Drinking water for clear skin: does it help with spots?
Six studies, one clear picture: water increases stratum corneum hydration, but the effect stops at sebum content. What this means for spots, wrinkles and dry skin.
Drinking water measurably increases the hydration of the stratum corneum. The effect stops at sebum content, which is where acne develops. In 2018, a systematic review by Charité-Universitätsmedizin Berlin screened a total of 216 records and retained six studies. The result: hydration of the outermost layer of skin rose slightly, as did extensibility and elasticity. Signs of dryness and roughness decreased. For sebum content, the link remained unclear.
For dry skin, there is therefore a weak but measurable effect. It was most evident in people who previously drank little. For spots, wrinkles and a clear complexion, there is no evidence. There, other factors are decisive: sebum, hormones and exposure to ultraviolet radiation.
What the studies show
In 2018, five researchers from the Department of Dermatology and Allergy at Charité published the most thorough review of the topic to date. They searched PubMed and Web of Science with no time limit. Of 216 records, 23 full texts remained. Of these, six studies met the criteria. The mean age of the samples ranged from 24 to 56 years.
Their verdict on the overall evidence is clear. In their own words: “Overall the evidence is weak in terms of quantity and methodological quality.” In plain terms: few studies, weak methodology. Nevertheless, the studies from 2006 to 2015 show a consistent pattern.
Additional water increased the hydration of the stratum corneum and the deeper skin layers. The increase was greatest in people who previously drank little. Three findings recur: more hydration in the stratum corneum, less dryness, less roughness. The skin's extensibility and elasticity rose slightly. For three measurements, the picture remained unclear: sebum content, skin pH, transepidermal water loss. Transepidermal water loss refers to the amount of water that evaporates outwards through the skin. In the studies, skin hydration always means the hydration of the stratum corneum, measured at the surface.
Research still does not know the biological mechanism, and the 2018 review names two further open questions. According to the authors, it remains unclear whether the link also applies to older people. It is equally unclear whether drinking more reduces the signs of dry skin.
The four studies compared
| Study | Participants | Additional intake | Result |
|---|---|---|---|
| Charité 2018, review | six studies from 216 records | varied | Higher stratum corneum hydration, no clear link for sebum content |
| Palma 2015, Lisbon | 49 women, mean age 24.5 years | 2 litres over 30 days | Superficial and deep hydration changed significantly, most strongly in the women who drank little |
| Williams 2007, Hamburg | 93 people, 86 completed | 2.25 litres over four weeks | Mineral water and tap water had opposite effects |
| Mac-Mary 2006, Besançon | 80 people with dry skin, mean age 56 | Additional mineral water | Hydration, water loss and microrelief improved |
The 2015 Lisbon study divided 49 women according to their previous fluid intake. 38 were below 3,200 ml a day, 11 above. Two extra litres over 30 days significantly changed hydration on the face, arm and leg. The change was strongest in the group with the lower initial intake. The dependence on the baseline value is the most robust single finding from all six studies.
Why tap water and mineral water produced opposite results
The 2007 Hamburg study is cited as evidence that water makes the skin thicker and denser. Its figures only half support this claim. 93 people drank 2.25 litres a day for four weeks. 53 of them drank mineral water, 40 tap water. In the mineral water group, skin density fell significantly, while thickness rose slightly but not significantly. In the tap water group, skin density rose significantly and thickness fell significantly. Both values therefore moved in opposite directions, depending on the type of water.
One part of the claim stands up to scrutiny. Among the people who drank mineral water and previously had a low fluid intake, skin thickness increased significantly. The study was exploratory in design, a before-and-after measurement without a control group. The authors themselves call for randomised, controlled, double-blind follow-up studies, but none have been carried out since 2007. The differences between the two types of water are covered in detail in the comparison Tap water or mineral water.
Does drinking water help with spots?
To this day, there is no controlled study on the link between fluid intake and spots. The 2018 Charité review did at least examine the measurement that matters: the sebum content of the skin. That is precisely where the link with fluid intake remained unclear. Sebum is the variable on which acne depends, and the following process shows why.
