SPF 101: How Often to Reapply Sunscreen and Why It’s Not Just for Summer
Understanding and Avoiding the Top 3 Killers Over 30
When most people think of sunscreen, they think of summer. But protecting your skin from UV damage isn't just a seasonal chore, it’s a year-round investment in your health and appearance. Whether the sun is blazing overhead or hiding behind clouds, ultraviolet (UV) radiation is still at work, gradually breaking down collagen, accelerating aging, and increasing your risk of skin cancer.
We believe that smart sun protection is one of the most impactful daily habits you can adopt, not just for preventing wrinkles, but for preventing disease. We’re diving into the science of SPF, including what ingredients matter, when to apply (and reapply), and why mineral sunscreen is one of the best options for daily use.
Why Mineral Sunscreen Matters Year-Round
UV rays don’t take the winter, or even cloudy days, off. In fact, up to 80% of UV rays can penetrate cloud cover. While summer tends to bring higher UV indexes due to the sun’s position, UV radiation is present every day of the year. UVA rays, which penetrate deeper into the skin, are present at relatively consistent levels all year long and are the primary cause of premature aging and collagen breakdown.
If you’ve ever asked, “Do I need to wear sunscreen when the UV index is 1?” the short answer is yes, especially on areas of skin that are regularly exposed, like the face, neck, and hands. While lower UV index days carry less immediate risk of sunburn, cumulative UV exposure still contributes to long-term skin damage.
What Is a Mineral Sunscreen?
There are two main types of sunscreen: chemical and mineral (also known as physical sunscreen). Understanding the difference is key when choosing the right formula for your skin and lifestyle.
- Mineral sunscreen uses active ingredients like zinc oxide and titanium dioxide to create a physical barrier that sits on top of the skin and reflects UV rays away.
- Chemical sunscreen uses compounds like avobenzone, oxybenzone, or octinoxate to absorb UV rays and convert them into heat, which is then released from the skin.
Mineral vs Chemical Sunscreen: Which Is Better?
Both types of sunscreen offer protection, but mineral sunscreens are increasingly recommended by dermatologists, especially for sensitive skin or post-procedure use. Here's why:
Feature |
Mineral Sunscreen |
Chemical Sunscreen |
Active Ingredients |
Zinc oxide, titanium dioxide |
Avobenzone, oxybenzone, octinoxate, etc. |
How It Works |
Reflects UV rays |
Absorbs and transforms UV rays |
Protection Onset |
Immediate |
Requires 15–20 minutes |
Irritation Risk |
Low |
Higher (can irritate sensitive skin) |
Environmental Impact |
Reef-safe (in most cases) |
Often contains reef-harming ingredients |
Mineral formulas tend to be more stable and are less likely to cause breakouts or allergic reactions. They’re also the only sunscreens approved by the FDA for infants under 6 months.
We offer medical-grade mineral sunscreens that provide broad-spectrum protection without the additives found in many drugstore options. These products are ideal for daily use, especially after treatments like microneedling or laser procedures.
How Often to Reapply Sunscreen
Even the best sunscreen can’t protect you all day without reapplication. Here are the general guidelines supported by dermatology research:
- Reapply every 2 hours when outdoors, even on cloudy days.
- Immediately reapply after swimming, sweating, or towel-drying.
- For indoor use (like sitting near a sunny window or driving), one morning application may be enough, but consider a second if you spend extended time in direct sunlight.
For makeup wearers, reapplication can be tricky. Consider powder-based mineral sunscreens or spray-on formulations to make it easier to reapply without disrupting your routine.
The Role of UV Index in Skin Protection
The UV Index is a numerical scale that ranges from 0 to 11+, indicating the risk of UV exposure. But even on days when the UV index is low (1–2), UVA rays are still present and can silently damage the skin over time. While UVB rays are more intense in the summer and are the primary cause of sunburn, UVA rays penetrate deeper and are associated with aging and skin cancer.
Here’s how the UV Index breaks down:
UV Index |
Risk Level |
Protection Recommendation |
0–2 |
Low |
Daily sunscreen still recommended, especially for the face |
3–5 |
Moderate |
Sunscreen and shade between 10am–4pm |
6–7 |
High |
SPF 30+, seek shade, wear protective clothing |
8–10 |
Very High |
Extra precautions needed—reapply frequently |
11+ |
Extreme |
Max protection needed; avoid sun exposure if possible |
The takeaway? Don’t wait for high UV warnings to protect your skin. Damage accumulates daily, even when it’s not immediately visible.
Why Daily SPF Is an Investment in Your Skin
Sun damage is the leading cause of premature aging, including fine lines, wrinkles, dark spots, and sagging skin. UV exposure also plays a central role in the development of skin cancers, including basal cell carcinoma, squamous cell carcinoma, and melanoma.
By wearing sunscreen daily, you are:
- Preserving collagen and elasticity
- Preventing discoloration and uneven skin tone
- Reducing your future need for corrective aesthetic treatments
- Protecting against skin cancer, the most common form of cancer in the U.S.
This is especially important if you’re undergoing aesthetic treatments or using topical skincare with active ingredients (like retinoids or AHAs), which can increase your skin’s sensitivity to UV rays.
Who Needs Sunscreen? (Hint: Everyone)
While fair-skinned individuals are more prone to sunburn, UV damage affects all skin tones. In fact, skin cancers in people of color are often diagnosed at later stages, making them more dangerous. Regardless of pigmentation, daily SPF is a must.
Sunscreen is also essential for:
- Postmenopausal women experiencing skin thinning and increased UV sensitivity
- Men over 50, the demographic with the highest rate of skin cancer diagnoses
- Teens and young adults looking to prevent early signs of aging
What Physician’s Plan Recommends
We offer physician-selected, mineral-based sunscreens formulated for all skin types, including sensitive and post-procedure skin. Our of our favorite SPF products include:
- Tinted mineral sunscreens that double as a lightweight foundation
- Water-resistant options ideal for outdoor activities
- Antioxidant-enhanced formulas to fight environmental stressors
Not sure which one is right for you? Our team can recommend the best mineral sunscreen for your skin goals, whether you're targeting sun protection, anti-aging, or post-treatment recovery.
The Bottom Line
Daily sun protection is one of the most powerful anti-aging tools available and it’s completely within your control. Whether you’re asking, “What is a mineral sunscreen?” or “How often to reapply sunscreen?” the bottom line is this: protecting your skin from UV damage should be as routine as brushing your teeth.
Don’t wait until summer to think about SPF. By investing in year-round sunscreen use, especially high-quality mineral formulas, you can protect your skin’s health, maintain its youthful appearance, and reduce your risk of cancer, every single day.