Introduction
Hypochlorous acid (HOCl) is not yet another laboratory-formulated compound that promises unbelievable outcomes and sustainable results when it comes to dermatological use. HOCl is, in fact, a molecule found naturally in your body and is produced by the cells of your body’s immune system.
HOCl has been used as an antiseptic and bactericidal agent since the First and Second World Wars, with applications extending to wound care, post-surgery care, scar management, dentistry, ophthalmology, and, more recently, the dermatological treatment of various skin conditions. Based on scientific evidence and clinical trials of its biochemical and pharmacokinetic properties, it is suggested for use as an adjunct aesthetic skincare tool to enhance skin protection, healing, renewal, and calming.
Key Takeaways
- Biomolecular Defense System
HOCl is an endogenous molecule produced by your body’s white blood cells as part of your immune system’s initial defense mechanism, fighting potential infection and assisting in the wound healing process.
- Selective Oxidant
Its functions include breaking down microbes while sparing the normal bacteria present on your skin’s microenvironment, while simultaneously protecting your skin barrier.
- Calming Properties
In addition to its antimicrobial actions, HOCl reduces inflammation, redness, and irritation associated with certain skin conditions.
- Repairing Agent Without Causing Disruption
Wound healing, collagen production, and skin cell renewal are also part of its mechanisms of action.
- Quality of HOCl Products is Key
It is essential that the products you use are approved and have undergone the necessary quality control to ensure they do not degrade rapidly or contain high concentrations that can cause irritation rather than provide protection. Determine that HOCl formulations are stable at the appropriate concentrations and pH-regulated to enhance antibacterial, anti-inflammatory, and wound-healing effects.
How Does HOCl Work: Its Mode of Action
The mechanism of action involves moving through bacterial cell walls and breaking down bacterial enzymes, proteins, and DNA, ultimately disrupting bacterial function. Bacterial organisms, such as Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Streptococcus pyogenes, which can cause infections, are targeted by HOCl; in turn, it spares your normal (or commensal) bacteria on your skin.
Alongside its antimicrobial action, it also has soothing properties for irritation, reduces redness, and provides hydration. With the hydration step, HOCl neutralises free radicals (oxidative stress molecules that damage your skin cells when not removed by your body’s antioxidant defense system) and targets cytokines (such as IL-6, involved in the inflammatory process, and IL-19, associated with psoriasis).
A brief overview of the cellular and molecular properties is provided in the long-term benefits section, offering a closer look at how these mechanisms operate.
How is HOCl Derived from an Endogenous Source to be Safe for Skincare?
HOCl is formulated to mimic your body’s normal physiological process, created by white blood cells during a natural immune response as part of your body’s initial defense against potential infection. White blood cells generate HOCl using an enzyme called myeloperoxidase. This enzyme then combines with chloride ions (from salt) and hydrogen peroxide, along with an oxidant, during an “oxidative burst,” when your body targets and fights foreign particles, such as bacteria. Despite endogenous (naturally occurring in your body) HOCl being efficient at a pH 5.0–6.5, it has a short lifespan.
Skincare product manufacturers have replicated this process through a method called electrolysis. They use a single-cell or single-membrane system to purify salt (NaCl) from reverse osmosis water (the reverse osmosis process removes most contaminants, including salt, chlorine, and other unwanted particles, from water). By adding a low-voltage current to the water, NaCl is broken up. The unbound chloride ions (Cl–) move to the positive electrode (anode) connected to the electrical source, where they oxidise and form HOCl – this HOCl is more than 95% free of chlorine. The unbound sodium ions (Na+) maintain the solution’s pH by not forming harsh byproducts, such as NaOH. Specific concentrations (for example, 50-500 ppm) are controlled to ensure skincare products are gentle for use.
It is essential to select the correct HOCl product, preferably one buffered at pH 4.5-6.5, since raw HOCl can be easily degraded by light, heat, oxygen, or pH changes. Furthermore, it is flushed with nitrogen to prevent exposure to air and bottled in opaque packaging to ensure a shelf life of 12-24 months, reducing the need for preservatives or refrigeration.
Long-term Benefits on a Cellular and Molecular Level
When used consistently for weeks to months, it targets different cellular areas involved in, for instance, wound-healing processes associated with conditions such as eczema.
- Fibroblast activity is enhanced by increasing their movement (fibroblasts are the cells responsible for maintaining the extracellular matrix in the skin, providing strength, elasticity, and structural integrity).
- Increase of epithelial cells and angiogenesis (stimulating the formation of new blood vessels), especially during the wound-healing process.
- Reduces the enzyme matrix metalloproteinases (MMPs) that are responsible for breaking down collagen, while HOCl also promotes collagen production.
- Also aids in skin barrier repair and promotes barrier strengthening, thereby maintaining its integrity.
- Regulates chronic inflammatory states by inhibiting IKK (I-kappa B kinase), which normally regulates NF-kappa B activity. NF-kappa B is typically involved in inflammatory processes that, in turn, contribute to aging.
- Adds to the balance of your skin’s microbiome (its normal flora).
- Builds more resilient and smoother skin.
