What You Need to Know About SPF in Your Sunscreen?

Everyone has a love-hate relationship with the sun.  The sun is an essential component for our survival. It provides a good source of vitamin D and it is the essential life-giving energy for all plants and trees. 

It is essential to remember, however, that too much sun exposure without the necessary protection can burn the skin and potentially lead to skin cancer. This is because the sun emits harmful Ultraviolet A (UVA) and Ultraviolet B (UVB) rays that damage our skin, causing it to age prematurely.

Differences between UVA and UVB

Both UVA and UVB are harmful ultraviolet radiation emitted by the sun that reach our skin, causing potential damage and premature aging if our skin is unprotected. Both UVA and UVB are not within the spectrum of visible light that we can see with our naked eyes. 

UVA and UVB rays

What you need to know about UVA:

  • Has a longer wavelength than UVB.
  • Accounts for about 95% of the UV rays that reach the earth’s surface.
  • Present even though the sun is not overhead.
  • Penetrates deep into the skin, destroying every layer of the skin, including collagen and elastin fibers.
  • Leading cause of wrinkles and some types of skin cancer.
  • Immediate tanning effect, sometimes causing a sunburn.
  • Penetrates windows.

What you need to know about UVB:

  • Largely dependent on geographic location and time of the day, with 10am to 2pm being the peak hours.
  • Makes up only about 5% of the sun’s UV rays as they are mostly absorbed by the ozone layer, but some rays still get through.
  • Wavelengths are much shorter than UVA.
  • Affects only the topmost layer of the skin.
  • Directly damages the DNA of the skin, causing most skin cancers.
  • Don’t penetrate windows.

How to protect your skin?

Sunscreen is the single most important part and also the first line of defence against UVA and UVB. It takes consistent effort to protect yourself from the sun’s rays, especially if you know you’re going to be outdoors for an extended period of time.

Choose a sunscreen that offers a broad-spectrum protection. This means that the sunscreen has the ability to shield you from UVA and UVB rays. Generally speaking, a higher sun protection factor (SPF) provides more protection. 


So, what exactly is SPF in sunscreen?

To get maximal protection from the sun, you need to opt for a broad-spectrum sunscreen – manufactured to shield you from UVA and UVB rays. It is also important to note that there is no sunscreen that blocks 100 percent of UVB rays.

The American Academy of Dermatology recommends using a sunscreen that has at least SPF30. Consumers are often misled to think that SPF100 will get twice the protection as compared to SPF50. The truth is that the extra protection that SPF100 provides is negligible. 

As a general guide, SPF15 blocks 93 percent of UVB rays, SPF30 blocks 97 percent, SPF50 blocks 98 percent, and SPF100 blocks 99 percent. When used in a proper manner as directed by the manufacturers, sunscreen between SPF30 and 50 offers sufficient protection, even for people sensitive to sunburn.

Does it mean that higher SPF means better protection?

Absolutely not. In fact, high SPF sunscreens may pose greater health risks because they require higher concentrations of sun-filtering chemicals that low SPF sunscreen. Some of these ingredients have been linked to tissue damage and causing hormonal imbalance. The most common issue is allergic skin reactions. 

In particular, try to avoid the following ingredients that are commonly found in high SPF sunscreens:

  • Oxybenzone – Cause high incidences of skin allergy.
  • Octinoxate – May cause alteration of thyroid and reproductive system. Cause moderate rates of skin allergy.
  • Homosalate – Disrupts estrogen, androgen, and progesterone.
  • Octocrylene – Relatively high rates of skin allergy.
  • Avobenzone – May cause high rates of skin allergy.

Can you reverse sun damage?

If you spent a significant amount of time under the sun when you were young, you probably are experiencing some form of skin damage and photoaging, such as hyperpigmentation and wrinkles.  

To treat signs of aging, doctors often use more than one type of treatment to address different layers of the skin damaged by the constant exposure of the sun.

Laser is a non-invasive therapy that uses light energy to repair and regenerate skin cells. Laser treatments reduce the dependence for medication, improves the outcomes of the skin condition with minimal downtime. 


Laser treatments such as Dual Yellow Laser and PicoSure Laser specifically target the dark pigments in the skin, breaking down the dark pigments caused by melanin production without causing any collateral damage to surrounding skin cells.

To improve skin texture and reduce visible wrinkles on the skin, doctors often opt for collagen dermal fillers such as Radiesse to stimulate collagen production in the skin. Profhilo, an injectable treatment is a promising treatment that can reduce visible wrinkles and tighten loose skin at the same time.

Although there are many effective aesthetic treatments that can slow down or even reverse signs of aging, doctors often advise patients to protect themselves from the sun as much as possible. 

As the saying goes, “an ounce of prevention is worth a pound of cure”. Wearing sunscreen with at least SPF50 is one of the best – and cheapest – ways to protect your skin and prevent premature aging.

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