Hypochlorous acid (HOCl) has been used in medicine and wound care for years, but it has recently attracted renewed interest for something much closer to home: the skin, eyes, and nasal passages.

The name can sound intimidating. But HOCl is actually a molecule your own body naturally produces as part of its first-line immune response.

So what exactly is hypochlorous acid—and what might it have to do with breathing through your nose?

What is hypochlorous acid?

Hypochlorous acid is a weak acid made from hydrogen, oxygen, and chlorine. Importantly, HOCl is also produced naturally by our white blood cells.

When the immune system encounters microbes or tissue injury, certain white blood cells generate HOCl as part of the body's innate immune response. It participates in the process by which immune cells help control microorganisms and respond to damaged tissue.

Modern manufacturing can reproduce HOCl in a controlled aqueous solution, typically using water, salt, and electrolysis.

The result is a very different material from household bleach.

HOCl should not be confused with sodium hypochlorite bleach. The chemistry, concentration, formulation, pH, and intended use matter. Formulated HOCl products designed for use on skin or other biological surfaces are produced under very different conditions than household cleaning products. Researchers have found that formulation and pH have a major influence on both HOCl's activity and tolerability.

Why is HOCl used in wound care?

Long before HOCl became popular in skincare, it was being investigated and used in medical settings.

One reason is its combination of antimicrobial activity and relatively favorable tissue tolerability when appropriately formulated.

Research has explored HOCl for:

• Wound cleansing

• Chronic wounds

• Surgical irrigation

• Skin conditions involving inflammation or microbial burden

• Ophthalmic and eyelid hygiene

• Dental applications

• Other medical and healthcare settings

A review of topical HOCl literature found evidence supporting antimicrobial and anti-inflammatory properties, while also emphasizing that the characteristics of the particular formulation—especially pH and stability—matter considerably.

In a clinical study involving patients with chronic open wounds, HOCl irrigation was compared with saline irrigation during wound debridement. The researchers evaluated bacterial counts and wound outcomes, contributing to the broader body of evidence investigating HOCl in wound management.

More recently, a 2026 systematic review and network meta-analysis evaluated HOCl as a surgical irrigation solution across multiple types of surgery. The analysis found a lower risk of surgical-site infection with HOCl irrigation compared with basic irrigation in the studies included, although the authors also noted that additional research is needed and that results can vary according to the surgical context.

This broader medical history is important because it helps explain why researchers are interested in HOCl beyond the skin.

What does this have to do with the nose?

The nose is not simply an empty passage for air.

The nasal cavity is lined with delicate mucosal tissue that helps warm, humidify, and filter the air we breathe. It is also home to a complex microbial environment and is constantly exposed to particles, allergens, microorganisms, dry air, and other environmental factors.

When the nasal passages become irritated or inflamed, people may experience congestion, excess mucus, crusting, post-nasal drainage, or a feeling that airflow is restricted.

This has led researchers to investigate whether appropriately formulated HOCl solutions could have a role in nasal hygiene and postoperative nasal care.

The evidence is still developing, but there are some interesting clinical findings.

HOCl after sinus surgery

One of the more directly relevant studies looked at patients who had undergone functional endoscopic sinus surgery (FESS) for chronic rhinosinusitis.

In the randomized study, 78 patients completed the trial. One group used a 0.02% HOCl nasal spray three times daily for two months, while the comparison group used normal saline nasal irrigation.

The researchers evaluated symptoms, nasal endoscopy, smell, nasal function, and bacterial cultures.

After two months, the HOCl group showed a significant improvement in endoscopic findings. Overall symptom scores also improved, although the improvement was not statistically significant within the HOCl group. The researchers concluded that HOCl nasal spray had a similar overall effect to saline irrigation in postoperative care and suggested that it could be a convenient alternative to saline irrigation in that setting.

That distinction matters.

The study does not establish that HOCl is a superior treatment for chronic sinusitis or that it will improve nasal breathing in everyone.

What it does show is that there is clinical research investigating appropriately formulated HOCl nasal spray as part of postoperative nasal care.

Could HOCl help support a cleaner nasal environment?

Potentially—but this is where it is important to be precise.

HOCl has antimicrobial activity, and laboratory and clinical research has demonstrated activity against a broad range of microorganisms. That makes it an interesting candidate for cleansing applications.

However, antimicrobial activity in a laboratory or wound-care setting does not automatically mean that spraying HOCl into the nose will eliminate bacteria, prevent infection, or treat sinus disease.

In fact, one study specifically examining HOCl and nasal secretions from patients with chronic rhinosinusitis found that the tested HOCl solution did not demonstrate an antibacterial effect on nasal secretions within five minutes.

That is a useful reminder: HOCl is promising, but nasal applications require evidence specific to the formulation, concentration, delivery method, and condition being treated.

For everyday nasal care, the more reasonable way to think about HOCl is as a potentially gentle cleansing solution that can be used to support nasal hygiene—not as a replacement for medical treatment.

What about inflammation?

Another reason HOCl is interesting is that its biological activity appears to extend beyond simply killing microorganisms.

Reviews of topical HOCl have described antimicrobial and anti-inflammatory properties, along with potential effects related to wound healing. These properties have helped drive research into HOCl for skin and wound applications.

For the nose, the potential relevance is straightforward:

A nasal passage that is exposed to dry air, allergens, environmental particles, mucus, or irritation is a biologically active surface. Keeping that surface clean and appropriately hydrated can be part of maintaining comfortable nasal function.

But it is important not to jump from that concept to a claim that HOCl "reduces nasal inflammation" or "opens the airways" in everyone. Those are clinical claims that require evidence for the specific product and use.

