ↩
- Brand JM, Galask RP. Trimethylamine: the substance mainly responsible for the fishy odor often associated with bacterial vaginosis. Obstetrics and Gynecology. 1986;68(5):682-685. Available at: https://pubmed.ncbi.nlm.nih.gov/3763085/ ↩
- Wolrath H, Ståhlbom B, Hallén A, Forsum U. Trimethylamine and trimethylamine oxide levels in normal women and women with bacterial vaginosis reflect a local metabolism in vaginal secretion as compared to urine. APMIS. 2005;113(7-8):513-516. doi:10.1111/j.1600-0463.2005.apm_175.x ↩
- World Health Organization. Bacterial vaginosis (fact sheet). World Health Organization. 2025. Available at: https://www.who.int/news-room/fact-sheets/detail/bacterial-vaginosis ↩
- Gajer P, Brotman RM, Bai G, et al.. Temporal Dynamics of the Human Vaginal Microbiota. Science Translational Medicine. 2012;4(132):132ra52. doi:10.1126/scitranslmed.3003605 ↩
- Rehman HU. Fish odour syndrome. Postgraduate Medical Journal. 1999;75(886):451-452. doi:10.1136/pgmj.75.886.451 ↩
- Nelson TM, Borgogna JLC, Brotman RM, Ravel J, Walk ST, Yeoman CJ. Vaginal biogenic amines: biomarkers of bacterial vaginosis or precursors to vaginal dysbiosis?. Frontiers in Physiology. 2015;6:253. doi:10.3389/fphys.2015.00253 ↩
- Borgogna JLC, Shardell MD, Grace SG, et al.. Biogenic Amines Increase the Odds of Bacterial Vaginosis and Affect the Growth of and Lactic Acid Production by Vaginal Lactobacillus spp.. Applied and Environmental Microbiology. 2021;87(10):e03068-20. doi:10.1128/aem.03068-20 ↩
- Shardell M, Gravitt PE, Burke AE, Ravel J, Brotman RM. Association of Vaginal Microbiota With Signs and Symptoms of the Genitourinary Syndrome of Menopause Across Reproductive Stages. The Journals of Gerontology: Series A. 2021;76(9):1542-1550. doi:10.1093/gerona/glab120 ↩
- Brotman RM, Klebanoff MA, Nansel TR, et al.. A Longitudinal Study of Vaginal Douching and Bacterial Vaginosis--A Marginal Structural Modeling Analysis. American Journal of Epidemiology. 2008;168(2):188-196. doi:10.1093/aje/kwn103 ↩
- Cohen CR, Wierzbicki MR, French AL, et al.. Randomized Trial of Lactin-V to Prevent Recurrence of Bacterial Vaginosis. New England Journal of Medicine. 2020;382(20):1906-1915. doi:10.1056/nejmoa1915254 ↩