Is Your Over-the-Counter Sunscreen Helping You or Hurting You?
Before we get into the details, let’s consider why people choose to wear sunscreen. Here are the top 3 reasons:
- To prevent sunburn
- To prevent skin cancer
- To prevent premature aging and sun spots (aka liver spots, old age spots, hyperpigmentation)
So, with these reasons in mind, the question is, how do you choose a sunscreen with the hundreds and even thousands of choices on the market? Most people choose based upon the application style they like (sprays, lotions, oils, powders) and the level of SPF protection. Unfortunately, this decision should be based upon much more important factors such as underlying skin conditions, skin type (color), and type of sunscreen.
Understanding the Sun’s Rays – The Basics
The sun emits two types of radiation, UVA rays and UVB rays. UVB rays are typically the cause of sunburn, whereas UVA rays penetrate deeper into the skin causing more permanent damage to your skin cells, collagen and elastin.
Two Types of Sunscreens
Chemical sunscreen is the most common form found in retail stores. When it is exposed to the sun’s rays, a chemical reaction occurs. During this reaction, the sun’s rays are actually absorbed into the skin, transformed into heat and then the heat is eventually released from the skin. Chemical UV filters often only protect against UVA or UVB rays but rarely both. So, what are these chemicals that we are using to “protect” our skin?
- Avobenzone quickly degrades in sunlight so reapplication often is critical.
- Octinoxate is also an endocrine disruptor that can affect thyroid function
- Octisalate is a penetration enhancer which increases the amount of ingredients that can pass into your skin.
- Oxybenzone is a photosensitizer which means it increases the body’s production of free radicals. It is also suspected to be a hormone disrupter that may affect the production of estrogen.
- Octocrylene also increases the production of free radicals.
In addition to the intentional chemical ingredients above, an independent lab reported a known carcinogen called benzene (a solvent) in 78 sunscreens and after sun products made by 69 different companies.
So, if you choose to use a chemical sunscreen, be sure to read the label to know which chemical ingredients you’re putting on your skin and what that might mean for your health. Also, don’t forget to apply chemical sunscreens 20 minutes before sun exposure and don’t get it near your eyes since burning and irritation may occur.
Physical Block (Mineral Sunscreen)
Two naturally occurring minerals, Titanium Dioxide and Zinc Oxide, are FDA approved for sun protection. Titanium Dioxide is known for having the white appearance. Zinc Oxide is the only FDA approved ingredient that protects the skin from both UVA and UVB rays. You will often find both ingredients in one product. The main difference between mineral (physical) block sunscreens and chemical are how they work. Instead of absorbing the sun’s rays into your skin like chemical sunscreen does, physical SPF reflects the rays off of and away from your skin. That means, heat is also not absorbed into the skin making this a much better choice for people with melasma or rosacea. We always recommend the use of physical block sunscreen over chemical. They can be a little harder to find on the retail shelf so you may want to buy from your local dermatologist or Medical Spa.
Understanding SPF Ratings
Reapplication of sunscreen is the only way to keep your skin protected so understanding the best rating for your particular skin type and how often you need to reapply is very important. The chart below is a great tool to help you know what’s best for you.
Recommendations for Melasma and Rosacea
Remember, chemical sunscreens cause heat to build up in the skin as it absorbs the sun rays. This additional heat often causes more rosacea related redness and increased melasma related hyperpigmentation (brown patches and spots). If you have either of these skin conditions, we highly recommend you do not use chemical sunscreen, especially on your face.