HOCl and nasal breathing

This is where HOCl becomes particularly interesting—but also where the distinction between nasal hygiene and mechanical nasal airflow matters.

Nasal breathing can be affected by many different factors, including:

• Nasal congestion

• Allergies

• Inflamed mucosa

• Excess mucus

• Structural narrowing

• Deviated septum

• Turbinate enlargement

• Nasal valve narrowing

• Dryness and crusting

• Postoperative changes

A cleansing spray cannot mechanically widen a narrowed nasal valve or correct a structural obstruction.

That is why we think about nasal health as having more than one component.

The nasal environment matters. And the physical airway matters too.

A well-formulated HOCl spray may support cleansing of the nasal passages, while a nasal dilator can address mechanical support of the nasal airway. These are fundamentally different mechanisms.

Why is HOCl being explored after nasal procedures?

Nasal and sinus surgery creates a particularly interesting environment for postoperative care.

After procedures such as FESS, the nasal cavity can undergo changes as tissue heals. Clinicians commonly use saline irrigation as part of postoperative care to help clear mucus, blood products, crusting, and debris.

Researchers have therefore explored whether HOCl could be used as an alternative or adjunct to conventional saline-based postoperative care.

The clinical study discussed above found that HOCl nasal spray produced postoperative endoscopic improvements comparable overall to saline irrigation, supporting continued investigation of HOCl in this setting.

A separate study of patients with persistent or recurrent chronic sinusitis following surgery also investigated HOCl plus saline irrigation compared with saline alone. The HOCl group demonstrated improvement in endoscopic scores, although the study did not show a significant difference between groups in symptom improvement.

Again, the takeaway is not that HOCl has been proven to treat postoperative sinus disease.

The takeaway is that there is enough clinical evidence to make HOCl an interesting subject of investigation in postoperative nasal care.

Is HOCl safe?

Safety depends on the product.

This is one of the most important points when talking about hypochlorous acid.

Not every chlorine-containing solution is HOCl, and not every HOCl formulation is intended for the same application.

Concentration, pH, purity, stability, packaging, and intended route of use all matter.

Research reviews have specifically emphasized that HOCl formulations can behave differently depending on their chemical characteristics. In particular, the balance between HOCl and hypochlorite changes with pH, which is one reason appropriately formulated products are important for biological applications.

For nasal use, consumers should therefore use only a product specifically formulated and labeled for nasal or mucosal application and follow its instructions.

A product intended for surface disinfection should never be assumed to be appropriate for the nose.

What HOCl can—and cannot—do

It is tempting to describe HOCl as a solution that "does everything."

The science is more nuanced.

What research supports

HOCl has been studied for:

• Antimicrobial activity

• Wound cleansing

• Surgical irrigation

• Skin and wound care

• Postoperative care

• Eyelid and ophthalmic hygiene

• Nasal applications

• Inflammatory skin conditions

There is meaningful research behind many of these applications, although the strength of evidence varies considerably by indication and formulation.

What still needs more research

For nasal health specifically, more research is needed to determine:

• Which concentrations are optimal for different nasal applications

• How frequently HOCl should be used

• Which delivery methods work best

• How it compares with saline for different conditions

• Whether it meaningfully changes nasal symptoms in specific patient populations

• Whether it has a meaningful effect on nasal microbial communities over longer periods

That is why we prefer to describe HOCl as a promising nasal-care technology rather than a cure-all.

A different way to think about nasal care

The nose is the body's first air filter.

It encounters everything we breathe before that air reaches the lower respiratory tract.

For some people, maintaining nasal hygiene is a simple part of daily wellness. For others, nasal care becomes particularly important during allergy seasons, periods of dryness, after certain procedures, or when the nasal passages are exposed to increased environmental irritation.

HOCl is interesting because it sits at the intersection of microbiology, wound care, and everyday hygiene.

It is a molecule the body already knows.

And decades of research into wound care and medical applications have given researchers a foundation for investigating what appropriately formulated HOCl might do on other biological surfaces—including the nose.

The science is promising.

But the most useful approach is also the most measured:

Use HOCl for what the evidence supports, choose a formulation designed for the intended application, and recognize that healthy nasal breathing depends on much more than one ingredient.

For people interested in improving nasal airflow, cleansing and caring for the nasal passages may be one piece of the picture. Understanding the physical structure of the airway is another.

And sometimes, better nasal breathing starts by looking at both.

References & Further Reading

1. Jiang R-S, Liang K-L. Effect of hypochlorous acid nasal spray as an adjuvant therapy after functional endoscopic sinus surgery. American Journal of Otolaryngology. 2022;43(1):103264.

2. Wu C-L, et al. Antibacterial Effect of Hypochlorous Acid Solution on Nasal Discharge from Patients with Chronic Rhinosinusitis. International Journal of Otolaryngology. 2018.

3. Del Rosso JQ, Bhatia N. Status Report on Topical Hypochlorous Acid: Clinical Relevance of Specific Formulations, Potential Modes of Action, and Study Outcomes. Journal of Clinical and Aesthetic Dermatology. 2018.

4. Hypochlorous Acid as a Potential Wound Care Agent: Part I. Wound Repair and Regeneration.

5. Hypochlorous Acid as a Potential Wound Care Agent: Part II. Wound Repair and Regeneration.

6. Ayers D, et al. The safety and effectiveness of hypochlorous acid used as surgical irrigation solution to reduce postoperative complications: A systematic review and network meta-analysis. American Journal of Infection Control. 2026.

A note on medical information: This article is for educational purposes and is not medical advice. HOCl products differ in formulation, concentration, intended use, and regulatory status. If you have had nasal or sinus surgery, have significant nasal symptoms, or have been diagnosed with a nasal or sinus condition, follow your healthcare professional's postoperative or treatment instructions.