A fishy vaginal odor is almost always caused by an overgrowth of certain bacteria, and the most common culprit is bacterial vaginosis (BV). The good news: BV is treatable, and many of the habits that prevent it are simple changes you can start today. Understanding what’s behind the smell is the fastest way to get rid of it for good.
Why It Smells Fishy in the First Place
Your vagina naturally contains a community of bacteria, mostly from the Lactobacillus family, that keep things slightly acidic and balanced. When that balance shifts and other types of bacteria multiply, they produce compounds called amines, which have a distinctly fishy smell. This shift is what doctors call bacterial vaginosis.
BV produces a thin, white or gray discharge along with that strong fish-like odor, which often becomes more noticeable after sex. It’s not a sexually transmitted infection, though sexual activity can trigger it. Roughly one in three women of reproductive age will deal with BV at some point.
Trichomoniasis, a sexually transmitted infection caused by a parasite, can also produce a fishy smell with a clear or white discharge. Because the symptoms overlap with BV, a healthcare provider may need to test a sample of your discharge to tell them apart. The treatments are different, so getting the right diagnosis matters.
What Actually Clears the Odor
If the smell has persisted for more than a few days, doesn’t improve with basic hygiene changes, or comes with unusual discharge, you likely need treatment for BV or another infection. A provider will typically prescribe either an oral antibiotic taken twice a day for seven days or a vaginal gel or cream applied for five to seven days. Both approaches are effective, and most people notice the odor fading within the first couple of days of treatment.
For BV that keeps coming back, some providers recommend boric acid vaginal suppositories as a follow-up. Clinical protocols use a 600 mg dose inserted once daily for up to 14 days. Boric acid is not safe during pregnancy or breastfeeding, and it should never be taken by mouth. It’s available over the counter, but it’s best used under guidance from a provider, especially if you’re dealing with recurrent episodes.
Habits That Restore and Protect Your Balance
Stop Douching
Douching is the single most counterproductive thing you can do for vaginal odor. It feels like a logical fix, but it flushes out the protective bacteria your body needs. A large multisite clinical study found that women who douched within the past six days were nearly twice as likely to develop an upper genital tract infection compared to women who didn’t douche at all. Those who douched more than once a month also had significantly elevated risk. The vagina is self-cleaning. Warm water on the outside is all you need.
Switch to Cotton Underwear
Synthetic fabrics trap moisture and heat, creating the exact environment that odor-causing bacteria thrive in. Cotton is breathable and wicks away sweat, keeping things drier throughout the day. If you see underwear marketed as having a “cotton crotch panel” in otherwise synthetic fabric, that small panel doesn’t fully protect you. The Cleveland Clinic recommends going with 100% cotton for the best results.
Watch Your Sugar Intake
High-sugar diets can reduce the population of protective bacteria in the vagina, creating an imbalance that makes infections more likely. This doesn’t mean you need to overhaul your entire diet, but if you’re dealing with recurring odor or infections, cutting back on added sugars is a low-effort change worth trying.
Practice Smart Post-Sex Hygiene
Semen is alkaline, which temporarily raises your vaginal pH and can make a fishy smell more pronounced if your bacterial balance is already off. Urinating after sex and gently rinsing the vulva with water can help your body return to its normal acidity faster. Avoid using scented wipes, sprays, or soaps internally. These products disrupt the same bacterial balance you’re trying to protect.
What About Probiotics?
The idea behind vaginal probiotics is straightforward: replenish the beneficial bacteria that keep odor-causing organisms in check. Two specific strains, Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14, have been the most studied for vaginal health. However, a controlled trial that gave participants oral probiotics containing these strains (at a billion or more colony-forming units per day for 30 days) alongside standard antibiotic treatment found that the probiotics did not increase the cure rate compared to antibiotics alone.
That doesn’t mean probiotics are useless for everyone. Some women report improvement with probiotic supplements or fermented foods, and the research is still evolving. But probiotics are not a reliable substitute for medical treatment when an active infection is present. Think of them as a possible supporting player, not the main fix.
When the Smell Is Probably Normal
Every vagina has a scent, and mild fluctuations are completely normal. Your smell can shift during your menstrual cycle, after exercise, during pregnancy, or with changes in diet. A slight metallic smell during or after your period is normal. A mild musky scent after a workout is normal.
What’s not normal is a strong, persistently fishy odor, especially if it comes with discharge that looks gray, green, or frothy, or with itching, burning, or irritation. Those signs point to an infection that won’t resolve on its own. BV sometimes clears without treatment, but it often comes back, and untreated BV can increase susceptibility to sexually transmitted infections. Getting it properly diagnosed and treated is the most reliable path to making the odor go away and stay away.