How a spot forms
The Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen (IQWiG, Institute for Quality and Efficiency in Health Care) describes three steps. First, the body produces more androgens, i.e. male hormones, during puberty. Second, the androgens stimulate the sebaceous glands to produce more. Third, a keratinised layer forms at the opening of a sebaceous gland. The result is clogged pores: the sebum builds up and forms a blackhead. If bacteria cause the blackhead to become inflamed, a spot develops.
Three variables drive this process: hormones, the amount of sebum and keratinisation at the gland opening. Sebum content is precisely the value for which the Charité review found no clear link with fluid intake. The mechanism therefore breaks down at the decisive point. More water affects the hydration of the stratum corneum, but sebum production remains unaffected.
What is proven to work against acne
IQWiG names three groups of active ingredients as effective: benzoyl peroxide, antibiotics, retinoids. Treatment requires months to years of patience. For skin care, the institute recommends oil-in-water emulsions or hydrogels and advises against greasy creams. On IQWiG's acne page, as of 12 November 2025, fluid intake is not mentioned anywhere. Severe or scarring acne should be treated by a dermatologist.
The one proven link between drinking and skin
On diet, IQWiG writes: studies mostly show no link between any particular diet and acne. The institute names one possible exception: carbohydrate-rich foods that cause blood sugar to rise quickly. This means there is a lever that works through drinks. Replacing soft drinks with water reduces the amount of sugar consumed.
The benefit then comes from the sugar left out, not from the water drunk. The difference between the two approaches determines what you can expect. Two litres of water in addition to soft drinks do not change the blood sugar curve. Two litres of water instead of soft drinks do.
Clear skin from water alone?
Clear skin, beautiful skin and healthy skin are three distinct goals. Clear skin means the absence of blemishes. Beautiful skin is an aesthetic judgement, healthy skin a medical finding. Beauty magazines link water to all three goals. Of these, the measurements from the six studies cover three variables: hydration, extensibility, roughness. The time frame of the question also reveals a misunderstanding. Measurements were taken after 15 and 30 days. Blemishes were not part of the measurement protocol in any of the studies. A clear complexion in two days lies beyond what data from 15 and 30 days can show.
Water is the body's basic supply. It is needed to regulate breathing and body temperature, and for blood pressure and pulse. Adequate fluid intake is the prerequisite for the skin to function normally, but that does not make it a treatment. The difference between refuelling and tuning sums it up.
Drinking water against wrinkles
Wrinkle formation depends on a factor that has nothing to do with drinking. A dermatological study of 298 women aged between 30 and 78 compared 157 sun-seeking participants with 141 who avoided the sun. Twelve trained assessors evaluated 22 clinical parameters using standardised photographic scales. According to the study, ultraviolet radiation (UV radiation) accounts for around 80% of the visible signs of ageing on the face.
The study of 298 women distinguishes between two types of ageing. Pigmentation spots were strongly linked to sun exposure. Sagging of the tissue followed chronological ageing and hardly differed between the groups. Both processes affected wrinkles and skin texture.
This leaves fluid intake only a narrow corridor. The Charité review found a slight increase in extensibility and elasticity. A more hydrated stratum corneum can smooth out fine dryness lines. Water, however, has no effect on wrinkle depth caused by years of UV exposure. When it comes to wrinkle depth, sun protection is the lever, not the water bottle.
Before-and-after photos and self-experiments
The four robust studies from 2006 to 2015 used three measurement methods: corneometry, ultrasound, dermatological grading under standardised lighting. They measured hydration in the stratum corneum and thickness in fractions of a millimetre. Such variables remain invisible in a mobile phone photo. Before-and-after pictures from self-experiments are therefore of little use as evidence.
A photo shows four other variables: light, angle, time of day, the condition of the skin at that moment. Anyone who drinks more for 30 days usually changes other things in the same period too: sleep, sugar, alcohol, sun, skincare products. The visible effect therefore cannot be attributed to any single change. That is exactly why the authors of the Hamburg study call for controlled double-blind trials.
Nevertheless, a realistic expectation can be stated. If your intake has so far been well below your own requirement, you can expect more hydration in the stratum corneum after two to four weeks. On top of that comes less roughness. If you already meet your requirement, you will look in vain for any further effect.
