Jeffrey C. Dawes MD, FRCSC

Using Sunscreen

What you need to know about sunscreen protection

The use of topical sunscreen protection plays an important role in helping to shield your skin from the photodamage that leads to premature aging of the skin and serious diseases, such as skin cancer. As well, many medications and topical products can increase skin’s photosensitivity, heightening its vulnerability and the need for topical protection.

However, not all sunscreens are created equal—they vary in their effectiveness against the photodamage caused by sun exposure. Despite claims of adequate UV protection, some products rely on less-effective chemical filters that can break down in light, rather than more-effective mineral (physical barrier) ingredients—which prevent damaging UV rays from reaching the skin.

For example, even though a ‘broad-spectrum, SPF of 100’ sunscreen may help provide adequate protection from a UVB sunburn, it could also be ineffective against UVA rays after as little as 30 minutes of sun exposure—allowing undetected photodamage to your skin.

UVA and UVB: What does that really mean?

Both are ultraviolet sunrays that damage your skin. UVB rays cause sunburns, the most visible and immediate symptom of sun over-exposure. UVA rays are called the ‘aging rays’—they do harm without causing visible sunburns, penetrate the skin more deeply, are more abundant than UVB, and can pass through glass. Despite their differences, both UVA and UVB rays can cause skin cancer.

A mineral-based sunscreen offers true UVA/UVB protection

Many sunscreens offer an SPF rating, and claim ‘broad-spectrum UVA/UVB’ protection. However, an SPF applies only to the UVB (burning) rays. Chemical filters, such as Avobenzone, can break down when exposed to light, allowing exposure to the UVA spectrum. Mineral (physical) barriers, such as zinc oxide, do not break down, and protect across the full UVA/UVB spectrum when properly applied.

For the most effective sun protection, look for mineral-based sunscreens that contain zinc oxide and/or titanium dioxide in concentrations greater than five percent. As well as preventing additional photodamage, this type of sunscreen gives the skin a reprieve from both types of radiation, allowing it to partially repair itself from previous damage.

Diligent use of sunscreen helps protect your skin

Some tips for using sunscreen protection:

  • Apply mineral-based sunscreen to your face, top of ears, neck and upper chest every morning, regardless of weather and time of year. Wear it beneath makeup.
  • For adequate coverage, do not rely solely on makeup or foundations containing SPF.
  • On hot days, reapply mineral-based sunscreen every three-to-four hours.
  • Mineral-based sunscreens tend to be more expensive—use them on areas more frequently exposed, such as the face, ears, neck, shoulders and tops of arms. Use less-expensive chemical-based sunscreens on other areas, if needed, to save money.

We offer exceptional sunscreen products

We offer a high-end skincare product line, including excellent mineral-based sunscreens in lightweight and non-greasy formulas. If you have additional questions or concerns about sun protection, please call our office at (403) 571-3141 to speak with our skincare nurse.


Do mineral-based (physical) sunscreens prevent the skin from absorbing Vitamin D?

Recent research suggests this possibility; however, much is still unknown about how the skin and body absorb Vitamin D from the sun. Speak to your doctor about the possibility of taking Vitamin D supplements while protecting your skin from photodamage through the use of sunscreen products.

Can medications increase my chances of getting a sunburn?

Yes. But not just a sunburn—they can also increase your risk of undetected photodamage from UVA (aging) rays. Many commonly-used medications and topical products can reduce your skin’s already-limited ability to protect itself from the sun. Using a mineral-based sunscreen helps to protect your skin from UVA/UVB exposure, especially when photosensitivity exists.

What medications can cause photosensitivity?

There are over 400 medications and topical products that can cause or increase photosensitivity, including retinol, NSAIDS, antibiotics, birth-control pills, anti-depressants, cortico-steriods and hormonal replacements. Please call our office for a complete list of these medications and products, or speak with your family doctor.