Sunscreen (SPF 50/50+): Why It Matters, How To Use It, and What To Expect

Introduction

Daily sunscreen is the foundation of skin health and cosmetic improvement. It prevents the chain of damage that causes wrinkles, rough texture, broken capillaries and blotchy pigment. Sunscreen also lowers the burden of sun‑induced skin disease over a lifetime. In Australia, therapeutic sunscreens are regulated products and must meet strict performance tests before sale. ¹ ²

When used correctly, sunscreen is the single step that slows the look of ageing skin while making every other treatment work better and more safely. In a randomized Australian study, people assigned to daily sunscreen developed significantly less photoageing than those who applied it only when they felt they needed it. ³

Category and product type

Sunscreen is an over‑the‑counter treatment in Australia. Primary sunscreens are regulated as therapeutic goods and must be listed or registered on the Australian Register of Therapeutic Goods. Labels such as “SPF 50+” and “broad‑spectrum” have to be proven by laboratory testing. ¹

What sunscreen prevents and who benefits

Sunscreen reduces the ongoing injury from the sun that leads to fine lines, roughness and uneven colour. It prevents ultraviolet light from triggering pigment flares and from switching on enzymes that break down collagen. Everyone benefits: fair and darker skin tones; people with melasma or redness‑prone skin; and anyone who has had cosmetic procedures or is planning them. ²⁴

Australia has some of the highest ultraviolet levels in the world. Consistent protection is therefore not only a cosmetic step but also an important health habit to reduce the lifetime burden of sun damage. ⁵

How sunscreen works (in plain English)

Sunlight that ages and spots the skin is made of two main types of ultraviolet light. Ultraviolet‑B mainly affects the surface of the skin and causes sunburn. Ultraviolet‑A penetrates more deeply and accelerates collagen breakdown and uneven colour. A broad‑spectrum product protects against both types. ² ⁴

Sunscreen formulas use either mineral filters or organic filters. Mineral filters such as zinc oxide and titanium dioxide sit on the surface and reflect or scatter ultraviolet light; organic filters absorb the energy of ultraviolet light and release it as a tiny amount of heat. Both approaches work when the product is applied in the right amount and reapplied as needed. ¹ ²

How to use sunscreen so it works

Amount: Use a generous layer. A practical guide is about half a teaspoon for the face and neck combined. For the whole body in swimwear, a shot‑glass amount is a useful estimate. These amounts match how products are tested in the laboratory. ²

Timing: Apply in the morning to clean, dry skin. If you will be outdoors, apply at least twenty minutes before sun exposure. Reapply every two hours while you remain outdoors or after swimming, sweating or towelling. ²

Layering with skincare and makeup: In the morning, apply any antioxidant serum first, then moisturiser if you use one, then sunscreen. Let sunscreen set before makeup. Do not dilute sunscreen by mixing other products into it in your hand, because this reduces the protective dose. ²

Clothing and shade: Think of sunscreen as one part of a protection system that also includes a brimmed hat, protective clothing, shade and sunglasses. Together they provide better and more reliable protection than sunscreen alone. ²⁵

What to expect over time

Immediate: protection begins as soon as the product is on the skin. Many people notice less end‑of‑day redness and tightness right away. ²

Four to eight weeks: tone looks steadier with fewer new dark spots because daily ultraviolet‑triggered inflammation is reduced. ³

Three to six months and beyond: texture looks smoother and very fine lines are less obvious because ongoing collagen breakdown has been reduced. These improvements continue as long as daily use continues. ³

Common adverse effects and simple fixes

Stinging or eye watering can occur with some textures. Switching to a different base or to mineral‑dominant filters usually helps. Keep a small margin below the lower lash line to avoid migration into the eyes. ²

Breakouts can follow from very occlusive creams in hot weather. Choose lightweight gels or fluid formulas labelled non‑comedogenic. ²

White cast can occur on deeper skin tones with some mineral formulas. Modern micronised or tinted options blend more naturally while maintaining high protection. ²

Key cautions and special situations

Sensitive or post‑procedure skin often tolerates fragrance‑free, mineral‑dominant formulas better. Apply by patting rather than rubbing while the skin heals, and follow any specific aftercare your clinician provides. ²

Infants and young children should be protected with shade, clothing and hats first. Use small amounts of gentle sunscreen on exposed areas when needed, and reapply after water play. ²

