What to Avoid Mixing with Hypochlorous Acid

The short answer is that you should avoid mixing hypochlorous acid (HOCl) directly with antioxidants like Vitamin C while the skin is still wet. Because hypochlorous acid is an oxidizing agent and Vitamin C is an anti-oxidant, applying them at the exact same time causes them to cancel each other out. This reaction doesn't harm your skin or cause a dangerous chemical burn, but it does render both products ineffective—essentially turning your expensive serums into expensive water.

The Chemistry of Cancellation

To understand why certain pairings don't work, we have to look at how hypochlorous acid functions. HOCl works through oxidation. It seeks out electrons to steal from pathogens (bacteria, viruses, fungi), which destroys their cell walls.

Antioxidants, such as L-Ascorbic Acid (Vitamin C), Vitamin E, or Resveratrol, work by donating electrons to unstable molecules (free radicals) to neutralize them.

If you spray hypochlorous acid and immediately slap on a Vitamin C serum, the HOCl attacks the Vitamin C. The HOCl uses up its oxidizing power on the Vitamin C instead of the bacteria, and the Vitamin C uses up its antioxidant power on the HOCl instead of protecting your skin.

The "Wait to Dry" Rule

The good news is that you don't have to banish these ingredients from your routine entirely. You just need patience.

Hypochlorous acid is highly unstable once it hits the air and skin. It does its job of killing bacteria within seconds and then rapidly breaks down into harmless saline (salt and water). Once the hypochlorous acid has dried completely on your face, it is no longer active.

This means you can safely use Vitamin C, Retinol, or other actives in the same routine, provided you wait for the HOCl to dry fully (usually 30 to 60 seconds).

What About Retinol and Chemical Exfoliants?

While Vitamin C is the biggest "clash," you should also be mindful of Retinoids and Exfoliating Acids (AHAs/BHAs).

1. Retinol: Retinol is a notoriously unstable molecule that degrades easily in the presence of light, air, and oxidizers. Applying it over damp, HOCl-covered skin could theoretically reduce the potency of the retinoid.
2. AHAs/BHAs: These acids require a specific low pH to work. While HOCl is pH balanced (around 5.5), flooding the skin with it right before or after a chemical peel might alter the pH environment slightly, potentially reducing the exfoliant's "bite."

The Protocol:

1. Cleanse skin.
2. Spray Hypochlorous Acid.
3. WAIT until skin is 100% dry to the touch.
4. Apply Vitamin C, Retinol, or Exfoliants.

Safe to Mix: Hyaluronic Acid & Moisturizers

Not everything needs a wait time. Ingredients that are not "actives" or prone to oxidation are perfectly safe to apply over damp skin. In fact, Hyaluronic Acid works better when applied over damp skin.

Because Hyaluronic Acid is a humectant (it holds water), applying it while your face is still slightly damp with hypochlorous acid helps lock that hydration in. Similarly, simple moisturizers, ceramides, and peptides generally do not react negatively with HOCl.

Frequently Asked Questions

Can I use hypochlorous acid after a clay mask?

Yes. Clay masks can sometimes leave the skin feeling stripped or vulnerable. Spraying HOCl afterward is a great way to soothe the skin and prevent bacteria from entering freshly unclogged pores.

If I wait for it to dry, won't my skin get dehydrated?

If you have very dry skin, waiting for a spray to fully evaporate might feel tight. In this case, spray the HOCl, wait 30 seconds for the antimicrobial action to work, and if it's not totally dry, you can pat it dry with a clean towel before applying your hydrating serums.

Does hypochlorous acid deactivate benzoyl peroxide?

Benzoyl peroxide is also an oxidizer.11 Using them together can be very drying and potentially irritating because you are doubling up on oxidative stress. It is best to use them at different times of day (e.g., HOCl in the morning, Benzoyl Peroxide at night).

Disclaimer: The content provided in this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

If you’re looking for a hypochlorous acid spray to support your skin barrier, you can learn more about our formulation here. It’s also available through select retailers, including Amazon.

References:

[1] Gold, M. H., et al. (2020). Hypochlorous Acid: A Review. Journal of Cosmetic Dermatology, 19(2), 270-277.

[2] Telang, P. S. (2013). Vitamin C in Dermatology. Indian Dermatology Online Journal, 4(2), 143–146.

[3] Draelos, Z. D. (2016). The Science of Cosmeceuticals. Journal of Cosmetic Dermatology, 15(1), 12-15.