Boric acid may help with some yeast infections, but it is usually not the first treatment to try. It is mainly used for yeast infections that keep coming back or do not improve with the usual antifungal medicines.
Boric acid is placed inside the vagina as a suppository. It should never be taken by mouth, because swallowing it can be dangerous. It may also cause vaginal burning, irritation, or discomfort in some people.
You should not use boric acid if you are pregnant, trying to get pregnant, or think you might be pregnant unless a healthcare professional specifically tells you to. It is also important to make sure your symptoms are really from a yeast infection, since itching, burning, and discharge can also happen with other vaginal infections.
If this is your first yeast infection, your symptoms are severe, or the infection keeps coming back, it is best to see a gynecologist or another healthcare professional. Avoid self-treating repeatedly, because the wrong treatment can delay proper care.