Does filtered water improve skin, hair and health?

Two separate questions — drinking and showering

The question of whether filtered water improves skin, hair and health is actually two separate questions that are frequently conflated in water filter marketing:

1. Does filtered water you drink improve your skin and health? The mechanism here is improved hydration and reduced ingestion of certain compounds.
2. Does filtered water you shower and wash in improve your skin and hair? The mechanism here is topical — what water contacts your skin and hair directly.

The evidence for each is different in strength and character. This article covers both honestly, including what the clinical literature actually shows rather than what water filter marketing typically claims.

Showering — what chlorine and chloramine actually do to skin and hair

This is where the strongest mechanistic evidence exists. Chlorine and chloramine are oxidising disinfectants — that is their function. They kill bacteria by oxidising their cellular structures. They apply the same chemistry, to a lesser degree, to biological material they contact during your shower — including the natural oils (sebum) that protect your skin barrier, and the keratin and lipid structures of your hair.

Skin barrier: Chlorine disrupts the stratum corneum — the outermost layer of your skin — by increasing transepidermal water loss (TEWL). This means your skin loses moisture more rapidly than normal after washing. The result is the post-shower tightness and dryness many people notice. For people with healthy skin and adequate sebum production, this effect is temporary and mild. For people with sensitive skin, eczema, or psoriasis, or for older skin where barrier function is already reduced, the effect can be more significant and cumulative.

Hair: Hair's protective outer layer — the cuticle — is made of overlapping keratin scales. When these lie flat, hair appears shiny and retains moisture well. Chlorine causes these scales to lift and separate, increasing hair porosity (hair absorbs and loses moisture rapidly), leading to frizz, brittleness, and dullness. This is the same mechanism as pool water damage — just at lower concentration, applied daily.

Chloramine: Chloramine (used in Brisbane, Sydney, Adelaide and others) is more chemically stable than free chlorine and harder to remove, but applies similar oxidative chemistry to skin and hair. The damage is more gradual and persistent than free chlorine. Standard shower head filters designed for free chlorine often do not effectively remove chloramine — look specifically for catalytic carbon, KDF-55 media, or vitamin C-based shower filters.

Hard water and eczema — what the clinical evidence actually shows

This is where the evidence is most interesting — and most frequently misrepresented.

A 2021 systematic review and meta-analysis published in Clinical and Experimental Allergy (Jabbar-Lopez et al.) examined all available evidence on hard water and atopic eczema. The findings were:

• There is a positive association between living in a hard water area and atopic eczema (AE) in children. Children in harder water areas are statistically more likely to develop eczema. The association is consistent across multiple studies.
• However, installing a water softener does not reliably improve established eczema. Two randomised controlled trials comparing water softeners to standard care found no significant difference in objective eczema severity scores (EASI). The lesion sizes before and after softening did not change significantly.
• Parents of children with eczema did report subjective improvement (fewer symptoms of itching and dryness) after softening, even when objective measures did not show change. This gap between subjective and objective outcomes is common in dermatology research.

The nuanced interpretation: hard water may play a role in the initial development or triggering of eczema susceptibility, particularly in early childhood. But once eczema is established, the evidence that a water softener alone will significantly improve it is weak. This does not mean softening is useless — it means managing established eczema is more complex than water hardness alone.

Hard water and hair — the evidence is clearer

For hair, the evidence that hard water causes measurable damage is stronger and more consistent than for skin conditions. Calcium and magnesium deposits from hard water accumulate on hair shafts, disrupting the cuticle, blocking moisture from penetrating, and making it progressively harder for products to work effectively. In areas of very hard water — Perth suburbs above 200 mg/L, Adelaide northern suburbs — this accumulation occurs with every wash.

The practical effects people report: dull, flat hair that doesn't respond well to conditioner; buildup that makes hair feel heavy; frizz that doesn't resolve with styling products. These are not imagined — they are consistent with the physical chemistry of calcium and magnesium deposition on keratin fibres.

A chelating or clarifying shampoo (designed to strip mineral buildup) used weekly is a low-cost partial solution without filtration. A whole-home TAC or softening system addresses the problem at the source.

Drinking filtered water — the skin and health connection

The primary way filtered drinking water benefits skin is indirect: better-tasting water is consumed in greater volume, and adequate hydration is one of the clearest contributors to skin moisture and elasticity. This is not a dramatic effect — dehydrated skin does look and feel drier, and well-hydrated skin functions better — but it is real and well-supported.

The secondary mechanism is contaminant reduction. Some compounds in tap water — chlorine, chloramine, disinfection byproducts (THMs and HAAs), trace pharmaceuticals — are ingested when you drink unfiltered tap water. The health significance of these at typical Australian mains water concentrations is actively debated, but for people with specific sensitivities, reducing ingestion of these compounds may have noticeable effects on digestion, skin sensitivity, and general wellbeing.

There is no strong clinical evidence that filtered drinking water directly produces measurable skin or hair improvements in healthy adults with normal water quality. The honest version is: if filtered water tastes better and you drink more of it, your hydration improves and skin benefits follow. That indirect pathway is genuinely valuable — it is just not the dramatic "filtered water transforms your skin" narrative most marketing uses.

What the evidence actually supports — honest summary

Who benefits most from water filtration for skin and hair

The honest answer: those with pre-existing sensitivities and those in high-hardness or high-chlorine areas see the most benefit. Those with normal healthy skin and hair in soft-water areas like Melbourne will notice very little difference.

• People with sensitive skin, eczema, or psoriasis in Perth or Adelaide: High hardness + high chlorine is the combination most likely to cause daily aggravation of skin conditions. A whole-home system addressing both is most justified here.
• People with colour-treated or chemically processed hair: Chlorine accelerates colour fade and chloramine compounds make hair more porous over time. A shower filter or whole-home system meaningfully extends colour treatment intervals.
• People in hard water areas noticing hair dullness or buildup: TAC or softening at the shower addresses mineral deposition on hair. Weekly chelating shampoo is a lower-cost partial alternative.
• People who find tap water taste aversive and drink less as a result: A carbon block filter improving palatability and leading to better hydration has genuine skin benefits via the indirect pathway.
• People with mild asthma or respiratory sensitivity: Reducing chlorine gas inhalation during hot showers is a legitimate benefit of shower filtration.

The people least likely to see meaningful skin and hair improvement from filtration: those in Melbourne or Sydney (soft, lower-chlorine water) with healthy, normal skin. This does not mean filtration is useless for them — taste improvement, contaminant reduction, and appliance protection are all valid reasons. But skin and hair benefits will be modest.

What to install — matched to your situation

For skin and hair, the filtration priority order is:

1. Shower filter or whole-home carbon block (chlorine/chloramine removal): The most direct topical benefit. If you're in a chloramine area (Sydney, Brisbane, Adelaide, most of Melbourne), specify a filter with catalytic carbon or KDF-55 — not just standard GAC carbon.
2. TAC or whole-home softening in hard water areas (Perth, Adelaide north): Addresses hardness deposition on hair and skin. Note: softening alone without carbon filtration does not address chlorine or chloramine.
3. Carbon block drinking water filter: Improves taste → improves hydration → indirect skin benefit. The under-sink or benchtop filter you already drink from.
4. RO only if you have specific compound concerns (PFAS, nitrates, fluoride) — not as a primary skin and hair intervention.