Drinking too little: what the skin shows
IQWiG names five early signs of fluid deficiency: thirst, difficulty concentrating, headaches, lethargy and tiring quickly. In cases of moderate to severe deficiency, these are joined by dry mucous membranes, dizziness after standing up quickly and a racing heart. Doctors then check for persistent skin folds, among other things. If you lift a fold of skin and it stays standing, this indicates dehydration.
The persistent skin fold belongs to emergency medicine, not to cosmetics. It occurs with a water deficit that affects the circulation. With 1.2 instead of 1.4 litres on a given day, the skin remains unaffected. Four groups are particularly at risk: older people with a reduced sense of thirst, infants, young children and people with dementia or swallowing difficulties.
Dry skin: lipids matter more than fluid intake
Dry skin mostly originates in the barrier, less often in the body's water balance. The stratum corneum retains moisture via lipids, i.e. skin fats that bind the cells together like mortar. If the lipids are missing, water evaporates outwards, regardless of how much you drink. Four influences attack the lipid layer: hot showers, surfactant-based cleansers, dry heated air, cold.
For dry skin, the order is therefore clear: first care for the barrier, then check your fluid intake. A moisturiser replaces the missing lipids from the outside. Here, the research supports drinking as a complement. The authors of the 2006 Besançon study describe it as a “complementary cosmetic approach”. In plain terms: an additional cosmetic approach.
How much water the body needs
1,410 ml from drinks and 2,600 ml of total water intake a day: this is the reference value for adults aged between 25 and 51. It was set by the Deutsche Gesellschaft für Ernährung (DGE, German Nutrition Society). The requirement is made up of three parts, and drinks are the largest of these. Solid food also supplies water, and burning nutrients produces oxidation water.
| Age | Drinks | solid food | Oxidation water / total |
|---|---|---|---|
| 19 to under 25 years | 1,470 ml | 890 ml | 340 ml 2,700 ml |
| 25 to under 51 years | 1,410 ml | 860 ml | 330 ml 2,600 ml |
| 51 to under 65 years | 1,230 ml | 740 ml | 280 ml 2,250 ml |
| 65 years and older | 1,310 ml | 680 ml | 260 ml 2,250 ml |
Around 1.4 litres of drinks a day are therefore enough for a middle-aged adult to meet the reference value. The widespread recommendation of three litres is above this. The six studies provide no skin-related reason to aim for it. According to the DGE, the requirement is higher with high energy expenditure, heat, dry cold air, high table salt consumption and high protein intake. The same applies with fever, vomiting and diarrhoea. Sport and summer push the value up; a skin goal does not. The guide How much water should I drink works out your personal water requirement with its requirement calculator.
There is also an upper limit, even though the kidneys reliably excrete any excess. With very large amounts in a short time, the sodium level in the blood falls. If it falls too far, water intoxication results. This becomes relevant from several litres within a few hours.
Which drinks cover your needs
In the fluid balance, every unsweetened drink counts equally: water, unsweetened tea, juice spritzers in a ratio of 1 part juice to 3 parts water. Lemon water and water flavoured with fruit or herbs change the taste without adding sugar. Water-rich foods contribute a further 860 ml a day, according to the DGE's calculation for middle-aged adults. Six examples consist mostly of water: cucumber, tomato, courgette, pepper, melon, berries.
Sweetened drinks are the only point with a plausible link to the skin, namely via blood sugar. Three groups of drinks supply sugar in a rapidly available form: soft drinks, energy drinks, sweetened iced teas. Replacing them targets exactly the point that IQWiG names as a possible exception in the question of diet and acne.
That leaves taste as a practical hurdle. Anyone who avoids tap water because of a chlorine or metallic taste drinks measurably less of it. This is exactly where an activated carbon filter comes in. According to the manufacturer, the Active cartridge is designed to tackle three problem factors: chlorine, pollutants, off-flavours. It thus improves the taste of drinking water. This is an argument about drinking behaviour, not a skin promise. The guide Chlorine in drinking water explains how much chlorine German drinking water actually contains. How good water quality is overall is covered in Is tap water healthy? and in Our tap water.
