Boric Acid: A Technical Report

Boric acid, also known in scientific circles as boracic acid or orthoboric acid, is an inorganic acid chemical. Boric acid comes in several forms, the most common as a white powder. It is also available in granular, and crystalline forms. Actual boric acid vaginal suppositories available for purchase, have to be uniquely put together, and compounded by a pharmacy.

Boric Acid & Vaginal Infections

Boric acid has been a popular option for the treatment of vaginal infections for a period that spans more than 100 years.

Research studies suggest that boric acid contains antifungal and antiviral properties1. Boric acid has also been found to work effectively in targeting Candida albican species. Furthermore, some studies have also shown boric acid to be an effective option in the treatment of infections caused by Candida glabrata strains, a type of yeast that is often a concern due to resistance posed to many pharmaceutical products used in the treatment of yeast infections.

The vagina contains an acidic environment. A report indicates that vaginal acidification helps in destroying the cell wall and membrane of the fungus, thus allowing boric acid easy entrance into the fungus.  

A study2 by the Alfa Institute of Biomedical Sciences also found that boric acid is a very safe option. The researchers behind the study explain that the use of boric acid seems to be an effective protocol for women who have chronic symptoms related to vaginitis. Furthermore, the researchers found that boric acid should certainly be considered a treatment option where conventional pharmaceutical options fail to assist in the treatment of a vaginal yeast infection. Boric acid also seems to be highly effective among women who have recurrent vaginal infections. Clinical experience where boric acid was added to the standard treatment, for a triple phase maintenance regimen for women with recurrent bacterial vaginosis has been encouraging. Now researchers in Canada3 have an ongoing prospective randomized controlled study, which offers the full scientific validation (see below for more on the BASIC study).

boric acid crystalline

Boric Acid Pharmacokinetics


Many may wonder why boric acid capsules or tablets are not widely offered. To get a clear understanding of that, one needs an adequate explanation regarding the pharmacokinetics of boric acid. When a person takes boric acid orally, rapid absorption takes place.


Boric acid is then distributed around the body, building up in organs and tissues, notably the kidneys and the livers. Elimination of boric acid also seems to occur relatively quickly, and the product is not metabolized like other types of nutrients and products that can be consumed. Boric acid also builds up in the blood circulatory system of the human body, as well as soft tissue. While studies have confirmed that boric acid may also accumulate in the adipose tissue within rats, such results have not yet been identified in human subjects4.

Metabolism, and Excretion

Boric acid is broken down and mainly excreted unchanged by the kidneys. Within twelve hours, at least half of the amount taken is excreted, and 90% is usually excreted within four days. Vaginal administration of boric acid leads to a shorter half-life. A 600mg dose of boric acid through vaginal insertion has approximately 10.5 hours half life. Furthermore, 6% of the content seems to be absorbed into the body in such a case. The half-life of boric acid seems to be highest when administered intravenously, with studies reporting a half-life up to 21 hours.

Adverse Effects Associated With Boric Acid

The majority of studies that looked at the effects of boric acid have reported that the compound seems to be safe. It has been proven that boric acid is a compound that is well tolerated when administered through the vagina, often with the use of a capsule, known as a suppository that contains the boric acid compound.

In studies where side-effects have been reported, the adverse events are mostly mild and not of a concern. A watery discharge has been reported among some female patients who had used boric acid as a method for treating a vaginal yeast infection. There have also been cases where the patient reported a slight burning sensation in the vagina following the insertion of the boric acid capsule. Erythema is another mild side-effect that may occur in some cases.

It should be noted that some patients have reported complaints from their partner during sexual intercourse. The sensation experienced by the partner does not, however, seem to have any significant effects on either of the individuals who are involved in the activity. This particular type of side-effect tends to subside following the treatment period.

Even though the safety of boric acid as a treatment for vaginal yeast infection has been confirmed, it is important that patients do understand that the long-term results have not yet been reported. Thus, there is an urge for further studies on human subjects to determine the safety of using boric acid over a longer period of time. There have also been some reports regarding the possibility of toxicity upon topic exposure, as well as with the ingestion of boric acid. This is why the safety of boric acid may appear controversial in some studies and publications. Many of the top leading US medical institutions such as the University of Michigan, and Cleveland Clinic all mention the use of boric acid vaginal suppository for treating vaginal yeast infections. Currently there is an extensive ongoing clinical trial study, The BASIC (Boric Acid, Alternate Solution for Intravaginal Colonization) study5. It is the first prospective randomized control trial to determine the effectiveness of intravaginal boric acid compared with metronidazole for the treatment of bacterial vaginosis in symptomatic women. If intravaginal boric acid is shown to be non-inferior to metronidazole in the treatment of bacterial vaginosis, this may provide women with less costly options for treating this common vaginal infection. Overall, however, the use of the compound according to instructions provided by a healthcare provider may yield effective results for the patient, without significant side-effects.


Dr. Helen Okoye
Dr. Helen Okoye, M.D., M.B.A., M.S.-Epi
  1. F. De Seta, M. Schmidt, B. Vu, M. Essmann, B. Larsen. Antifungal mechanisms supporting boric acid therapy of Candida vaginitis. The Journal of Antimicrobial Chemotherapy. 4 Dec 2008.
  2. C. Iavazzo, I.D. Gkegkes, I.M. Zarkada, M.E. Falagas. Boric acid for recurrent vulvovaginal candidiasis: the clinical evidence. Journal of Women’s Health. 20 Jul 2011.
  3. Reichman, Orna & Akins, Robert & Sobel, Jack. (2009). Boric Acid Addition to Suppressive Antimicrobial Therapy for Recurrent Bacterial Vaginosis. Sexually transmitted diseases. 36. 732-4. 10.1097/OLQ.0b013e3181b08456.
  4. F.J. Murray. A comparative review of the pharmacokinetics of boric acid in rodents and humans. Journal of Biological Trace Element Research. 1998.
  5. Zeron Mullins, M., & Trouton, K. M. (2015). BASIC study: is intravaginal boric acid non-inferior to metronidazole in symptomatic bacterial vaginosis? Study protocol for a randomized controlled trial. Trials, 16, 315. doi:10.1186/s13063-015-0852-5