The last two beneficial factors have been associated with the management of rosacea, psoriasis, and dermatitis. Studies have suggested that HOCl use reduces harmful bacterial load and contributes to healing without the development of resistance to prolonged HOCl use.
A Deeper View into the Cellular and Molecular Effects of HOCl Use
The sites of interest that HOCl targets are the stratum corneum and epidermis – it functions as a selective oxidant. Selective, because it only targets harmful bacteria without disrupting the healthy dermis layers of the skin, and an oxidant, because it reacts through a biochemical reaction, called oxidation, with sulfur-rich residues (cysteine and methionine) present in bacterial proteins and biofilms. This selective oxidative action leads to a quick microbial cell death.
Moreover, from a molecular perspective, HOCl induces a reversible redox enhancement with chloramines, such as taurine chloramine, thereby reducing the activity of inflammatory-promoting pathways (for instance, NF-kappa B and molecular mediators, such as iNOS and COX-2), as well as free radicals. At the same time, it spares the body’s antioxidants. Through this mode of action, it mimics your innate immune system, thereby promoting skin renewal and reducing oxidative stress from UV rays and pollution. Following UV exposure, AP-1 signalling is activated and, in turn, promotes the activity of tumor suppressor genes (for instance, Txnip); however, prospective research is required to further elucidate these mechanisms.
But Who is HOCl Intended For?
Individuals who can benefit from HOCl use include:
- Patients with acute or chronic wounds, especially following postoperative care.
- Provides healing and reparative functions after certain dermal aesthetic procedures, such as microneedling, laser resurfacing, and injections.
- Those who have atopic dermatitis and experience itching due to the skin condition (decreasing aureus).
- Seborrheic dermatitis
- Acne vulgaris
- Rosacea
- Psoriasis flares
- Diabetic ulcers
- Hypertrophic or keloid scars
- Also aids those with sensitive skin
- It can be used by individuals who tend to experience microbial overgrowth and who are looking for a gentle antimicrobial support product.
- It is also considered safe for children and the elderly due to its endogenous safety profile.
Recently, studies have found that it also supports the treatment of wound infections, blepharitis, and viral skin infections, such as herpes.
HOCl Use: Is It Safe and What Are the Possible Side Effects?
Generally, HOCl is considered safe for long-term use, provided the product is correctly formulated and stabilised by pH buffering. Clinical studies have indicated that these products are well tolerated, with no serious adverse events reported.
Based on dermatological reviews, HOCl has a high safety margin as an endogenous substance, with no cytotoxicity reported at therapeutic concentrations. It is also reported to be highly tolerable compared with products such as povidone-iodine or chlorhexidine, especially for wound care. Moreover, traditional alcohol-based cleansers and benzoyl peroxide are known to be harsh on the skin barrier; however, HOCl does not affect the skin barrier to the same extent as these conventional antimicrobials.
One study reviewing 61 clinical trials using HOCl for various chronic applications, from ulcers, dermatitis, and scars, has indicated the tolerability and no evidence of resistance or systemic toxicity. From a regulatory standpoint, it is also considered safe for use because it does not cause irritation of the skin, mucosa, or eyes.
Potential side effects to consider:
- Mild dryness of skin.
- Sensitivity or stinging when the skin is broken.
- Redness can occur, although it is rare (<5% in studies), and is also associated with overuse or with unstable formulations that break down to hypochlorite.
- When HOCl is used at high concentrations or for prolonged periods without breaks, the normal microenvironment can be disrupted, leading to contact dermatitis.
Real-World Applications and Insights
- It is advised to start with a low concentration over a shorter period; adopt the “low and slow” principle when you start using HOCl.
- The contact time for HOCl use is important – allowing it to air-dry on the skin is recommended, as it is the most effective.
- Keep an eye on skin barrier disruption.
- And pair HOCl with moisturisers.
- Do not combine it with strong exfoliants, retinoids, or high-concentration vitamin C products, as this can reduce its effectiveness.
- As it is known to function as an antimicrobial, prolonged or unnecessary use should be monitored to avoid disruption of the normal microbial microenvironment.
- It is essential to discuss the long-term use of any product with a dermatologist or dermal aesthetician for a holistic take on treating a chronic skin condition.
- Note that HOCl does not function as a cleanser; therefore, relying on it to remove oils, makeup, or environmental debris is not recommended. It is an antimicrobial and soothing adjunct.
Conclusion
The availability of HOCl as an antimicrobial, anti-inflammatory, and reparative skincare product highlights the integration of the human biological system, clinical science, and applications to modern skincare routines.
Instead of using conventional methods that can disrupt the skin’s structure, integrity, strength, and quality, HOCl offers a way to enhance, soothe, and protect the skin via a mechanism already present in the body. With these properties that cultivate a balanced approach to skincare, without disrupting the skin barrier or the normal microbiome, it further emphasises its use as an adjunct skincare product as well as for dermal aesthetics and beyond.
And when you take the time to ensure you know what your HOCl product contains and use it thoughtfully, as recommended by your dermal aesthetician or dermatologist, it can provide sustainable outcomes as an adjunct.
Forget quick-fix, trend-driven applications; long-term skin health, strength, and recovery are priorities.