A minimalist hypochlorous acid serum with genuine dermatology-organization validation and a near-perfect irritation profile. It won't replace your actives, but for reactive skin mid-flare, it's one of the few 'serums' that does exactly what it promises without the stinging that usually accompanies soothing claims. The $34 price for five ingredients is the only real friction point.
SOS Intensive Rescue Serum
A minimalist hypochlorous acid serum with genuine dermatology-organization validation and a near-perfect irritation profile. It won't replace your actives, but for reactive skin mid-flare, it's one of the few 'serums' that does exactly what it promises without the stinging that usually accompanies soothing claims. The $34 price for five ingredients is the only real friction point.
Score Breakdown
A minimalist, exceptionally well-tolerated calming serum with genuine triple-organization dermatology validation. Price is the only meaningful deduction — you're paying serum money for what is essentially stabilized saltwater.
Data Confidence: high
This serum has been on market since 2022 with thousands of Sephora reviews, three separate dermatology organization seals of acceptance, and extensive write-ups from reactive-skin communities.
0/100
Overall Score
Ingredient Quality 0
Value for Money 0
Suitability Breadth 0
Irritation Risk (↑ = safer) 0
Assessment
Pros
- Near-zero irritation profile on compromised, broken, or flaring skin
- Triple-validated by the National Eczema, Psoriasis, and Rosacea organizations
- Stabilized HOCl remains active for months unlike unstabilized alternatives
- Fungal-acne safe, pregnancy-safe, and suitable for post-procedure recovery
- Layers invisibly under any serum, moisturizer, or sunscreen without pilling
- Calms flushing and inflammation within minutes of application
- No fragrance, no essential oils, no sensitizing preservatives
- Pump delivery allows targeted dosing on specific flare areas
Cons
- Price feels steep for a five-ingredient, mostly-water formulation
- Provides no hydration, barrier repair, or traditional serum benefits
- Faint chlorine scent on application may put some users off
- Must be used within six months of opening or potency declines
- Easy to underestimate the dose because the texture feels like nothing
Full Review
Here is a fun exercise: turn the bottle around, read the ingredient list, and count. Water. A mineral stabilizer. A pH buffer. Salt. Hypochlorous acid. Five ingredients. No niacinamide, no ceramides, no centella extract, no fancy peptides. If you're used to the twelve-syllable INCI lists of most modern serums, your first instinct is probably to suspect the bottle is a joke. It is not. It is the most deliberate five ingredients Tower 28 could have put in a bottle, and understanding why is the entire point of this product.
Hypochlorous acid is the same compound your own immune cells generate during wound healing. Hospitals have used it for decades in wound care, burn units, and ophthalmic irrigation because it is genuinely antimicrobial and genuinely non-cytotoxic — a combination that is almost impossible to find in any other antibacterial agent. The catch is that pure hypochlorous acid in water is wildly unstable. Give it a few weeks in a non-stabilized format and you are left holding a bottle of very expensive tap water. For years this meant HOCl was either a freshly-mixed medical product or a gimmick-y salon sanitizer, neither of which belonged in a skincare routine. What Tower 28 did — and what the sodium magnesium fluorosilicate in this bottle is doing — is hold the HOCl stable enough that you can keep it on your nightstand and trust that it still works six months from now.
The texture experience is almost anticlimactic. You dispense a pump onto your palm and it looks and feels exactly like water because that is essentially what it is. There is no slip, no residue, no cushion, nothing to rub in. The first time I used it I genuinely checked the bottle to confirm I hadn't grabbed something by mistake. A few seconds after application there is a very faint chlorine note — not perfume-strong, not unpleasant, just the scent of the chemistry itself — and then it disappears. No tingle, no warmth, no stinging, even on the kind of cracked, weeping eczema patches where the gentlest 'soothing' serums usually cause you to inhale sharply.
Where the serum shows its hand is in what does not happen over the next few minutes. Flushed, reactive skin calms visibly within about a quarter of an hour. Inflammatory acne papules that were throbbing stop throbbing. Post-procedure redness after a peel or laser settles down faster than it would with plain moisturizer. None of this is dramatic in the Instagram-transformation sense. What it is is reliable. If you have rosacea, eczema, or perioral dermatitis, you already know that 'reliable' and 'soothing serum' do not usually belong in the same sentence.
