The Truth About Dehydration — And Why Your Skin Feels It First

If you’ve ever looked in the mirror and noticed dullness, fine lines, or tight, flaky skin, dehydration might be the silent culprit. Unlike dry skin, which is a skin type, dehydration is a condition that can affect any skin type, at any age.

While dehydration is often temporary, repeated or chronic dehydration can contribute to premature ageing, including fine lines, wrinkles, and a weakened skin barrier.

But how much water do you really need? And how do factors like coffee, alcohol, or weather change that number?

Let’s dive in.

What Is Dehydration, Really?

Dehydration happens when your body is losing more fluids than it’s taking in. For your skin, that means less water is available in the upper layers, which leads to:

• Dullness and lack of glow
• Tightness or itchiness
• Fine lines are becoming more visible
• A crepey or papery texture
• Makeup sitting unevenly or flaking

Even oily or acne-prone skin can become dehydrated.



How Much Water Do You Actually Need?

The old "8 glasses a day" rule is a good start, but your needs depend on:

• Body weight: A common guide is 33ml per kg of body weight
• Activity level: Exercise = more sweat = higher water loss
• Climate: Hot or dry weather increases water needs
• Food intake: If you eat water-rich foods (like cucumber, watermelon, soups), your fluid needs may be slightly lower
• Rough guide: 2.5 to 3.5 litres per day for most adults in temperate climates

Coffee & Alcohol: What Do They Really Do?

Coffee

Caffeine is a mild diuretic, but research shows moderate coffee intake doesn’t significantly dehydrate you. However, if you’re having more than 3 cups a day, you should offset it by drinking extra water.



Rule of thumb

 Drink one extra glass of water for every cup of coffee.



Alcohol

Alcohol is much more dehydrating. It increases urine output and inhibits the hormone (ADH) that helps your body retain water.

That "wine glow" the night of? It’s usually inflammation. The real effects show up as dullness and dehydration the next day.

Rule of thumb

One glass of water for every alcoholic drink, and extra the next day.



Other Dehydration Triggers

• Air travel: Low humidity in planes draws moisture from your skin
• Heaters and air conditioning: Both dry out the air, pulling water from your skin
• Salt and sugar: Diets high in processed foods, sodium, or sugar can contribute to fluid imbalance
• Stress: Cortisol and adrenaline impact your hydration levels and skin barrier function



How Dehydration Affects Aesthetic Results

Whether you’re having dermal filler, skin boosters like Profhilo, or biostimulator treatments, dehydration can impact both the appearance and longevity of your results:

Volume & Plumpness

• Filler relies on the skin's water content to appear plump and natural.
• Dehydrated skin may make results look flat, crepey or less visible.



Skin Quality Treatments

• Skin boosters, microneedling, and PRP need healthy hydration levels to support healing and glow.
• Dehydrated skin may heal more slowly or show reduced results.

Longevity of Results

• Hyaluronic acid-based fillers draw and hold water.
• If you're not hydrated, the filler can't perform as well and may break down faster.

Healing and Recovery

• Dehydrated skin = slower healing and a higher risk of flaking or irritation post-treatment.

Pro tip: Hydrate well before and after your treatment for optimal, longer-lasting results.

How to Tell If You’re Dehydrated

• Skin feels tight or sensitive
• Fine lines are more pronounced than usual
• Skin looks dull, especially in the afternoon
• You feel tired, foggy, or unusually thirsty

So... What Can You Do?

Internally:

• Aim for 2.5–3.5L water/day, adjusting for caffeine, alcohol, activity & climate
• Include water-rich foods: cucumber, zucchini, citrus, berries, soups
• Use electrolytes if you’ve been sweating a lot

Externally:

• Use a humectant serum (like hyaluronic acid) under your moisturiser
• Apply moisturiser to damp skin to seal in hydration
• Avoid over-washing or stripping cleansers
• Try professional treatments that boost skin hydration and barrier repair

Final Thoughts

Drinking more water isn’t a magical fix — but when your skin is dehydrated, it can absolutely make a difference.

Hydration not only supports healthy skin function but also enhances the results of your cosmetic treatments.



Combine proper hydration with skincare that supports your barrier, and your skin will feel (and look) more plump, radiant, and comfortable.

Ready for a skin reset?

Explore treatments that support hydration, skin barrier repair, and overall skin health at Immortal Cosmedical, Skin & Cosmetic Clinic in the Southern Highlands.

Book your personalised consultation today.