A garlic-like smell from your genital area usually comes from one of two sources: something you recently ate, or bacteria on your skin breaking down sweat into sulfur-containing compounds. Less commonly, it can signal an infection or a pH imbalance. The good news is that most causes are harmless and temporary.
Diet Is the Most Common Cause
Garlic contains sulfur compounds that your body can’t fully break down during digestion. Instead, they get absorbed into your bloodstream and exit through sweat, urine, and mucosal secretions, including vaginal discharge. One study measuring skin emissions after participants ate 45 grams of cooked garlic found that the sulfur compound diallyl disulfide was still being released through the skin eight hours later, and the effect can persist for up to two days. Onions, cruciferous vegetables like broccoli and cabbage, and heavily spiced foods can produce a similar effect.
Because the groin is warm and enclosed, these odors tend to concentrate there more than on other parts of your body. If you ate garlic or onions in the last 24 to 48 hours, that’s very likely your answer, and the smell will fade on its own.
Sweat and Bacteria Working Together
Your groin has a high density of apocrine sweat glands, the type that produces thicker, protein-rich sweat. This sweat is odorless on its own, but skin bacteria (primarily Staphylococcus species) feed on it and produce byproducts that smell. Some of these byproducts are sulfur-based compounds, which can register as garlicky, oniony, or just generally pungent. The warmer and more moist the area, the more bacteria thrive and the stronger the smell gets.
Exercise, tight clothing, sitting for long periods, and hot weather all increase sweat production and create the conditions for stronger odor. This is normal body chemistry, not a sign of poor hygiene or illness.
Your Underwear Might Be Making It Worse
Synthetic fabrics like polyester and nylon trap odor-causing bacteria at the fiber level. Research published in Applied and Environmental Microbiology found that synthetic fabrics retain roughly ten times more bacteria than natural fibers, even after multiple washes. Odor-causing bacteria were found almost exclusively on synthetic materials in the study. Cotton and merino wool, by contrast, create a less hospitable environment for bacterial growth. Switching to breathable, natural-fiber underwear can make a noticeable difference in how much odor builds up throughout the day.
Infections That Affect Vaginal Odor
If you have a vagina, a persistent unusual smell can sometimes point to an infection, though the classic odor associated with the most common one, bacterial vaginosis (BV), is typically described as fishy rather than garlicky. BV happens when the balance of bacteria in the vagina shifts, allowing anaerobic bacteria to overgrow and produce compounds like trimethylamine, putrescine, and cadaverine. A healthy vaginal pH sits between 3.8 and 4.5, and BV pushes it above 4.5.
That said, people describe smells differently, and what one person calls “garlicky” another might call “fishy” or just “off.” If the smell is accompanied by a grayish-white discharge, itching, burning, or has persisted for several days without a dietary explanation, an infection is worth considering. A retained tampon or other forgotten foreign body can also cause a strong, foul odor that worsens over time.
Yeast infections, interestingly, don’t usually change vaginal pH or produce a strong odor. Their hallmark is thick, white discharge and itching rather than smell.
How to Reduce the Smell
If diet is the culprit, the simplest fix is time. Your body will clear the sulfur compounds within one to two days. Drinking more water can help speed things along by diluting the concentration in your sweat and urine.
For sweat-related odor, focus on keeping the area dry and reducing bacterial buildup:
- Wear breathable fabrics. Cotton or merino wool underwear allows airflow and harbors far fewer odor-producing bacteria than synthetics.
- Change underwear after sweating. Sitting in damp clothing gives bacteria hours to multiply.
- Wash with warm water and mild soap. The external genital area benefits from gentle daily cleansing, but avoid douches or fragranced products inside the vagina, which can disrupt the natural bacterial balance and make odor problems worse.
If you suspect a bacterial imbalance, probiotics containing Lactobacillus strains may help. A randomized, double-blind trial found that both oral and vaginal probiotic capsules containing Lactobacillus crispatus significantly improved BV symptoms, including discharge and irritation, over three months. Probiotics work by replenishing the beneficial bacteria that keep vaginal pH in its healthy acidic range. They’re available over the counter, though for confirmed BV, antibiotics prescribed by a clinician are the standard first-line treatment.
When the Smell Signals Something More
An unfamiliar odor that lasts more than a few days, especially paired with unusual discharge, itching, burning, or pelvic discomfort, warrants a medical visit. These combinations often point to BV, trichomoniasis, or another treatable condition. If you’re pregnant and noticing a persistent change in vaginal odor, it’s particularly important to get evaluated, as vaginal infections during pregnancy carry a higher risk of complications including preterm birth.
For most people, though, a garlic-like smell that shows up and fades within a day or two is just your body processing what you ate, amplified by the warm, enclosed environment of your groin. It’s one of the more predictable quirks of human biology.