Key takeaways
- Sun damage, called photoageing, is the main avoidable cause of lines, rough texture and spots.
- UVA reaches the deeper skin and passes through window glass, so indoor days still count.
- Daily broad-spectrum sunscreen slowed skin ageing in a randomised trial.
- Darker skin still ages from sun; visible light also worsens pigmentation in Indian skin.
- Most people use far too little sunscreen. For the face, use at least a teaspoon.
How does sun actually age the skin?
People think of the sun as something that tans or burns. The ageing part happens quietly, deeper down.
Sunlight has UVB, which mostly affects the outer skin and causes burning, and UVA, which goes deeper. Research on facial ageing describes UVA damaging the dermis mainly through reactive oxygen species, unstable molecules that injure cells and fibres. Over years this leads to:
- Weaker collagen. Sun-damaged skin shows chronic low-grade inflammation, and the cells that make collagen produce less of it.
- Abnormal elastin. Elastin clumps into a disorganised material, a change called solar elastosis. Skin loses its spring and looks leathery or crepey.
- Uneven pigment. Some areas form sun spots while others lose colour.
The American Academy of Dermatology calls UVA the "aging rays" and notes that they pass through window glass. So sitting by a window at work or in the car is still exposure.
Does sunscreen really prevent ageing? What is the evidence?
Yes, and this is one of the few anti-ageing claims backed by a proper trial.
In Nambour, Australia, researchers randomly assigned 903 adults under the age of 55 to use broad-spectrum sunscreen every day or as they normally would. After about four and a half years, skin ageing was 24% less in the daily sunscreen group. The daily group showed no detectable increase in skin ageing over the trial. The same study gave some people beta-carotene supplements, and those had no overall effect on skin ageing.
See, what happens is, people spend thousands on serums and skip the one step that has this kind of evidence. That is very important to understand. If you do only one thing for your face, do this.
Does Indian skin need sunscreen?
People with darker skin burn less easily, and skin cancer is less common, but the World Health Organization is clear that darker-skinned people also develop skin cancers. More relevant for anti-ageing:
- UVA reaches the dermis in every skin colour, so collagen damage still happens.
- The American Academy of Dermatology notes that visible light can increase hyperpigmentation, particularly in darker skin tones. That is why tan, melasma and patchy pigment are such common concerns in Mumbai and Thane.
- For this reason, the AAD suggests a tinted, broad-spectrum sunscreen of SPF 30 or higher for darker skin.
What should I look for, and how much do I use?
| What to check | What it means |
|---|---|
| SPF 30 or higher | SPF 30 blocks about 97% of UVB, according to the AAD. Higher numbers block slightly more; none block all UVB |
| Broad spectrum | Protects against both UVA and UVB |
| PA rating (on many Indian and Asian products) | A UVA protection grade; more plus signs means more UVA protection |
| Tinted | Helps with visible light, useful for pigment-prone Indian skin |
| Texture you will actually wear | Gel or fluid for oily skin in humid months; cream for dry skin in winter or AC |
Amount. The AAD advises at least one teaspoon for the face. Most people use a pea-sized dot, which gives a fraction of the labelled protection.
Reapplying. Outdoors, reapply about every two hours and after sweating. In Mumbai's humid months, a sunscreen stick or powder sunscreen over makeup can make this practical.
When. The WHO recommends sun protection whenever the UV index is 3 or above. In much of India, that is most of the daylight hours for most of the year. UV can still be high on cloudy days, including the monsoon.
What else protects your skin from sun?
Sunscreen is one layer. The others are simple:
- Shade during the middle of the day
- A wide-brimmed hat or umbrella when walking, which is very normal in India and very useful
- Sunglasses with UV protection, which also help the skin around the eyes
- Covering up on two-wheelers, where the face and arms are exposed for long stretches
A simple daily sun routine for Mumbai and Thane
- Morning: apply a teaspoon of broad-spectrum, tinted SPF 30 or higher to the face and neck after your moisturiser, every day, including work-from-home days.
- Before stepping out: add the ears, back of the neck and hands, which are often forgotten.
- Midday, if outdoors: reapply, or use a stick over makeup.
- Monsoon: keep going. A sweat-resistant gel is easier to wear in the humidity.
- Evening: wash it off gently. Heavy scrubbing is not needed.
Why sunscreen matters even more after treatment
Normally I tell people that sunscreen protects not only their skin but also their treatment. After a peel or laser, skin is more sensitive and more prone to pigment. Collagen-building treatments like radio frequency or HIFU work slowly over months, and daily sun damage works against them. Anti-wrinkle injections do nothing for sun spots. So whatever else you do, protection stays.
How we approach this at Dr Tvacha
In the Long Game Anti-ageing Plan, protect is the second step, straight after the assessment, and it never stops. At our centres in Thane, Andheri, Bandra and Dahisar, we will look at your skin type, pigment and routine and suggest a sunscreen texture you will actually use every day. Often that is the most useful part of the visit. You can read about the Long Game Anti-ageing Plan or how this fits the way skin ages.
Frequently asked questions
Can sunscreen reverse existing sun damage?
Sunscreen mainly prevents further damage. In the Nambour trial, daily users showed no detectable increase in skin ageing over four and a half years, which tells you how much ongoing damage it stops. Existing lines, spots and texture usually need other treatments, such as retinoids, peels or lasers, and those work far better when sunscreen is protecting the skin every day.
Do I need sunscreen if I stay indoors?
If you sit near windows or travel by car, yes. UVA passes through glass, and the American Academy of Dermatology calls it the ageing ray. If you are genuinely away from windows all day, the need is lower, but most people in Indian cities have more daylight exposure than they think. Applying it every morning is the simplest habit.
Is SPF 50 much better than SPF 30?
Not much. The American Academy of Dermatology says SPF 30 blocks about 97% of UVB rays and higher numbers block slightly more. No sunscreen blocks all of it. Using enough and reapplying matters far more than a higher number. Choose broad spectrum, SPF 30 or above, and a texture you will not skip.
Why is tinted sunscreen suggested for Indian skin?
Visible light, not just ultraviolet, can worsen pigmentation, especially in darker skin tones, according to the American Academy of Dermatology. Tinted sunscreens add pigment that helps cover this visible-light part. For people prone to tan, melasma or dark patches, this extra cover can make a real difference over time.
Do I need sunscreen on cloudy or monsoon days?
Yes. The World Health Organization notes that UV levels are highest under clear skies but can still be high when there is cloud cover. In Mumbai and Thane, the monsoon sky often looks dull while UV is still reaching your skin. Keep the habit going all year, and choose a lighter, sweat-resistant texture for the humid months.
Written by
Dr Amit KarkhanisAesthetic Physician · MBBS, Dip. Dermatology (UK) · Reg. No. 2001/02/1124Founder of Dr Tvacha, practising in Thane since 2005. Leads the weight loss and hair programmes.
Sources
- Sunscreen and prevention of skin aging: a randomized trial (Annals of Internal Medicine, 2013)
- Sunscreen FAQs (American Academy of Dermatology)
- Ultraviolet radiation (World Health Organization)
- The Science and Theory behind Facial Aging (Plastic and Reconstructive Surgery Global Open, 2013)
This article is for general education and does not replace a consultation. Medicines and treatments are prescribed only after a doctor's assessment. Last reviewed 25 October 2026.