Several scientific studies have examined the health benefits of baking soda and lemon juice separately, but there is not much research to support the combined effects of these two ingredients.

This article discusses some of the potential health benefits of consuming baking soda and lemon juice mixtures.
<h3>A note about pH</h3>
The idea of combining baking soda and lemon juice draws on basic principles of acidity and the pH scale.

Scientists use the pH scale to measure the acidity of a solution. A solution can have a pH level between 0 and 14.

The lower the pH, the more acidic the solution, so:
<ul>
 	<li>pH levels below 7 indicate an acidic solution</li>
 	<li>pH levels above 7 indicate an alkaline, or base solution</li>
 	<li>neutral solutions, such as pure water, have a pH of 7</li>
</ul>
Baking soda, also known as sodium bicarbonate, is a base. This means that when people dissolve baking soda in water, it forms an alkaline solution. For example, a 0.1 molar solution of baking soda has a pH of around 8.3.

Lemon juice contains citric acid and has a pH of around 3. Adding baking soda to lemon juice will raise the pH to produce a more neutral solution.
<h3>Skin care</h3>
Usually, the skin has a weakly acidic pH of about 5.7. Bases, such as baking soda, will increase the pH of the skin. Higher pH levels can disrupt the barrier function of the skin, which may lead to dryness, excess oil production, and acne.

Lemon juice appears to have obvious skincare applications because it contains concentrations of vitamin C and citric acid, which both provide powerful skin benefits. Citric acid is an alpha-hydroxy acid (AHA) that manufacturers commonly use in chemical peels.

However, skin cells naturally repel water-soluble molecules, such as vitamin C. This means that very little vitamin C will actually penetrate the skin.

The high acid content of lemon juice can lower the pH level of the skin. Low pH levels may cause skin irritation, hyperpigmentation, and UV light sensitivity.

<strong>Alternatives</strong>

Using a homemade mixture of baking soda and lemon juice may potentially be harmful to the skin. Instead, a person can try using neutral cleansers or chemical peels that contain AHAs, such as glycolic acid.
<h3>Neutralizing stomach acid</h3>
Excess stomach acid can cause uncomfortable symptoms, such as heartburn, vomiting, and indigestion.

Many people with excess stomach acid take over-the-counter (OTC) antacids to relieve their symptoms. Consuming baking soda and lemon juice together may also neutralize stomach acid in a similar fashion as an antacid.

A 2017 study examined the antacid effects of various foods. The authors of this study created artificial stomach acid with a pH of 1.2. Although lemon juice by itself had almost no effect, sodium bicarbonate successfully neutralized the synthetic stomach acid.

Many OTC antacids contain sodium bicarbonate and citric acid. Lemons and other citrus fruits are rich sources of naturally-occurring citric acid.

When a person mixes lemon juice and baking soda, the citric acid reacts with the sodium bicarbonate to produce a buffer called sodium citrate. A buffer refers to a weak acid or base that prevents drastic pH changes. Although lemon juice does not neutralize stomach acid, it may help stabilize the pH level inside the stomach.

<strong>Alternatives</strong>

Using baking soda and lemon juice to combat excess stomach acid may be a good home remedy, as effective OTC antacids contain similar ingredients.

However, mixing the correct proportions of baking soda and lemon juice can be difficult.

Consuming a mixture with too much baking soda may cause diarrhea and gas, whereas too much lemon juice could trigger acid reflux and make symptoms worse. Purchasing an antacid at the drug store is often much safer.

Other home remedies for reducing excess stomach acid include:
<ul>
 	<li>avoiding or reducing acidic foods and beverages</li>
 	<li>limiting caffeine intake</li>
 	<li>limiting alcohol consumption</li>
 	<li>eating smaller meals</li>
 	<li>drinking more water</li>
 	<li>getting enough sleep</li>
</ul>
People with severe or persistent acid reflux or heartburn should speak to a doctor or gastroenterologist.