The irritation profile is essentially zero, which is why this has become a fixture in dermatologists' own toolkits for patients coming off a prescription topical or in the middle of an active flare. It also happens to be fungal-acne safe, which is worth mentioning in a category where roughly half of everything labeled 'calming' contains a Malassezia-feeding oil or ester. Pregnancy-safe, breastfeeding-safe, newborn-safe for diaper rash — the same core formula the brand sells for facial use has been used by parents on their infants without issue, which tells you something about the tolerability ceiling.
The honest limitations are all structural rather than performance-based. You are not getting hydration from this, because water with a trace of salt does not hydrate skin any more than tap water does. You are not getting barrier repair the way a ceramide or panthenol formula would. You are not getting visible plumping or glow. This serum is a calming and antimicrobial step, full stop, and it needs to be layered with a real hydrator and a real moisturizer to close the routine properly. Treating it as a standalone serum is the fastest way to feel disappointed.
Value is the part where opinions split. Thirty-four dollars for what is mostly water will read as absurd to anyone who priced out the raw materials, and they are not wrong on the math. But raw materials pricing ignores the engineering problem of keeping HOCl stable for a year in an opaque glass bottle, and it ignores the validation work the brand did with three separate dermatology nonprofits to earn the seals on the box. Those seals are not decorative — each requires ingredient review and patient testing on the condition in question. For the person with chronic rosacea who has tried eight other 'soothing' serums and flared on six of them, the price is a rounding error. For the person with generally healthy skin who wants a nice serum, this is not the bottle to buy, and the brand would probably agree.
The bottom line: if your skin reacts to things, if you are coming off a course of tretinoin or accutane, if you have a flare-prone inflammatory condition, or if you just want the one product in your cabinet that you know will never sting, this is an exceptionally good purchase. If you are hunting for hydration, brightening, or anti-aging, keep looking — this serum is not built for that job, and it has the courage of its convictions about it.
Formula
Ingredients
The hero actives that drive this product's performance.
| Ingredient | Function | Evidence |
|---|---|---|
| Hypochlorous Acid | The entire active payload of this serum. A gentle antimicrobial naturally produced by white blood cells during wound healing, here stabilized in a water-based format to calm irritated skin, reduce surface bacteria on inflamed areas, and quiet the inflammatory cascade that drives flares of eczema, rosacea, and inflammatory acne. | well-established |
| Sodium Magnesium Fluorosilicate | A mineral clay derivative that stabilizes the hypochlorous acid so it remains active in the bottle rather than degrading into plain saltwater. Without it, HOCl products have a short shelf life — its presence here is what makes this serum viable as a leave-on treatment rather than a single-use rinse. | well-established |
| Sodium Phosphate | A pH buffer holding the formula near skin-neutral so the hypochlorous acid remains in its bioactive form rather than dissociating. Also helps prevent the stinging that off-pH antimicrobial sprays can cause on compromised skin. | well-established |
Full INCI List · pH 5.5
Water (Aqua), Sodium Magnesium Fluorosilicate, Sodium Phosphate, Sodium Chloride, Hypochlorous Acid
Product Flags
✓ Fragrance Free✓ Alcohol Free✓ Oil Free✓ Silicone Free✓ Paraben Free✓ Sulfate Free✓ Cruelty Free✓ Vegan✓ Fungal Acne Safe
Compatibility
Skin Match
Best For
sensitive oily combination dry normal
Works For
Not Ideal For
Addresses These Conditions
rosacea eczema acne sensitivity compromised skin barrier post procedure psoriasis
Routine Step
treatment
Time of Day
AM & PM
Pregnancy Safe
Yes ✓
Layering Tips
Apply to clean, dry skin before any water-based hydrators. Let it absorb for 30 seconds before following with your usual serum and moisturizer. Can be layered over active breakouts or flares as a targeted spot treatment.
Results Timeline
Immediate calming on stinging or flushed skin within minutes of application. Visible redness reduction in 3–7 days with twice-daily use on active flares. Full benefits — fewer flare frequency and shorter recovery windows — typically show up across 4–8 weeks of consistent use.
