Why Sunscreen Should Be Your #1 Skincare Step

Written by Rosalie Orrostieta, MSN, APRN, FNP-C
Medically Reviewed for Accuracy and Safety by Rosalie Orrostieta, MSN, APRN, FNP-C
Last Updated: October 09, 2025

As the founder of one of the best medical spa in Sarasota, my world revolves around skin. I spend my days helping clients achieve their goals, clearing acne, softening lines, and restoring that beautiful, healthy glow.

I absolutely love the advanced treatments we have today. From transformative lasers to collagen-boosting microneedling, the results we can achieve are incredible. But I am always telling my clients a simple, foundational truth:

You can invest in the most expensive serums, retinols, and procedures in the world. But if you are not using sunscreen, every single day, you are not just slowing your progress, you might be actively reversing it.

It’s the least glamorous product on your shelf, isn’t it? It’s not in a flashy vial. It doesn’t promise to “reverse” or “transform” overnight. But I’m here to tell you why that humble bottle of SPF is, without a doubt, the most powerful and important skincare step you can take.

It’s not just about beauty. It’s about your health.

Key Takeaways

• Health First: Sunscreen is your #1 tool for preventing skin cancer. The Skin Cancer Foundation reports that daily use of just SPF 15 can cut your melanoma risk by 50%.
• The Best Anti-Aging: The sun is responsible for up to 90% of visible skin aging. Sunscreen is the most effective anti-aging product you can buy, period.
• Protects Your Investment: Sunscreen is non-negotiable after any medical aesthetic treatment (like lasers or peels) and stops the sun from undoing the work of your other products (like retinol).

The #1 Reason: Sunscreen is a Critical Health Tool

Before we talk about wrinkles or dark spots, we have to talk about the most important thing: your health. This is the part of my job as a medical professional that I take most seriously.

Your Non-Negotiable Defense Against Skin Cancer

The facts are stark, and we need to be clear about them. The sun’s ultraviolet (UV) radiation is a proven human carcinogen, in the same class as tobacco.

When that radiation hits your unprotected skin, it damages the DNA in your skin cells. Your body is amazing and can repair some of this damage, but over time, the damage wins. Those mutations can grow out of control, leading to skin cancer.

This isn’t a “small risk” or a “far-off” problem. The data is sobering.

• The Skin Cancer Foundation states that 1 in 5 Americans will develop skin cancer by the age of 70.
• The American Cancer Society estimates that in 2025 alone, about 104,960 new melanomas the deadliest form of skin cancer will be diagnosed in the U.S.

Here is the good news. This is, in large part, preventable. The power is truly in your hands every morning.

A landmark study showed that regular daily use of an SPF 15 or higher sunscreen reduces your risk of developing melanoma by 50 percent.

Fifty percent! Show me a serum that can do that. This isn’t a beauty claim; it’s a critical health intervention.

Understanding the Threat: UVA vs. UVB

To understand why “Broad-Spectrum” is so important on your sunscreen bottle, you need to know your enemy.

• UVB (Burning Rays): These are the rays that cause sunburn. They are powerful and directly damage the skin’s surface. The good news? They don’t penetrate glass, so you’re mostly safe from them indoors.
• UVA (Aging Rays): These are the silent, sneaky ones. UVA rays penetrate deeply into your skin, where they destroy the collagen and elastin that keep it firm. What’s worse? UVA rays pass right through clouds and window glass.

This is why I’m so insistent with my clients. They’ll say, “But Rosalie, I work in an office!” or “It’s cloudy and raining today!”

I always remind them: If you are sitting near a window in your office or driving in your car, those UVA rays are reaching you. You may not be burning, but the “aging” process is happening. You must have a “Broad-Spectrum” sunscreen to be protected from both.

The #2 Reason: Your Most Powerful Anti-Aging Product

Okay, now we can talk about the aesthetics. As the owner of a medical spa, I have clients come to me every day concerned about visible aging. They point to fine lines, wrinkles, and dark “sun spots” that they want to correct.

