What HOCl is and why it works on skin
Hypochlorous acid (HOCl) is a weak acid that the body produces physiologically in neutrophil granulocytes as part of innate immunity. The enzyme myeloperoxidase catalyses the reaction of hydrogen peroxide with chloride ions to form HOCl — the molecule responsible for most of a white blood cell's antimicrobial action inside the phagocytic vacuole. Stabilised in a bottle, it works the same way, just applied from the outside.
For dermatology, three mechanisms matter at once:
- Oxidative destabilisation of pathogens — HOCl reacts with thiol groups, methionine and other amino acids in the membrane proteins of bacteria and fungi. The mechanism is so general that resistance to it is practically impossible to develop.
- Mast cell modulation — reduces the release of histamine, IL-6 and TNF-α, which topically calms itching and erythema without a corticosteroid mechanism.
- Selectivity — unlike peroxide, alcohol or benzoyl peroxide, HOCl does not damage fibroblasts, keratinocytes or growth factors. It lowers the pathogenic load but does not stall healing or wreck the skin barrier.
All the dermatological indications described below follow from these three properties.
Acne — daily routine and acute inflammation
Why acne and HOCl go together
Acne is not "dirty skin". It is a multifactorial inflammation of the sebaceous gland, combining seborrhoea, follicular hyperkeratosis, Cutibacterium acnes colonisation and a local inflammatory response. Classic topical therapy (benzoyl peroxide, salicylic acid, retinoids, antibiotics) targets one mechanism at the cost of dryness, desquamation and a disrupted skin barrier — which in many people leads to "compensatory seborrhoea" and a vicious circle.
HOCl works differently: it selectively reduces the C. acnes population in the follicles, dampens local inflammation and does not disrupt the hydrolipid barrier. It is not a monotherapy for moderate to severe acne — but it is an ideal foundation for a daily routine, a complement to retinoids and a gentle anti-inflammatory tool during acute flare-ups.
How to use it
- Morning routine: after gentle cleansing, 2–3 sprays on the face, let dry for 30 seconds, then serum / moisturiser / SPF.
- Evening routine: the same after removing make-up and cleansing. If you use a retinoid (tretinoin, adapalene), apply HOCl first — it helps calm retinoid-induced inflammation.
- Acute pimple or inflammatory lesion: 4–5× daily on the spot; markedly shortens how long the lesion lasts (the inflammatory component).
- Acne on the back, chest, shoulders: a spray is easy to apply over large areas — a solution where regular creams struggle to cover and where sweat and mechanical irritation build up.
Note: Active severe cystic acne or scarring acne always belongs in a dermatologist's care — HOCl is an adjuvant, not a substitute for systemic therapy.
Atopic eczema, dermatitis, psoriasis
The cycle HOCl helps break
In atopic dermatitis, Staphylococcus aureus colonisation plays a key role. Staphylococcal superantigens amplify the inflammatory response, the damaged barrier reopens the way for the bacterium — and the cycle repeats. The standard answer is topical corticosteroids and calcineurin inhibitors, but long-term use has well-known limits (skin atrophy, telangiectasia, tachyphylaxis).
HOCl is the first line between the bath and the corticosteroid: it reduces S. aureus colonisation, calms acute inflammation and buys time — either replacing the corticosteroid entirely or at least reducing how often it is needed.
How to use it during a flare-up
- Twice daily spray the affected areas, let absorb for 30–60 seconds, then apply a moisturiser (emollient). HOCl under the cream, not on top.
- In children it is safe including on the face (avoid direct eye contact); suitable as an alternative or complement to corticosteroid ointment, especially between flares.
- For itching: immediate relief of pruritus lasting 30–90 minutes — especially useful at night.
- After showering spray first, then apply emollient — barrier repair without rubbing a towel into irritated skin.
Psoriasis
In psoriasis the primary problem is dysregulated T-cell immunity, not bacteria. HOCl is therefore not a causal therapy, but it has a role in one specific scenario: secondary bacterial colonisation of psoriatic plaques (especially intertriginous, gluteal and retroauricular), where it calms the inflammatory overlay and reduces pruritus.
Acute inflammatory irritation
Sunburn
After excessive UV exposure, the skin develops UV-induced inflammation: ROS, pro-inflammatory cytokines, prostaglandins, mast-cell degranulation. HOCl applied topically 4–5× daily markedly shortens the perceived duration of burning and erythema — through a combination of a mild oxidative effect on surface bacteria and mast cell modulation. A complement to, not a replacement for, systemic pain relief in extensive sunburn.
Insect bites
Bites from mosquitoes, blackflies, horseflies, fleas — the typical mechanism is an injection of saliva containing vasoactive and allergenic peptides, followed by a local histamine reaction. Applied after a bite, HOCl markedly reduces itching and speeds up the regression of the papule. For some people it works so well that it becomes the main summer product in their first-aid kit.
Contact and irritant dermatitis
Reactions after contact with plants, metal, cosmetics, rubber or chemicals — a combination of allergic and irritant components. In the acute phase HOCl calms itching and erythema, reduces the secondary bacterial load from repeated scratching and creates conditions for healing. Extensive or recurrent reactions call for diagnosis by an allergist.
Rosacea — proceed with caution
Rosacea is more nuanced: the barrier is compromised and the skin highly reactive, so even gentle products sometimes trigger flushing. HOCl is generally well tolerated, but I recommend a patch test first on a small area for 3 days.