Pairs Well With
ceramidesniacinamidecentella-asiaticapanthenol
Sample AM Routine
- Gentle cleanser
- Tower 28 SOS Intensive Rescue Serum
- Ceramide moisturizer
- Mineral SPF
Sample PM Routine
- Gentle cleanser
- Tower 28 SOS Intensive Rescue Serum
- Barrier cream
Evidence
Science
The Science
The active in this serum is hypochlorous acid, a weak acid with the formula HOCl that is generated endogenously by neutrophils during the respiratory burst of innate immune response. Its dual status — potent broad-spectrum antimicrobial and simultaneously non-cytotoxic to human cells at physiological concentrations — has made it a workhorse in wound care and ophthalmic irrigation for decades. A 2014 review in the Journal of Drugs in Dermatology examined stabilized HOCl for skin applications and described a favorable profile for inflammatory dermatoses, including atopic dermatitis. Separate research on hypochlorous acid preparations has documented reduced S. aureus colonization on atopic skin, which is mechanistically relevant because S. aureus overgrowth is implicated in eczema flare severity. The stabilization chemistry matters as much as the active itself: unstabilized HOCl in water reverts to sodium chloride within weeks, which is why the sodium magnesium fluorosilicate and sodium phosphate buffer in this formula are functionally critical — they hold the equilibrium on the HOCl side of the reaction long enough to remain bioactive across the product's shelf life. The near-neutral pH also matters, because HOCl is most biologically active in its protonated form between pH 4 and 6, which this serum targets. What the seals from the National Eczema Association, National Psoriasis Foundation, and National Rosacea Society add is patient-level tolerability evidence — each organization requires ingredient review and real-world testing on the relevant patient population before awarding their seal.
References
- Stabilized Hypochlorous Acid Cleanser and Gel in Skin Disorders — Journal of Drugs in Dermatology (2018)
Dermatologist Perspective
Dermatologists frequently reach for hypochlorous acid as a low-risk first step for patients with reactive or actively flaring skin, particularly those with rosacea, atopic dermatitis, or post-procedure inflammation. Board-certified dermatologists note that stabilized HOCl preparations have become a quiet staple in clinical practice because they offer genuine antimicrobial action without the barrier disruption associated with benzoyl peroxide, alcohol toners, or acid-based cleansers. Many dermatologists recommend this product specifically because the stabilization chemistry actually works — a meaningful distinction in a category flooded with hypochlorous acid sprays that degrade before they leave the store shelf. It is commonly suggested as a layering step between cleansing and a prescription topical to reduce inflammation and as an adjunct during isotretinoin courses when patient skin is too compromised to tolerate most over-the-counter serums.
Guidance
Usage Guide
How to Use
Use on clean, dry skin as the first step after cleansing, morning and night. Dispense 2–3 pumps into your palm or directly onto the affected area, press gently into the skin, and wait about 30 seconds for it to absorb before layering any hydrating serum, moisturizer, or SPF on top. For targeted flare management, apply an extra pump directly to the reactive patch up to 3–4 times per day. It can safely be used before or after a prescription topical like metronidazole, azelaic acid, or tretinoin — many users find layering this first helps buffer the irritation those actives can cause. Finish opened bottles within six months to ensure the HOCl is still active.
Value Assessment
At $34 for 2 oz, this is priced as a boutique skincare serum despite having a simpler formula than most drugstore saline sprays. The honest assessment: you are paying for the stabilization technology, the dermatology validation seals, and the clinical track record of a brand that was founded specifically to serve reactive-skin patients. For someone with chronic rosacea, eczema, or post-procedure skin who needs something that reliably does not sting, the math works out because it replaces more expensive failed purchases. For someone with resilient skin who simply wants an extra calming step, a generic hypochlorous acid spray from a medical supply retailer will do the same basic thing at a fraction of the cost. No larger size is offered, so there is no per-ounce discount to factor in.
Who Should Buy
Anyone with rosacea, eczema, psoriasis, perioral dermatitis, inflammatory acne, or chronically reactive skin who has struggled to find a soothing product that doesn't sting. Also excellent for post-procedure recovery (peels, lasers, microneedling) and as a gentle buffer on nights you use tretinoin or other prescription retinoids.
Who Should Skip
Anyone looking for visible hydration, brightening, or anti-aging benefits from a serum — this formula provides none of those things. Skip if your skin is generally tolerant and you want your serum budget to do more functional work, or if the $34 price for a five-ingredient formula bothers you on principle.
Ready to try Tower 28 SOS Intensive Rescue Serum?
Details
Details
Texture
Pure water-thin liquid with zero slip, cushion, or residue. Feels exactly like applying a fine mist of saline.
Scent
Very faint pool-chlorine note on application that dissipates within seconds — a byproduct of the hypochlorous acid chemistry, not an added fragrance.
Packaging
2 oz frosted glass bottle with a pump dispenser. Opaque packaging matters here — hypochlorous acid degrades in light, so the glass helps preserve potency.
