For a straightforward yeast infection, Diflucan (fluconazole) is taken as a single 150 mg dose. One pill, one time. Most people start feeling relief within a few days, though the medication stays active in vaginal tissue for up to 72 hours after that single dose thanks to a long half-life of about 34 hours.
That said, dosing gets more involved if your infection is severe or keeps coming back. Here’s how the schedule changes depending on your situation.
One Dose for Uncomplicated Infections
The standard treatment for a typical vaginal yeast infection is a single 150 mg oral dose. You swallow one capsule and you’re done. The drug concentrates well in vaginal tissue, reaching levels nearly equal to what’s circulating in your blood for the first 48 hours. It remains detectable in vaginal fluid for at least 72 hours. This is why a single pill can clear an infection that a topical cream might take a full week to treat.
Most people notice itching and discharge improving within two to three days. If symptoms haven’t improved at all after three days, or they come back within a couple of months, the infection may need a different approach.
Three Doses for Recurrent Infections
If you get four or more yeast infections in a year, you fall into the “recurrent” category, and a single pill won’t cut it. The CDC recommends an induction phase: one dose of fluconazole every third day for three total doses, taken on days 1, 4, and 7. This extended initial treatment aims to fully eliminate the yeast rather than just knocking it back temporarily.
After that induction phase, you move into maintenance therapy: one dose per week for six months. This weekly schedule suppresses the yeast long enough for the vaginal environment to stabilize. The six-month timeline matters. Stopping earlier often leads to another recurrence because the underlying tendency for overgrowth hasn’t been fully controlled.
To summarize the full recurrent schedule:
- Days 1, 4, and 7: One dose every third day (three doses total)
- Weeks 2 through 26: One dose per week for six months
Why Severe Infections May Need a Second Dose
A yeast infection counts as severe when you have significant redness, swelling, or cracking of the skin around the vulva, not just the usual itching and discharge. For these cases, a single dose often isn’t enough to bring symptoms under control. The typical approach is two doses of 150 mg taken 72 hours apart (day 1 and day 4), giving the medication more time at therapeutic levels in the tissue.
Some providers extend this to the same three-dose schedule used for recurrent infections, especially if the symptoms are particularly intense. The key difference is that severe one-off infections don’t usually require the six-month maintenance phase afterward.
When the Yeast Species Matters
Most vaginal yeast infections are caused by Candida albicans, which responds well to fluconazole at standard doses. But roughly 10 to 20 percent of infections involve other species that are naturally less sensitive to the drug. If your infection doesn’t clear after a standard course, or if a culture identifies a resistant species, the treatment approach changes significantly. Higher doses, longer courses, or entirely different antifungal medications may be needed. A single 150 mg dose won’t work reliably in these situations.
How Long Until Symptoms Improve
Because fluconazole works by disrupting the cell membranes of the yeast (essentially preventing them from growing and reproducing), it doesn’t kill every organism instantly. After taking the pill, expect gradual improvement over two to three days. Itching usually eases first, followed by a reduction in discharge. Some mild symptoms can linger for up to a week as the remaining yeast dies off and the irritated tissue heals.
If you’re on the three-dose induction schedule, most people feel significantly better by the second or third dose. The maintenance phase that follows isn’t about treating active symptoms. It’s preventive, keeping yeast counts low enough that a new infection doesn’t take hold.
Side Effects to Expect
Fluconazole is generally well tolerated at the 150 mg dose. The most commonly reported issues are nausea, headache, and mild stomach discomfort. These tend to be short-lived, resolving within a day. Serious side effects are rare with a single dose but become more relevant during long-term weekly use, where liver function can occasionally be affected.
One important safety consideration: fluconazole interacts with several medications by slowing down how your body processes them. This can lead to dangerously high levels of certain drugs in your bloodstream, particularly those that affect heart rhythm. If you take any prescription medications regularly, make sure your provider knows before starting fluconazole, especially for a longer maintenance course.
Taking It With or Without Food
Fluconazole absorbs well regardless of whether you take it on an empty stomach or with a meal. If you’re prone to nausea, taking it with food can help. The timing of day doesn’t matter either. For the every-third-day induction schedule, spacing your doses as close to 72 hours apart as practical gives the most consistent drug levels, but being off by a few hours won’t undermine the treatment.