Several common medications can trigger yeast infections, with antibiotics being the most frequent culprit. Hormonal birth control, steroids, diabetes drugs, and chemotherapy treatments also carry meaningful risk. In each case, the medication either disrupts the natural balance of bacteria and yeast in your body or weakens the immune defenses that normally keep yeast in check.
Antibiotics Are the Most Common Cause
Broad-spectrum antibiotics are the number one medication-related cause of yeast infections. These drugs are designed to kill a wide range of bacteria, but they don’t distinguish between harmful bacteria and the beneficial ones your body relies on. In the vagina, bacteria called lactobacillus normally keep yeast populations small. When antibiotics wipe out those protective bacteria, yeast (most often a species called Candida) multiplies unchecked.
The broader the antibiotic, the higher the risk. Penicillins, cephalosporins, and fluoroquinolones are among the most commonly prescribed broad-spectrum options, and all of them can set the stage for yeast overgrowth. Narrow-spectrum antibiotics, which target a smaller range of bacteria, are less likely to cause problems because they leave more of the protective bacteria intact. Longer courses of antibiotics also increase the risk, since the beneficial bacteria have less chance to recover.
Symptoms often appear during the antibiotic course or shortly after finishing it. If you’ve had yeast infections after antibiotics before, that pattern is likely to repeat with future courses. The CDC notes that frequent antibiotic use is a recognized cause of recurrent yeast infections, defined as three or more episodes in a single year.
Hormonal Birth Control
Combination birth control methods that contain both estrogen and progestin can shift the hormonal environment in ways that favor yeast growth. This includes many birth control pills, the patch, and the vaginal ring. These methods alter your body’s natural balance of estrogen and progesterone, and Candida yeast can bind to estrogen in a way that disrupts how your body uses it. The resulting hormonal shift creates conditions where yeast and certain bacteria flourish more easily.
Not everyone on hormonal birth control will experience this. The risk tends to be higher with formulations that contain more estrogen. If you notice a pattern of yeast infections that started after beginning a new contraceptive, switching to a lower-estrogen option or a non-hormonal method like a copper IUD may help break the cycle.
Corticosteroids and Steroid Inhalers
Corticosteroids suppress your immune system, which is exactly why they’re prescribed for conditions like asthma, autoimmune diseases, and severe allergies. But that same immune suppression makes it harder for your body to keep Candida in check. Oral steroids like prednisone can increase the risk of yeast infections throughout the body, including vaginal and oral infections.
Inhaled corticosteroids used for asthma and COPD pose a more specific risk: oral thrush, a yeast infection of the mouth and throat. A large meta-analysis found that people using inhaled steroids had 3.6 times the risk of developing oral thrush compared to those on a placebo, and the risk increased with higher doses. Certain inhaler types carried even greater risk. Rinsing your mouth with water and spitting after each use significantly reduces the chance of developing thrush, and most pulmonologists recommend this as a standard practice.
The mechanism is straightforward. When steroid particles deposit on the lining of your mouth and throat, they suppress the local immune response on those surfaces. Even though the medication is intended for the lungs, enough of it contacts the upper airway to create an environment where yeast can take hold.
SGLT2 Inhibitors for Diabetes
A class of diabetes medications called SGLT2 inhibitors carries a well-documented risk of genital yeast infections. These drugs work by causing your kidneys to excrete excess sugar through urine. The problem is that sugar-rich urine passing through the genital area creates an ideal feeding ground for yeast.
An estimated 5 to 10% of people taking SGLT2 inhibitors develop genital yeast infections. The risk is higher in premenopausal women, people with a history of yeast or urinary tract infections, and those who are obese. Common SGLT2 inhibitors include canagliflozin, dapagliflozin, and empagliflozin. If your doctor has recently started you on one of these medications and you develop recurrent infections, it’s worth discussing whether the benefits still outweigh the side effects or whether an alternative diabetes drug would work for you.
Chemotherapy and Immunosuppressants
Cancer treatments carry some of the highest risks for yeast infections, though the context is very different from everyday antibiotic use. Chemotherapy damages the mucous membranes lining the mouth, throat, and digestive tract, creating openings where yeast can establish itself. At the same time, chemo often causes neutropenia, a drop in the white blood cells that serve as your body’s front-line defense against fungal infections. Neutropenia is considered the single most important factor in why cancer patients develop serious Candida infections.
The risk compounds further because cancer patients frequently receive broad-spectrum antibiotics to prevent bacterial infections during treatment, and they may also be on corticosteroids. Each of these medications independently raises the risk of yeast overgrowth, and together they create conditions where infections are common. Oncology teams typically monitor for signs of fungal infection and may prescribe preventive antifungal medication during high-risk treatment phases.
Other Medications That Raise Risk
Beyond the major categories, a few other medications deserve mention. Immunosuppressants prescribed after organ transplants or for autoimmune conditions (like those used for lupus, rheumatoid arthritis, or inflammatory bowel disease) weaken the same immune pathways that keep yeast under control. The higher the degree of immune suppression, the greater the risk.
Hormone replacement therapy used during menopause can also contribute, particularly estrogen-based formulations, through the same mechanism as hormonal birth control. And any medication that causes dry mouth as a side effect (including certain antidepressants, antihistamines, and blood pressure drugs) can increase the risk of oral thrush specifically, since saliva plays a protective role against yeast in the mouth.
Reducing Your Risk While on These Medications
If you’re on a medication known to trigger yeast infections, there are practical steps that can lower your chances. For inhaled steroids, rinsing and spitting after every dose is the simplest and most effective prevention. For antibiotics, eating foods with live active cultures like yogurt or kefir is a common strategy, though the CDC notes there isn’t strong evidence that probiotics treat active yeast infections. Wearing breathable cotton underwear, avoiding prolonged time in wet clothing, and keeping the genital area dry all reduce the warm, moist conditions yeast thrives in.
If you experience three or more yeast infections in a year and you’re on one of the medications listed above, that pattern may qualify as recurrent vulvovaginal candidiasis. Treatment for recurrent infections typically involves a longer course of antifungal medication, sometimes taken weekly for six months, to suppress the yeast while your body’s balance is restored. These maintenance regimens are effective at controlling symptoms but rarely eliminate the problem permanently if the underlying medication continues.
The most important thing to recognize is the connection between your medication and the infection. Many people treat repeated yeast infections without realizing the drug they’re taking is the root cause. Identifying that link gives you and your healthcare provider the chance to adjust the medication, add a preventive strategy, or at least set realistic expectations about managing symptoms going forward.