Finish
invisiblelightweightfast-absorbing
What to Expect on First Use
On first use you may notice the faint chlorine smell and wonder if anything is happening — there's no slip, no active tingle, no visible layer. Within minutes, flushed or stinging skin usually feels noticeably calmer. No purging, no adjustment period.
How Long It Lasts
Approximately 2–3 months with twice-daily full-face application, or 4–5 months if used as a targeted spot treatment on flares only.
Period After Opening
6 months
Best Season
All Year
Certifications
National Eczema Association SealNational Psoriasis Foundation SealNational Rosacea Society SealCruelty-FreeVegan
Background
The Why
Founder Amy Liu built Tower 28 around products her daughter — who has severe eczema — could actually use. The SOS line grew out of the observation that hypochlorous acid, long used in hospital wound care, was nearly impossible to find in a stable, consumer-friendly format. The Intensive Rescue Serum was positioned as the more targeted sibling to the Daily Rescue Spray for flare-ups requiring a precise dose.
About Tower 28 Emerging Brand (2–5 years)
Tower 28 was founded in 2019 by Amy Liu, a beauty industry veteran whose daughter has severe eczema. The brand has earned seals from the National Eczema Association, National Psoriasis Foundation, and National Rosacea Society — rare multi-organization validation for a young indie brand.
Brand founded: 2019 · Product launched: 2022
Myth vs. Reality
Myths
Myth
Hypochlorous acid is the same as bleach and will damage skin.
Reality
At the low concentrations and near-neutral pH used here, HOCl is the same compound your own immune cells produce during wound healing. It is fundamentally different from sodium hypochlorite (bleach) and has a strong safety record in wound care and ophthalmology.
Myth
A five-ingredient serum can't really do anything.
Reality
Simplicity is the point — reactive skin reacts to actives, preservatives, and extracts. Stripping the formula to water, salt, buffer, and active is what makes it tolerable on broken or inflamed skin where most 'soothing' serums still cause stinging.
FAQ
FAQ
What's the difference between the SOS Intensive Rescue Serum and the Daily Rescue Facial Spray?
Both rely on stabilized hypochlorous acid as the active, but the serum comes in a pump bottle for controlled, targeted dosing on active flares, while the spray is a full-face mister for daily calming. The serum is better suited to focused treatment of rosacea or eczema patches; the spray is more convenient for whole-face use or throughout the day over makeup.
Can I use this with tretinoin or other retinoids?
Yes — the pH-neutral, active-free base makes it an ideal buffer on nights you use tretinoin. Many users apply this first to calm the skin, wait 30 seconds, then layer their retinoid and moisturizer on top.
Is it safe to use during a rosacea or eczema flare?
This serum holds the National Rosacea Society, National Eczema Association, and National Psoriasis Foundation seals specifically because it was tested on compromised skin. The minimal ingredient list and near-neutral pH mean it generally doesn't sting even on broken or weeping skin.
Will it treat active acne?
It won't unclog pores or turn over skin cells the way salicylic acid or a retinoid does, but the mild antimicrobial action of hypochlorous acid can reduce surface bacteria on inflamed papules and calm the redness around them. Think of it as a supportive player alongside a BHA or benzoyl peroxide routine, not a replacement.
Why does it smell faintly like a swimming pool?
That's the hypochlorous acid itself — the same compound your immune system produces during wound healing also happens to share a molecular family with pool disinfectants. The scent dissipates within seconds and is not an added fragrance.
How long does a bottle last?
Used twice daily across the full face, most people finish the 2 oz bottle in about 2–3 months. Tower 28 recommends using it within 6 months of opening because hypochlorous acid slowly loses potency once exposed to air and light.
Is it safe during pregnancy and while breastfeeding?
Yes — hypochlorous acid, saline, and mineral buffers have no known issues in pregnancy or lactation, and there are no retinoids, salicylic acid, or essential oils in the formula to raise concerns.
Community
Community
Common Praise
"Calms redness almost immediately"
"No stinging on broken or irritated skin"
"Helps shorten eczema and rosacea flare duration"
"Works for fungal acne-prone skin"
Common Complaints
"Expensive for a five-ingredient formula"
"Feels like water — some expect more from a serum"
"Short shelf life once opened"
Notable Endorsements
National Eczema Association Seal of AcceptanceNational Psoriasis Foundation Seal of RecognitionNational Rosacea Society Seal of Acceptance
Appears In
best serum for rosacea best serum for eczema best hypochlorous acid serum best serum for sensitivity best serum for compromised skin barrier
Related Conditions
rosacea eczema acne sensitivity compromised skin barrier
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