I am always gentle when I tell them this, but it’s the truth: Most of what you think of as “aging” is not aging at all. It’s sun damage.

What is Photoaging? (And How to Stop It)

Scientists have a term for it: photoaging. It’s the premature aging of your skin caused by repeated exposure to UV light.

That leathery texture? That’s photoaging.

Those deep wrinkles and loss of elasticity? That’s photoaging.

Those stubborn brown spots and uneven tone? That’s photoaging.

It’s not just a guess. Multiple studies have concluded that the sun is responsible for up to 80-90% of the visible changes to the skin that we blame on age.

Still not convinced? Let me tell you about my favorite study. It’s a famous, high-quality Australian study that was published in the Annals of Internal Medicine.

Researchers followed over 900 people for four and a half years. They split them into two groups. One group was told to use sunscreen “at their discretion” (meaning, whenever they felt like it). The other group was instructed to apply broad-spectrum sunscreen every single day.

The results were astounding. After 4.5 years, the group that used sunscreen daily showed 24 percent less skin aging than the casual-use group.

They proved, in a real-world clinical trial, that sunscreen doesn’t just prevent future aging it gives your skin the breathing room to repair itself, making it look better now. It is, hands down, the most effective anti-aging product you can buy.

The ‘Skincare Multiplier’: Sunscreen Protects Your Investment

This is the part I am most passionate about in my own practice. You are investing time and hard-earned money into your skin, whether it’s on a $150 bottle of Vitamin C serum or a series of treatments at my spa.

Sunscreen is what protects that investment.

Don’t Let the Sun Undo Your Routine

I often see clients who are frustrated. They’ll say, “Rosalie, I’m using the retinol you recommended, but my skin is still so sensitive!” or “I’m using this expensive brightening serum, but my dark spots aren’t fading!”

My first question is always: “Are you wearing and reapplying your SPF 30+?”

Nine times out of ten, that’s the missing link.

• If you use Retinoids (Retinol): These powerhouse ingredients work by speeding up cell turnover. This is fantastic, but it means the new, fresh skin they reveal is highly sensitive to the sun. Using retinol without sunscreen is like taking one step forward and two steps back. You’re causing more sensitivity and damage.
• If you use AHAs/BHAs (Acids): Glycolic, lactic, and salicylic acids are wonderful for exfoliating. But, like retinol, they make your skin more photosensitive.
• If you use Vitamin C (Brighteners): Vitamin C is an antioxidant that helps fight free radical damage from the sun. But it is not a sunscreen. If you’re using it to fade dark spots, but you’re not wearing SPF, the sun is just creating new spots and undoing all your hard work.

Sunscreen is the “lock” that seals in all the benefits of your other products.

CRITICAL: Post-Procedure Protection

This is where my voice gets firm. If you have come to Rose Medical Aesthetics, or any med spa, for a professional treatment, sun protection is no longer optional it is a mandatory part of your healing.

Treatments like laser, chemical peels, and microneedling are amazing. They work by creating a controlled, micro-injury to the skin, which signals your body to flood the area with collagen and new, healthy cells.

But this new, healing skin is incredibly fragile. It has almost no natural defense against UV radiation.

If you go in the sun unprotected after one of these procedures, you are risking:

1. Severe Hyperpigmentation: You can develop new, dark splotches that are often worse than the original issue you were trying to treat.
2. Scarring: The sun can interfere with the delicate healing process and cause permanent texture changes.
3. Ruining Your Results: You are, quite literally, throwing away the money and recovery time you just spent.

I always tell my clients: For the two weeks after a procedure, you are a vampire. You live in the shade, you wear a wide-brimmed hat, and you apply a high-SPF, mineral-based sunscreen religiously. There are no exceptions.

Expert-Led Facts: Debunking Common Sunscreen Myths

As a medical professional, I spend a lot of time “myth-busting.” The misinformation online is overwhelming. Let’s clear up the biggest myths I hear every day.

Myth 1: “I have dark skin, so I don’t need it.”

This is, by far, the most dangerous myth I encounter. As a provider, I want to be incredibly clear on this: it is absolutely false.

