You’ve probably spotted it on an ingredient label and thought, “Wait… sodium hydroxide? Isn’t that a chemical used in drain cleaner?” You’re not wrong. Sodium hydroxide is indeed a powerful compound — but when used correctly in skincare, it serves a very different and surprisingly important role. So let’s break it down. Is sodium hydroxide in skin care safe? What does it actually do? And should you be worried?
Let’s take a close look at the facts.
What Is Sodium Hydroxide?
Sodium hydroxide, also known as lye or caustic soda, is a strong alkaline compound. On its own, it’s extremely corrosive and can be dangerous. But in skincare, it’s used in very small, carefully controlled amounts.
Its main role in beauty products? Balancing pH levels. That’s right — sodium hydroxide is often added to adjust the acidity of a product, making it safe and effective for your skin.
Why Is Sodium Hydroxide in My Skincare?
You’ll usually find sodium hydroxide in products like:
- Cleansers
- Soaps
- Creams and lotions
- Hair relaxers
It’s not there to clean or treat your skin directly. Instead, it helps create a stable product with a skin-friendly pH. Think of it as the ingredient that ensures everything else in the bottle works properly.
In bar soaps, sodium hydroxide is also used in a process called saponification — the chemical reaction that turns oils and fats into soap. Once this reaction is complete, no sodium hydroxide is left in the final product.
Is Sodium Hydroxide Safe for Skin?
The short answer? Yes — when used in tiny amounts, it is considered safe by dermatologists and regulatory bodies.
According to the Cosmetic Ingredient Review (CIR) panel, sodium hydroxide is safe in concentrations of up to 5 percent in rinse-off products and 2 percent in leave-on products. Most skincare items contain much less than that.
But there are a few things to keep in mind:
- Sensitive skin: People with very sensitive skin may experience irritation if the product contains too much sodium hydroxide
- Overuse: Using too many alkaline products can disrupt your skin’s acid mantle, which protects against bacteria and moisture loss
- pH matters: Sodium hydroxide is often used to bring a product to a balanced pH, which is critical for skin health
Benefits of Sodium Hydroxide in Skin Care
While it doesn’t provide direct skincare benefits like hydration or exfoliation, sodium hydroxide does play a crucial support role.
Here’s why it’s helpful:
- Keeps product pH in check
- Ensures formulas remain shelf-stable
- Helps active ingredients work as intended
- Plays a key role in soap making (saponification)
Without sodium hydroxide, your favorite moisturizer or cleanser might not be nearly as effective or safe to use.
Should You Avoid It?
Unless you have extremely sensitive or compromised skin, there’s usually no need to avoid products with sodium hydroxide — especially if it’s listed near the bottom of the ingredient list, which means it’s in low concentration.
Here’s when you might want to be cautious:
- If your skin is already irritated or reactive
- If you’re using strong acids or retinoids, which can make skin more sensitive
- If you’re noticing dryness or tightness after use
In those cases, it’s best to patch test new products or speak with a dermatologist.
Common Myths About Sodium Hydroxide
Myth 1: It’s toxic. Truth: Sodium hydroxide is dangerous in raw form, but in tiny amounts in skincare, it’s neutralized and regulated.
Myth 2: It’s only used in industrial products. Truth: Yes, it’s used in industrial cleaners, but it’s also an essential part of making safe soap and balancing pH in skincare.
Myth 3: It’s harmful for all skin types. Truth: Most people tolerate it just fine, especially in well-formulated products.
FAQs About Sodium Hydroxide in Skincare
Does sodium hydroxide cause acne?
No, sodium hydroxide isn’t known to cause breakouts. If anything, it helps stabilize the product so it doesn’t irritate your skin.
Can sodium hydroxide burn skin?
Only in high concentrations. The small amounts used in skincare are well below dangerous levels.
Why is sodium hydroxide in soap?
It’s part of the chemical reaction that turns fats and oils into soap. Once saponified, it’s no longer present in the final product.
Is it safe during pregnancy?
Yes. Sodium hydroxide in cosmetics is not considered a risk during pregnancy when used as directed.
Final Thoughts
Sodium hydroxide might sound scary at first, but in skincare it’s not the villain it’s made out to be. Used properly, it’s a safe and functional ingredient that helps products do their job.
So the next time you see sodium hydroxide on a label, don’t panic. Instead, focus on the overall formulation and how your skin reacts. That’s the real test of whether a product deserves a place in your routine.