Potassium Hydroxide- Why Is Potassium Hydroxide Used? And Do You Need To Be Careful With This Ingredient?



What Is Potassium Hydroxide?

Potassium hydroxide is a highly alkaline ingredient that is used in small amounts in cosmetics and skincare products to stabilize the pH of a product.

If you’re researching potassium hydroxid, you might be looking for clean yet effective skincare. One brand we recommend is Carrot & Stick. You can read more about this brand at the bottom of the article.

Potassium hydroxide, also known as lye and caustic potash, is an inorganic compound. Potassium hydroxide is mainly used in soap and some cleansers for the saponification of oils. Potassium hydroxide is also used in the manufacture of pulp and paper, textiles, soaps and detergents, and as a drain cleaner. While the idea of having an ingredient that is used in drain cleaner in your soap may be scary, potassium hydroxide is completely used up during the saponification process and isn’t present in the final product.

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Potassium Hydroxide Ingredient Review


Potassium Hydroxide

the good: Helps to stabilize the pH of the skincare products and is used in the saponification of oils to create soaps and detergents.

the not so good: Can be harsh in higher concentrations, causing irritation and sensitivity.

Who is it for? All skin types except those that have an identified allergy to it.

Synergetic ingredients: Works well with most ingredients.

Keep an eye on: Keep an eye out for more research into other uses of potassium hydroxide.

What Is The Function Of Potassium Hydroxide?

Potassium hydroxide is noteworthy as the precursor to most soft and liquid soaps, but can also be used in the formulation of bath products, cleansing products, fragrances, foot powders, hair dyes and colors, makeup, nail products, personal cleanliness products, shampoos, shaving products, and skincare products.



The main function of potassium hydroxide in cosmetics and skincare products is to stabilize the pH of a product. The pH of products is an important component of skincare formulations. If the pH of a product is too acidic or too basic the product can disrupt the delicate skin mantle barrier. The skin’s normal pH is slightly acidic typically between 4.5-5.75. This acidity of the skin is termed the “acid mantle” and is maintained by sebaceous glands, sweat glands, and normal skin flora. The acid mantle provides a film of amino and lactic acids and oils that effectively protect skin from environmental factors such as bacteria, pollutants, and allergens. Damage to the skin mantle barrier can contribute to premature aging, sensitivity, and irritation.

It is important to regulate the pH of cosmetics and personal care products so as not to shift the skin’s normal pH too far from normal. On one hand, if a product is too acidic it may irritate the skin or cause a stinging sensation. On the other hand, a product that is too alkaline is detrimental because it depletes the skin of vital, natural lipids. Additionally, a disrupted acid mantle will not allow for products to absorb into the skin as well. This is why pH adjusters like potassium hydroxide are used in cosmetic formulations.

What Are The Issues With Potassium Hydroxide?

In high concentrations, potassium hydroxide can aggravate skin, even if used in rinse-off products such as soaps or cleansers. In fact, a study on skin products found that using an alkaline cleanser, even once, can do significant damage to the skin. Alkaline cleansers alter the skin’s natural bacterial flora composition and the activity of the enzymes in the upper layers of skin since these both have an optimal pH level. Furthermore, the damage is cumulative: the longer you use the product, the more damage it does to your skin.

Is Potassium Hydroxide Safe?

Potassium hydroxide is considered to be safe for its indicated use in skincare and cosmetic formulations. The US Food and Drug Administration classifies it as GRAS or Generally Recognized as Safe as a direct food additive.

Concentrated potassium hydroxide is a strong irritant and corrosive to the skin, eyes, respiratory tract, and gastrointestinal system if ingested. The severity of effects caused by potassium hydroxide is dependent on the concentration, the pH, the length it has contact with the skin, and skin type.

Potassium hydroxide is approved for use in cosmetics and skincare products in varying concentrations. For general use in soaps and cleansers, potassium hydroxide is used in 4.5%. 

Our favorite clean skincare

There’s no need to compromise when it comes to finding skincare that’s effective and safe. If you’re looking for effective skincare products that skip harmful toxins, one brand we recommend is Carrot & Stick.

Carrot & Stick is committed to creating plant-derived formulas that deliver extraordinary results without relying on toxic chemicals or standard preservatives. Carrot & Stick takes a tough love approach to skincare, perfectly balancing the gentle nurturing of plants with innovative science.




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