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SPF 101: Everything You Need to Know About Sunscreen

Ah, sunscreen. The unique smell as a kid that told you something fun was going to happen. Now, it's a daily step in our skin care routines - if it's not, this is your sign! This blog will tell you all about SPF, how much is enough, and which sunscreen might be right for you.

SPF Explained

SPF stands for Sun Protection Factor. This is a measurement that tells you how well the sunscreen will protect you from UVB rays. It indicates about how long it will take for your skin to develop a sunburn versus the the time it would take without using sunscreen. For example, with SPF 30, it would take about 30 times longer to develop a sunburn when using sunscreen correctly than if you didn't use any at all. Most sunscreens protect only against UVB rays, but if you purchase a "broad spectrum" SPF, this means it will protect your skin from both UVB rays and UVA rays. What's the difference? While they both contribute to sunburn and skin cancers, they are each mainly responsible for:

  • UVB Rays, UVB(urning): These are the rays that cause sunburn and play a key role in developing skin cancer. Most sunscreens protect against these rays.

  • UVA Rays, UVA(ging): These rays cause skin damage that leads to tanning, wrinkles, fine lines and age spots. Having a sunscreen that proclaims "broad spectrum" can protect you against these rays as well as UVB rays.

High SPF vs Low SPF

There are so many SPF numbers, how do you know which one to go with? To put the SPF ratio into perspective: an SPF 15 allows for about 7% of the UVB rays to hit your skin, 3% for an SPF 30, and 2% for an SPF 50. In other words, SPF 15 will protect you from 93% of these rays, SPF 30 will protect you from 97% of UVB rays, and SPF 50 will protect you from 98% of the rays. Experts suggest staying in between SPF 30 and 50, which grants sufficient protection without getting a false sense of security. Anything over SPF 50 may offer marginally better protection, but no sunscreen can protect you against 100% of the sun's rays.

Two Types of Sunscreen

The two types of sunscreen are physical (mineral) and chemical. The main differences between the two are the active ingredients in each and the way in which they block the sun's rays. There are pros and cons to both, but SPF is a non-negotiable, and the info below will help you in figuring out which kind works better for your skin.

Mineral sunscreen sits on top of your skin and acts as a shield. The active ingredients in physical sunscreens often include zinc oxide and/or titanium dioxide. These sunscreens deliver broad spectrum protection since the ingredients reflect the rays off your skin. Mineral sunscreens are a great choice to ward off UVA damage including wrinkles, age spots, and photoaging - which is another word for sun damage. Zinc oxide sunscreens are often recommended for those with acne-prone skin or children. The only really downside of physical sunscreens are that they can be chalky, hard to spread, and can often even leave a white film since it doesn't absorb in the skin. They can also be less water resistant than chemical sunscreens, so apply diligently.

Pro tip: opt in for a tinted zinc oxide to avoid the white film.

Chemical sunscreens do not sit on top of your skin like mineral sunscreens do, these ingredients absorb into your skin and act more like a sponge for the UV rays - absorbing them before your skin has a chance to. Some common ingredients in chemical sunscreens include: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate. There is much debate on the safety of some of these chemicals. One study done in 2020 suggests that 6/12 of ingredients currently under study of the FDA enter the bloodstream after just one application, and can stay there for 3 weeks. The level these chemicals were found were said to pass the threshold where the FDA considered waiving additional safety trials. Another downside to chemical sunscreens is that people with sensitive or acne-prone skin may experience inflammation or redness. Some ingredients could make skin conditions like rosacea and melasma worse.

Is Sunscreen Bad for the Environment?

Some of the active ingredients in sunscreen like xybenzone, octocrylene, and octinoxate have been found in correlation with dying coral reefs. Our coral reefs absorb nanoparticals, or very tiny partials, that can cause them to die. Look out for sunscreens that have no nanoparticals if you're planning on swimming in the ocean. Eco-friendly sunscreens may not be a requirement for you, but we need coral reefs in order to survive. Try to purchase mineral sunscreens that explicitly state no nanoparticals, and leave the spray bottles at home. The Ocean thanks you!

The Best Sunscreen is the one You Want to Wear Everyday.

Here are our top picks:

ISDIN Eryfotona Actinica

Eryfotona Actinica is a fast-absorbing, ultralight emulsion providing an all-mineral broad spectrum sun protection.

Its innovative formula contains DNA Repairsomes®, naturally occurring enzymes which are clinically proven to repair existing sun damage.

Active Ingredients:

Zinc oxide: A 100% mineral sunscreen which effectively blocks the sun’s harmful UVA and UVB rays.

DNA Repairsomes® Photolyase: is a repair enzyme, derived from plankton, which has been shown to help repair damage caused by the sun.

Vitamin E: An antioxidant which helps to boost skin’s natural defenses, protect against environmental damage and fight the early signs of skin aging.

ISDIN Eryfotona Ageless

Protect, repair, and correct with Eryfotona Ageless, an ultralight tinted sunscreen with zinc oxide which helps fight the signs of photoaging. Its innovative formula uses 100% mineral SPF 50 sunscreen, an innovative blend of peptides, antioxidants, and DNA Repairsomes® to repair existing sun damage and reduce the appearance of fine lines and wrinkles.

Active Ingredients:

Zinc oxide

DNA Repairsomes®

Peptide Q10: Helps to keep skin cells healthy and fights the early signs of photoaging.

Peptide complex: Supports collagen and improves elasticity to reduce the appearance of fine lines and wrinkles.

Vitamin E

ISDIN Mineral Brush

Isdinceutics Mineral Brush provides on-the-go protection against the visible signs of photoaging: the ideal complement to your daily sun protection and skincare routine.

A silky, smooth, fine powder containing titanium dioxide, zinc oxide, mica and iron oxides provides protection against free radical pollution damage, blue light and infrared radiation (IR). Take it with you for photoaging defense and matte, natural coverage wherever you go!

Revision SkinCare Intelleshade

A 5-in-1 daily anti-aging tinted moisturizer with broad-spectrum SPF 45 that is formulated to correct, protect, conceal, brighten and hydrate skin. Prevents visible signs of aging and enhances skin’s natural moisture barrier, improves the appearance of fine lines and wrinkles and brightens and evens skin tone while reducing the appearance of redness. Also protects skin from UVA/UVB radiation. The sheer mineral tint conceals and restores skin’s youthful appearance.

Active Ingredients:

Blend of Three Peptides: Improves the appearance of fine lines and wrinkles. THD Ascorbate: Vitamin C Blend of White Birch Extract, Yeast Extract, Plankton Extract and Coenzyme Q10: Enhance the skin and encourage overall skin health. Octinoxate & Octisalate: Sunscreen

Zinc Oxide & Titanium Dioxide: Provide UVA & UVB protection.

You can purchase all of these products through our clinic, The Lotus Aesthetics and Wellness.

To book with our amazing team, click here! Or call 210-774-2850.

Ask the expert: Does a high SPF protect my skin better? The Skin Cancer Foundation. (2022, March 26). Retrieved April 19, 2022, from

Timmons, J. (2022, February 3). Should you use physical or chemical sunscreen? Healthline. Retrieved April 19, 2022, from

Yowell, H. (2020, July 15). Sunscreen 101: Everything you need to know about SPF. Heyday. Retrieved April 19, 2022, from


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