Indoor daylight and window exposure still include the type of ultraviolet light that ages the skin. If the daily ultraviolet index is three or above, sunscreen remains useful even on routine indoor days with incidental outdoor time. ² ⁵

Choosing the right formula for your skin

For melasma and post‑inflammatory dark marks, pick a reliable broad‑spectrum product and be disciplined about reapplication. Many people prefer cosmetically elegant, fast‑setting formulas or tinted products that blend well with makeup. ²

For redness‑prone or easily irritated skin, select fragrance‑free products and consider mineral‑dominant filters. Trial a small area first if you are very reactive. ²

For oily or acne‑prone skin, look for lightweight, non‑comedogenic fluids that set dry. Avoid rich occlusive balms during hot, humid weather. ²

Evidence at a glance

Australia regulates therapeutic sunscreens through a national framework that sets how sun protection factor and broad‑spectrum claims are tested and labelled. ¹

Public health guidance in Australia explains how much to apply, how often to reapply, and how to combine sunscreen with hats, clothing, shade and sunglasses for best results. ² ⁵

A randomized Australian study demonstrated that daily sunscreen use slows measurable skin ageing compared with intermittent use. ³

Global health agencies emphasise the importance of reducing ultraviolet exposure to lower skin damage across populations. Sunscreen is one part of that strategy alongside behaviour and clothing. ⁶

Sources

Therapeutic Goods Administration (TGA) 2023, Australian Regulatory Guidelines for Sunscreens (ARGS) V3.0 May 2023, Department of Health and Aged Care, Canberra. (Viewed 10 November 2025), https://www.tga.gov.au/sites/default/files/australian-regulatory-guidelines-for-sunscreens.pdf ↩
Cancer Council Australia 2025, About sunscreen & SunSmart steps (application, re-application and protective behaviours), Cancer Council, Sydney. (Viewed 10 November 2025), https://www.cancer.org.au/cancer-information/causes-and-prevention/sun-safety/about-sunscreen ↩
Hughes M C B, Williams G M, Baker P & Green A C 2013, Sunscreen and prevention of skin aging: a randomized trial, Annals of Internal Medicine, 158(11):781–790. https://pubmed.ncbi.nlm.nih.gov/23732711/ ↩
Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) 2024, Sun protection and sunscreen guidance, ARPANSA, Yallambie. (Viewed 10 November 2025), https://www.arpansa.gov.au/understanding-radiation/radiation-sources/more-radiation-sources/sun-protection-sunscreen ↩
Cancer Council Australia 2025, UV Index, Cancer Council, Sydney. (Viewed 10 November 2025), https://www.cancer.org.au/cancer-information/causes-and-prevention/sun-safety/uv-index ↩
World Health Organization (WHO) 2023, Ultraviolet radiation and health – factsheet, WHO, Geneva. (Viewed 10 November 2025), https://cdn.who.int/media/docs/default-source/radiation/intersun-global-project-countries/optical-2024-australia.pdf?sfvrsn=d7924a59_2 ↩

Disclaimer for Newcastle Cosmetic Doctor Policies & Procedures

The policies and procedures contained within this document are the exclusive property of Newcastle Cosmetic Doctor and are provided for internal clinical governance and educational purposes only. These materials represent the internal operational framework, safety standards, and evidence-based protocols developed and implemented by Dr. Bart John Scanlon and the Newcastle Cosmetic Doctor team. They are designed specifically for use within Newcastle Cosmetic Doctor and reflect our clinic’s own professional standards, risk assessments, and compliance obligations under Australian law and regulatory authorities. External individuals, practitioners, or organisations must not copy, reproduce, distribute, or rely upon these materials, in whole or in part, for their own clinical, commercial, or educational use without prior written consent from Newcastle Cosmetic Doctor. These materials do not constitute medical, legal, or professional advice and are not intended to be adopted as official protocols or procedures by any other entity. Any external use or adaptation must be independently reviewed and modified to meet the relevant laws, guidelines, and standards applicable to the user’s own jurisdiction, scope of practice, and facility operations. Newcastle Cosmetic Doctor and Dr. Bart Scanlon accept no liability for any loss, injury, or damage arising from the unauthorised use, reliance upon, or misinterpretation of this material.