Benefits of Soaking in Baking Soda: What the Research Shows

Baking soda — sodium bicarbonate — is one of the most common household compounds, and for generations people have used it in baths and foot soaks for a variety of reasons. But what does the science actually say about soaking in it, and who might respond differently than others?

What Baking Soda Actually Is

Sodium bicarbonate (NaHCO₃) is an alkaline salt — a compound that raises pH when dissolved in water. In chemistry terms, it acts as a buffer, meaning it resists rapid changes in acidity. When you dissolve it in bathwater, it shifts the water's pH from the slightly acidic range toward the alkaline side.

That shift in pH is the basis for most of the proposed benefits of baking soda soaks. The skin's surface normally maintains a slightly acidic pH (roughly 4.5–5.5), which supports the skin barrier and the microbial balance on its surface. Changing that environment — even temporarily — can have real physiological effects, which is why this is worth understanding carefully rather than casually.

What Research Generally Shows About Baking Soda Soaks

Skin Irritation and Itching 🧴

Some dermatology literature and clinical guidance references dilute sodium bicarbonate baths as a soothing measure for certain types of itching and skin discomfort. The proposed mechanism is that raising the bath water's pH may temporarily calm irritation associated with conditions where the skin's acid environment has been disrupted.

However, evidence here is largely observational and practice-based rather than drawn from large clinical trials. The research is limited and mixed — some dermatologists note that alkaline solutions can also disrupt the skin barrier with repeated use, particularly in people with sensitive or compromised skin.

Foot Soaks and Odor

Baking soda foot soaks are commonly recommended in folk remedy contexts for foot odor and minor skin softening. The rationale is that bacteria responsible for foot odor produce acidic byproducts, and an alkaline environment may temporarily suppress their activity. This mechanism is plausible in principle, but robust clinical evidence specifically supporting baking soda foot soaks is sparse.

Muscle Soreness — A Nuance Worth Understanding

There is a body of research — mostly in athletic performance contexts — examining oral sodium bicarbonate supplementation and its effects on buffering lactic acid during intense exercise. This is an internal, metabolic application and is chemically distinct from external soaking. The benefits seen in those studies do not translate directly to topical baths.

Epsom salt (magnesium sulfate) baths are more commonly studied in the context of muscle soreness. Baking soda baths are sometimes paired with Epsom salts in wellness contexts, but the contributions of each component in combined soaks haven't been well separated in research.

Skin pH and Conditions Like Eczema

Some research on eczema (atopic dermatitis) points to skin barrier disruption and elevated skin pH as factors in the condition's flares. A few small studies have looked at dilute sodium bicarbonate baths — noting some short-term symptom relief in certain patients — but larger, well-controlled trials are lacking. Importantly, other research cautions that overly alkaline solutions may worsen barrier function over time. This area remains a genuine mixed picture in the literature.

Variables That Shape How People Respond

The effects of a baking soda soak are not uniform. Several factors meaningfully influence outcomes:

Where Individual Responses Diverge

A person with intact, healthy skin who uses a dilute baking soda soak occasionally is in a very different position than someone managing a chronic skin condition, taking diuretics, monitoring blood pressure, or dealing with open wounds or infections. For some people, anecdotal relief from itching or skin discomfort is real and consistent. For others, the same soak may aggravate skin sensitivity or dryness — particularly with frequent use.

The sodium component also matters in a different way: while transdermal sodium absorption from a bath is not equivalent to ingesting sodium, people with certain health conditions are sometimes advised to be mindful of all potential sodium exposures. The clinical significance of bathing sodium is not well established, but it's a variable some healthcare providers consider.

The Piece Only You Can Provide

The research gives a framework — alkalinity, skin pH, limited but real evidence for some uses, and meaningful caution around barrier disruption and individual sensitivities. What the research can't tell you is how your skin specifically responds, what your current health status means for this kind of exposure, or how it fits with anything else you're managing. That part of the picture depends entirely on information about your own health that no general article can account for.