Conclusion: the effect stops at the stratum corneum
Six studies from 216 screened records demonstrate three effects: more hydration in the stratum corneum, less dryness, less roughness. The effect is most pronounced where fluid intake was previously low. There is no evidence for spots and wrinkles, because sebum content and UV damage depend on other levers. Around 80% of visible signs of ageing are due to sun exposure.
In practice, this results in four steps: drink 1,410 ml a day, use sun protection against wrinkles. Add to that lipid care for dry skin and dermatological active ingredients for acne. If the taste stops you from drinking, that is exactly where you can take action.
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Frequently asked questions
Does drinking water improve your skin?
Partly. Across six studies, the 2018 Charité review found more hydration in the stratum corneum. It also found less dryness and roughness and slightly higher elasticity. The effect was strongest in people with a previously low fluid intake. The authors rate the evidence overall as weak in both quantity and methodological quality.
Does drinking water help with spots?
There is no evidence. Acne develops through androgens, increased sebum and keratinisation at the sebaceous gland opening. For sebum content, the Charité review found no clear link with fluid intake. IQWiG names benzoyl peroxide, antibiotics and retinoids as effective.
How long does it take for the skin to change?
The studies took measurements after 15 and 30 days. In the 2015 Lisbon study, hydration changed significantly within 30 days. Participants drank an extra two litres. A clear complexion in two days lies beyond what the data can show.
Does drinking water help against wrinkles?
For fine dryness lines, a small effect is plausible, because extensibility and elasticity increased slightly in the studies. For wrinkles caused by ageing, the finding of a study of 298 women applies: ultraviolet radiation accounts for around 80% of the visible signs of ageing on the face.
Are three litres a day better for the skin?
For adults aged between 25 and 51, the DGE specifies 1,410 ml from drinks and 2,600 ml of total water intake a day. There are no studies showing that three litres lead to a better complexion. The requirement is higher with heat, sport, dry air, high salt or protein intake, and with fever, vomiting and diarrhoea.
Can the skin absorb water from the outside?
The six included studies examined only water that was drunk. For the skin, what matters most when showering and bathing is what happens to the lipid layer. Hot water and surfactants dissolve out fats and thus increase water loss to the outside.
Does it make a difference to the skin whether you drink tap water or mineral water?
The 2007 Hamburg study found opposing results. In the mineral water group, skin density fell and thickness rose slightly. In the tap water group, density rose and thickness fell. Both occurred in an exploratory study without a control group. No recommendation for either type of water follows from this.
Can you drink too much water?
Yes, but only from several litres within a few hours. The kidneys normally excrete any excess. If very large amounts cause the sodium level in the blood to fall too sharply, water intoxication results. It must be treated by a doctor.
Sources
- Akdeniz M, Tomova-Simitchieva T, Dobos G, Blume-Peytavi U, Kottner J: Does dietary fluid intake affect skin hydration in healthy humans. A systematic literature review. Skin Research and Technology 2018, 24(3), 459 to 465
- Palma L, Marques L, Bujan J, Rodrigues L: Dietary water affects human skin hydration and biomechanics. Clinical, Cosmetic and Investigational Dermatology 2015, 8, 413 to 421
- Williams S, Krueger N, Davids M, Kraus D, Kerscher M: Effect of fluid intake on skin physiology, distinct differences between drinking mineral water and tap water. International Journal of Cosmetic Science 2007, 29(2), 131 to 138
- Mac-Mary S, Creidi P, Marsaut D et al.: Assessment of effects of an additional dietary natural mineral water uptake on skin hydration in healthy subjects. Skin Research and Technology 2006, 12(3), 199 to 205
- Flament F, Bazin R, Laquieze S et al.: Effect of the sun on visible clinical signs of aging in Caucasian skin. Clinical, Cosmetic and Investigational Dermatology 2013, 6, 221 to 232
- Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen: Acne, as of 12 November 2025
- IQWiG: Fluid deficiency (dehydration), as of 18 October 2023
- Deutsche Gesellschaft für Ernährung: Reference values for water
