Your Guide to SPF

By Gianne Rayandayan
Clinical Herbalist


Your skin is one of your most important bodily defenses so we want to help you keep it in top shape! An important part of sun protection is knowing how to select the right SPF product for your lifestyle and goals. At remedy, we prioritize clean skincare and our sunscreen selection is no exception! In this blog we break down the science behind SPF and UV protection, and the pros and cons of different types of sunscreen. 

What SPF Means

Sun Protection Factor (SPF) is the measure of how much ultraviolet (UV) radiation penetrates the sunscreen. The higher the SPF, the less radiation that passes through: An SPF of 15-plus filters out about 93% of rays, SPF 30-plus filters out 97%, SPF 50-plus, 98%; and SPF 100-plus, 99%. 

The SPF number indicates how long it would take UV rays to redden the skin if the product were used exactly as directed versus if no sunscreen was used. Typically we recommend an SPF of 30– past this, the difference in sun protection is very small. Therefore, it is way more important to apply frequently than it is to solely rely on the highest possible SPF.

The Two Categories of Sunscreen

The two most common types of sunscreens are chemical and mineral (also known as natural or physical sunscreen). Their mechanisms of action are very different. Chemical sunscreens work by absorbing and transforming UV rays into heat. Mineral sunscreens sit on top of your skin and block all forms of light, including UV rays. 

While chemical sunscreen is easier to apply and does not leave a white sheen, it is not without downsides. For one thing, it does not offer as much protection from other forms of light compared to mineral sunscreen. Infrared and visible light (e.g. blue light) play a role in conditions like hyperpigmentation; unlike mineral sunscreen, chemical blocks neither of these. If you spend a lot of time in front of a computer (most of us!) this is a big reason to make sure your face sunscreen is a mineral sunscreen.

Chemical sunscreen is also shown to be damaging to marine ecosystems and potentially carcinogenic. 

Of the 16 active sunscreen ingredients measured for efficacy AND safety, only two satisfy both criteria-- titanium dioxide and zinc oxide, which are the mineral sunscreens. If your aim is to find the safest sunscreen for your family while minimizing ecological damage, mineral sunscreen is the best option by far. We suggest reserving chemical sunscreens as a last resort whenever possible! 

How to Maximize SPF 

Sunscreen is such an important daily staple for San Diegans, so we always aim to bring in brands that are mineral based, sustainably made, and if possible, local! Below are a few tips on how to maximize your sunscreen’s SPF: 

Tip 1: Wear sunscreen daily - UVA rays penetrate windows and cloud cover. Even if you are rarely under direct sunlight, experts recommend wearing sunscreen every single day. This is especially important for preventing premature aging. Salt & Stone’s SPF 40 Sheer Daily Sunscreen is a great option for daily face protection because of how lightweight and non-greasy it is– ideal for applying under makeup! It also comes in an aluminum tube which is 100% recyclable. 

Babo Botanicals is a great daily option for babies’ sensitive skin. Their Clear Zinc Unscented Sunscreen SPF 30 gets a perfect EWG rating of 1, which is huge considering less than 18 percent of products tested receive a perfect score.

If your skin runs dry, their Salt & Stone’s SPF 30 face and body lotion incorporates hyaluronic acid for daily moisturization. Since UV damage is essentially a form of free radical damage, lean on antioxidants whenever possible. Salt & Stone SPF 30 incorporates herbs like calendula, green tea, and ashwagandha, which are known for their skin-healing and antioxidant properties. 

Tip 2: Actually wait the recommended 15 minutes - Most folks skip this step , but it is in fact very important! Mineral sunscreen needs time to dry and adhere to your skin’s top layer before it starts working. Salt & Stone’s SPF 50 tinted mineral sunscreen stick has a super convenient application perfect for folks pressed for time. 

Tip 3: Reapply often!- Like we’ve mentioned, sunscreen protection plateaus significantly once you get past SPF 30. Reapplying every 2 hours or 80 minutes if swimming is the best way to make sure you are protected throughout the day. Kids who are outdoors will benefit from Babo Botanicals’ gentle Baby Skin formula.

Tip 4: Clothing as a physical blocker - Apart from sunscreen, the best way to avoid UV damage is to simply minimize sun exposure however you can. Wear hats, sunglasses, and long sleeves between the hours of 10am and 2pm, especially if you live in a part of the world with intense sunny weather.


Lastly, It would behoove anyone looking to protect their skin to also supplement with antioxidants like NAC, Resveratrol, or Coq10. Topical vitamin C powder can help minimize existing dark spots and pure aloe gelly is a tried and true sunburn healer! If you want more help with recommendations for UV protection and post-sunburn repair, stop by our pharmacy or give us a call!