• The Health Risk: It is true that skin of color has more melanin, which provides some natural protection. But it’s not enough. Studies show that dark skin has a “natural” SPF of about 13.4, which is far below the AAD-recommended 30.
• The Critical Fact: While melanoma is less common in people of color, it is often diagnosed at a later, more dangerous stage. Because of this, the 5-year melanoma survival rate for Black patients is only 70%, compared to 94% for white patients. It is a deadly disparity, and sunscreen is a key tool in closing that gap.
• The Aesthetic Risk: My clients with darker skin tones are often most concerned with hyperpigmentation and melasma. The #1 trigger for both? Sun exposure. A daily, broad-spectrum sunscreen is the most important step for achieving an even, clear complexion.

Myth 2: “It’s cloudy, or I’m indoors.”

Remember our discussion about UVA rays? Up to 80% of the sun’s UV rays can penetrate clouds. And those same UVA rays are coming right through your car and office windows. If you can see, there is light. And if there is light, there is UV.

Myth 3: “My makeup has SPF, so I’m covered.”

I love a good multi-tasking product! But the SPF in your foundation is not enough.

Here’s why: To get the actual SPF number listed on the bottle, you need to apply a very thick layer we’re talking the “2-finger rule” (a strip of sunscreen down your index and middle fingers) just for your face and neck.

Are you applying that much foundation? I didn’t think so! Think of the SPF in your makeup as a nice little bonus, but never as your primary protection.

How to Make Sunscreen Your #1 Habit

The best sunscreen is the one you will actually wear. But here is my professional checklist for finding a good one.

The AAD-Approved Checklist: What to Buy

• SPF 30 or Higher: This is the non-negotiable minimum recommended by the American Academy of Dermatology. SPF 30 blocks 97% of UVB rays.
• Broad-Spectrum: This means it protects you from both UVA (aging) and UVB (burning) rays.
• Water-Resistant: This is a must if you are swimming or sweating. (Note: No sunscreen is “waterproof.” You must reapply.)

Chemical vs. Mineral (Physical): A Simple Choice

I get this question all the time. Both are great! They just work differently.

Feature	Mineral (Physical) Sunscreen	Chemical Sunscreen
How it Works	Sits on top of the skin to reflect/scatter UV rays.	Absorbs UV rays and converts them into heat.
Key Ingredients	Zinc Oxide, Titanium Dioxide	Avobenzone, Oxybenzone, Octisalate, etc.
Best For	Sensitive skin, acne-prone, post-procedure.	Daily wear, swimming (often blends easier).
Pros	Works immediately, less irritating.	Tends to be lighter, no white cast.
Cons	Can leave a “white cast” (though new formulas are amazing).	Can sting eyes, requires 15-20 min to work.

Personally, for post-procedure or very sensitive clients, I almost always recommend a Mineral sunscreen.

The Right Way to Apply (and Reapply)

• When: Apply sunscreen as the very last step of your skincare routine, right before you apply makeup.
• How Much: Use the 2-finger rule for your face and neck. For your body, you need a full “shot glass” (one ounce). Most people only apply 25-50% of what they need.
• How Often: Reapply every 2 hours if you are in direct sun, and immediately after swimming or heavy sweating.

Conclusion: The Easiest Step for the Biggest Impact

As you can tell, I’m passionate about this. In my clinic, I’ve seen what happens when skin is neglected, and I’ve seen the incredible transformations that are possible when it’s protected.

Your skincare routine can be three steps or ten, but it must include sun protection. It is the only product that:

1. Dramatically reduces your risk of skin cancer.
2. Is the most powerful anti-aging tool in your arsenal.
3. Protects your investment in every other product and procedure.

At Rose Medical Aesthetics, my philosophy is not about “fixing” you, it’s about protecting and celebrating the skin you’re in. We are here to guide you with expert-led treatments, from lasers to facials, but our partnership starts with a commitment to your skin’s health. And that commitment begins, every single morning, with sunscreen.

Make it your non-negotiable step. Your skin will thank you for decades to come.