Vaginal yeast infections are driven by an overgrowth of Candida fungus that naturally lives in the vagina, and preventing them comes down to keeping that fungus in check. The strategies that work target the conditions yeast needs to thrive: warmth, moisture, excess sugar, and a disrupted microbial balance. Most are simple daily habits, though people with recurring infections may need more targeted approaches.
Keep the Area Dry and Breathable
Yeast thrives in warm, moist environments. Cotton underwear is the single best fabric choice because it wicks away sweat and moisture rather than trapping it against your skin. The Cleveland Clinic specifically recommends 100% cotton for anyone dealing with recurrent vaginal or vulvar issues, noting that synthetic underwear with a small cotton crotch panel doesn’t offer the same protection because the surrounding synthetic material still traps heat.
The same logic applies to wet swimsuits and sweaty workout clothes. Change into dry clothing right after your last swim or after exercising. Sitting in damp fabric for hours creates exactly the kind of environment Candida loves. Tight-fitting pants and pantyhose can also reduce airflow, so looser clothing helps when you’re prone to infections.
Skip the Douching
Your vagina maintains its own ecosystem, dominated by beneficial Lactobacillus bacteria that produce lactic acid and keep the pH low enough to suppress yeast and harmful bacteria. Douching disrupts this system. Research published in the American Journal of Obstetrics and Gynecology found that douching at least once a month more than doubled the risk of abnormal vaginal flora when done within a week of testing. The mechanism is straightforward: flushing the vaginal canal strips away the protective bacteria, giving opportunistic organisms room to multiply.
Scented soaps, sprays, and bubble baths can cause similar disruption. Warm water on the external area is sufficient for hygiene. If you use soap, stick to unscented, mild formulas and keep it on the outside only.
Watch Your Blood Sugar
Yeast feeds on sugar, and research shows this connection is more than theoretical. A study comparing women with recurrent yeast infections to those without found that the recurrent group had notably higher blood glucose levels at every point during a glucose tolerance test, even though they weren’t diabetic. Their fasting glucose was higher (89 vs. 85 mg/dL), and the gap widened after consuming sugar, with levels at the 60-minute mark reaching 123 mg/dL compared to 102 in controls. Their glycosylated hemoglobin, a marker of average blood sugar over time, was 25% higher.
The researchers concluded that even glucose concentrations within the normal range can be substantially higher in women with recurrent infections, suggesting that a diet high in refined sugars could contribute to risk. You don’t need to eliminate sugar entirely, but cutting back on sugary drinks, white bread, and processed sweets may make a meaningful difference if you’re getting frequent infections. This is especially relevant if you carry extra weight, since the study also found that women with recurrent infections had a higher average BMI.
Understand Hormonal Risk Factors
Estrogen increases glycogen in the vaginal lining. Under normal circumstances, Lactobacillus bacteria convert that glycogen into lactic acid, maintaining an acidic environment that keeps yeast in check. But when estrogen levels spike, as during pregnancy, with certain hormonal contraceptives, or during hormone replacement therapy, the extra glycogen can tip the balance in favor of Candida colonization.
If you notice a pattern of yeast infections tied to your birth control, it’s worth discussing alternatives with your prescriber. Pregnancy-related infections are harder to avoid, but knowing the connection helps you stay alert to early symptoms so you can treat them before they worsen.
Be Strategic During and After Antibiotics
Antibiotics kill bacteria indiscriminately, including the Lactobacillus that protect against yeast overgrowth. This is one of the most common triggers for yeast infections. The CDC notes that antibiotics and corticosteroids both increase the risk of candidiasis and recommends telling your provider if symptoms develop during a course of treatment.
If you know from experience that antibiotics give you a yeast infection, mention it before starting a prescription. Some providers will prescribe a single dose of antifungal medication to take alongside or immediately after the antibiotic course. Taking a probiotic during antibiotic treatment may also help, though timing matters: space the probiotic at least two hours away from your antibiotic dose so the antibiotic doesn’t immediately kill the probiotic bacteria.
Consider Targeted Probiotics
Not all probiotics are equally useful for vaginal health. The most studied combination for maintaining healthy vaginal flora is Lactobacillus rhamnosus GR-1 paired with Lactobacillus reuteri RC-14, taken orally. In one clinical trial, women who took this combination daily alongside standard antibiotic treatment had normal vaginal flora 88% of the time at 30 days, compared to just 40% in the group taking antibiotics with a placebo. A second trial showed similar results: 85% of the probiotic group had normal flora at 28 days versus 50% in the placebo group.
The effective dose in these studies was about 2.5 billion colony-forming units of each strain per capsule, taken once or twice daily. These strains work by colonizing the vaginal tract (even when taken by mouth) and restoring the Lactobacillus-dominant environment that resists yeast overgrowth. Look for products that specifically list these strains on the label. A general “women’s probiotic” without strain-level information may not deliver the same benefit.
Hygiene Around Sex
Sexual activity can introduce bacteria or irritants that shift vaginal pH. A few practical habits reduce the risk. If a finger, toy, or penis has contact with the anus, it needs to be washed thoroughly or covered with a fresh condom before touching the vagina. Bacteria from the digestive tract can disrupt vaginal flora quickly. Clean sex toys carefully between uses according to their specific instructions, since porous materials can harbor yeast.
Some lubricants and spermicides cause irritation that makes the vaginal lining more vulnerable to infection. If you notice symptoms after using a particular product, switch brands or opt for a water-based, fragrance-free formula. Urinating after sex helps flush bacteria from the urethra (more relevant for UTI prevention), but it doesn’t hurt your yeast prevention efforts either.
Boric Acid for Recurring Infections
For people dealing with chronic yeast infections that keep coming back despite standard treatment, boric acid vaginal suppositories are a well-established maintenance option. UW Medicine’s protocol recommends that after completing treatment for an active infection, you insert a boric acid capsule vaginally two nights per week (spaced a few days apart, such as Monday and Thursday) for 6 to 12 months.
You can purchase premade suppositories or make your own using boric acid powder (not crystals) packed into size “0” gelatin capsules. Boric acid works by creating an environment hostile to Candida without disrupting the beneficial bacteria. It is for vaginal use only and should never be taken by mouth. This approach is typically reserved for recurrent cases and is best discussed with a provider to confirm the diagnosis and rule out other causes.
Putting It All Together
Prevention works best as a combination of habits rather than any single fix. Wearing cotton underwear, changing out of wet clothes promptly, and avoiding douching maintain the baseline environment your vaginal flora needs. Limiting refined sugar and managing blood sugar help starve yeast of its preferred fuel. Probiotics with clinically studied strains rebuild protective bacteria, especially after antibiotics. And for people with stubborn recurrent infections, boric acid maintenance can break the cycle when everyday measures aren’t enough.