Care after dermatological procedures
This is the area where HOCl dominates — modern aesthetic and procedural dermatology uses it routinely:
Microneedling, derma roller, microcannulas
Once microchannels have been created, the skin stays open for 12–24 hours and is maximally susceptible to microbial contamination. HOCl is the standard for immediate post-treatment care: it lowers the risk of follicular inflammation, shortens erythema and supports smoother remodelling.
Chemical peels
After a glycolic, salicylic or TCA peel, the skin barrier is disrupted and desquamation is under way. HOCl helps calm the inflammatory component and protect against secondary infection without interfering with the peeling process.
Laser treatment (IPL, Fraxel, CO₂)
After ablative or non-ablative laser treatment, the standard risks are post-inflammatory hyperpigmentation (PIH) and infection. HOCl 4× daily for 5–7 days after the procedure is widely accepted in the aesthetic community as part of basic post-procedure care. Some peer-reviewed studies suggest a link with reduced scarring (less inflammation → less fibrotic remodelling).
Tattoos and permanent make-up
A fresh tattoo is essentially a large, controlled wound. HOCl is gentler than alcohol-based disinfectants and less occlusive than petrolatum (Bepanthen). Especially suitable in the first 48 hours.
Paediatric dermatology
The safety profile of HOCl (comparable to saline) makes it a preferred choice for children's skin in many common situations:
- Childhood eczema — see Chapter 03; HOCl is suitable even for infants, where avoiding corticosteroids is a priority.
- Diaper dermatitis — spray after every change (rather than wiping with a cloth), let dry, then apply a protective zinc paste on top. Gentler than frequent rubbing.
- Hand-foot-mouth, varicella (chickenpox) — HOCl calms itching and lowers the risk of secondary bacterial infection in scratched lesions.
- Minor scrapes and cuts — a key advantage for children: it doesn't sting. No fear of application.
- Baby acne (neonatal cephalic pustulosis) — a physiological condition driven by maternal hormones. HOCl shortens its duration without the need for pharmacological intervention.
For infections that look bacterial (impetigo with typical honey-coloured crusts, periorbital cellulitis, spreading erysipelas), a paediatrician's assessment is essential, usually along with systemic antibiotics — HOCl is not a substitute.
How it compares with the alternatives
HOCl vs. benzoyl peroxide (acne)
Benzoyl peroxide is a potent comedolytic and bactericidal agent, but it dries the skin significantly, irritates, causes desquamation and in many people triggers compensatory seborrhoea. HOCl is gentler, can be combined with other products and used long term without compensatory effects. In severe acne benzoyl peroxide still has its place — for mild acne or as maintenance, HOCl makes more sense.
HOCl vs. topical corticosteroid (eczema, dermatitis)
A corticosteroid is a fast and powerful anti-inflammatory tool, but repeated use carries known risks (skin atrophy, telangiectasia, tachyphylaxis, perioral dermatitis when used on the face). HOCl is not a substitute for a moderately to highly potent corticosteroid in acute severe inflammation, but it is well suited to the periods between flares, maintenance and mild flare-ups — and so reduces the corticosteroid burden.
HOCl vs. hydrogen peroxide
Peroxide "fizzes" — that is not a sign it is working, but oxygen being released by the catalase reaction in tissue. It damages fibroblasts and stalls healing; modern wound care is moving away from it. HOCl has comparable or greater antimicrobial efficacy with minimal cytotoxicity.
HOCl vs. ethanol / sanitising gel
Ethanol works fast and suits intact skin (e.g. before an injection). Downsides: it stings in a wound, dries the skin and disrupts the barrier with repeated use. For daily facial care, children's skin and sensitive areas, HOCl is far better tolerated.
HOCl vs. topical antibiotic
Topical antibiotics (mupirocin, neomycin, clindamycin) carry a real risk of resistance, and neomycin causes contact allergy in up to 1 in 5 patients. HOCl has neither problem. A genuine skin infection calls for an antibiotic based on a specialist's assessment — HOCl has a preventive and adjuvant role, not a curative one.
Product quality and limitations
What makes a quality HOCl product
HOCl is a finicky molecule. The stability of the solution depends on pH, concentration, packaging material and UV exposure. Check before buying:
- pH 5–7 — below 5 there is a risk of irritation; above 7 HOCl breaks down into the less effective hypochlorite ion.
- Concentration 100–200 ppm — fully sufficient for topical dermatological use; higher ppm only increases the risk of irritation without improving efficacy.
- Expiry date — good stabilisation achieves 18–24 months. No date, or a "shelf life of 6 months", probably means stabilisation is lacking.
- A single active ingredient: HOCl (or "electrolysed water"). An added botanical extract, fragrance or preservative usually means the molecule is inactive — HOCl does not tolerate co-formulation.
- Opaque packaging — HOCl is sensitive to UV.
- Medical grade — for open wounds and post-procedural use, prefer a product with FDA 510(k) clearance or CE-MD marking for topical application.
What HOCl is not
- It is not a treatment for an existing bacterial infection. Spreading erythema, fever, pus, increasing pain — consult a specialist and get systemic treatment.
- It is not a causal therapy for psoriasis, autoimmune dermatoses or severe cystic acne. An adjuvant, not a substitute.
- It is not an intranasal or inhaled product. Topical cosmetic HOCl is formulated differently from products for mucous membranes.
- It is not absolutely allergen-free. Irritation is rare — typically with unstable products whose pH has drifted or that contain added preservatives.
Bonus: uses beyond dermatology
The same bottle also works well for: disinfecting minor scrapes and cuts, care after hair removal and shaving (folliculitis), reducing foot odour (the bacterial component), and — for users of injectable peptides — as a gentle alternative to an alcohol swab for both the injection site and the vial's rubber stopper.