Baking soda, also known as sodium bicarbonate or NaHCO3, is a common household product made of sodium, hydrogen, carbon, and oxygen. People use baking soda on a daily basis in toothpaste, for cleaning, baking, odor control, and sometimes even as an antacid.
Many people talk about trying baking soda as an acne treatment online as well. When used as an acne treatment, baking soda is mixed with water to create a paste that is briefly applied onto the acne-affected area and then washed off.1However, any effect baking soda may have on acne is purely anecdotal since scientists have not studied the effect of baking soda on acne. Therefore, we must rely on studies investigating the various properties of baking soda and try to infer how these properties may impact acne. As we will see, while baking soda may have weak antibacterial properties, as a whole, the evidence shows us that baking soda should most likely be avoided for people who are acne-prone.2-3
The three most commonly studied characteristics of baking soda are:
- Its antibacterial effect
- Its exfoliating properties
- Its alkaline nature
Let's have a closer look at these properties of baking soda and how they relate to acne.
The Properties of Baking Soda
Antibacterial Effect: Acne is a disease that is made worse by the bacteria P. acnes. There are no studies to evaluate whether baking soda has antibacterial effects on P. acnes. However, studies evaluating baking soda in toothpaste have demonstrated that baking soda has antibacterial properties against the bacterium S. mutans, which is a bacterium of similar class and characteristics as P. acnes. A 2005 study published in the Journal of Dental Hygiene investigated the antibacterial effects of baking soda on a bacterium called Streptococcus mutans (S. mutans) and found that it could not kill the bacteria but may stop its growth.
To perform this study, the researchers grew S. mutans in a laboratory and exposed the bacteria to either baking soda or hydrogen peroxide. The study found that baking soda prevented S. mutans growth, while hydrogen peroxide killed S. mutans. Therefore, the scientists concluded that baking soda has the ability to inhibit bacterial growth.
Most individuals with acne have an overgrowth of Propionibacterium acnes (P. acnes) bacteria in their skin. Although not directly studied in this experiment, it is possible that baking soda may also inhibit the growth of P. acnes bacteria. So, in a best-case scenario, would baking soda just halt the growth of P. acnes, and if so, would that help lessen acne symptoms? Perhaps to a limited degree. However, scientists will need to perform more studies to confirm this hypothesis.3
Exfoliating Agent: Baking soda acts as an abrasive, which means that it is able to remove substances that are stuck on a surface. In toothpaste, the abrasive nature of baking soda is used to remove plaque buildup on teeth. When used on the skin, the abrasive quality of baking soda acts as an exfoliating agent to remove dead skin cells. Acne is formed through the accumulation of substances, including dead skin cells, in the pores. Theoretically, if you exfoliate the surface of the skin in a non-irritating way this can signal the skin underneath to produce cells more quickly, which can help prevent clogs.3,4
However, the key is to exfoliate in a non-irritating way. When it comes to baking soda, its abrasive quality means it is potentially irritating to the skin. It is well-known that anything that irritates the skin can cause more acne. Therefore, exfoliating the skin with baking soda could cause irritation and potentially make breakouts worse. Instead of physically exfoliating with an abrasive like baking soda, it is far more effective to exfoliate chemically with an acid, like glycolic acid, which is non-irritating and has been proven to help with acne.
Alkaline Nature: Baking soda is alkaline. When used on the skin, baking soda may make the skin more alkaline, or "basic." Some skin care bloggers suggest that using alkaline skin products will make the skin healthier. However, facial skin’s natural pH is approximately 5.25, which is slightly acidic. For ideal skin health, and prevention of acne, the pH should be left unchanged. Since using baking soda on the skin can raise its pH, this is likely a bad idea when it comes to acne.
While baking soda's antibacterial properties might prove to be beneficial for acne, care must be taken when applying it to the skin. Baking soda's natural abrasive quality could irritate the skin and its alkalinity may increase the pH of the skin, both of which could lead to further breakouts.
Bottom line: Look for other proven methods of combatting acne. Baking soda is at best a weak antibacterial agent and at worst can cause more breakouts through physical irritation and unnecessarily raising the pH of the skin.