Here's everything we learned about sunscreen from The Science of Beauty by Dr Michelle Wong.
How do I choose a sunscreen?
A sunscreen should be protective enough for the activities you’re doing. It should also be comfortable and budget-friendly, so it can be generously applied and reapplied.
For daily wear, a broad spectrum sunscreen with SPF 30 or higher is recommended. Water-resistant sunscreens are usually also more resistant to sand, rubbing, and movement, so they tend to be better suited for outdoor activities.
What’s the difference between chemical and physical sunscreen?
In practice, the main difference between chemical (organic) and physical (inorganic) sunscreens is texture. Chemical sunscreens tend to be lighter and can sometimes be greasy, while physical sunscreens are usually heavier and more drying.
Additionally, some people find specific chemical filters irritating to the skin and eyes, while physical filters often look white on darker skin (tinted sunscreens can make this less noticeable). Combination or hybrid sunscreens contain both types of filters.
Do I need to wear sunscreen if I have darker skin?
Skin colour reflects the types, amount, and distribution of melanin. Two types of melanin (eumelanin and pheomelanin) are present in all skin tones, but are more abundant in darker skin. Melanin protects against many forms of skin damage including sunburn, cancer, and some types of photoaging. Very dark skin can have in-built protection equivalent to SPF 15. However, dark skin can still burn, so sun protective measures are still recommended.
How much sunscreen should I apply?
Regardless of what SPF you use, you won’t get adequate protection if you apply it incorrectly. You should apply 1/4 teaspoon (1.25 ml) or two generous finger lengths for the face, one shot glass (35 ml) for an average adult body, with roughly 1 teaspoon (5 ml) for each of the following: face, neck, and ears; each limb; front of body; back.
When should I apply suncreen?
Before sun exposure – allow 5–10 minutes for sunscreen to dry and settle. Sunscreen should be reapplied every two hours as the sunscreen layer shifts over time and leaves gaps. Also reapply after swimming and towelling.
Do I need sunscreen indoors?
Glass blocks UVB but not all UVA, so sun protection can be important inside your car, and in sunny indoor areas near windows.
Can I apply sunscreen with other products?
Sunscreen works best when the layer is disturbed as little as possible. When layering, it goes after your other skincare products and before makeup. Sunscreen does not need to be absorbed into skin to “activate”. It should not be mixed with other products as this can create gaps in the protective layer.
Can sunscreen be bad for me?
There is no compelling evidence of long-term health harms from sunscreen, despite over 50 years of widespread use. In contrast, there is very good evidence for the need to protect against excessive sun exposure. Sunscreen is a therapeutic product in many countries, so their ingredients are some of the most closely regulated and scrutinized in skincare.
Do I need to wear sunscreen if my makeup has SPF?
SPF-rated makeup might make it seem like you can apply sunscreen and makeup in one time-saving step. Unfortunately, it’s unlikely that you’ll apply enough of a makeup product to get adequate UV protection.
A sunscreen should be protective enough for the activities you’re doing. It should also be comfortable and budget-friendly, so it can be generously applied and reapplied.
For daily wear, a broad spectrum sunscreen with SPF 30 or higher is recommended. Water-resistant sunscreens are usually also more resistant to sand, rubbing, and movement, so they tend to be better suited for outdoor activities.
What’s the difference between chemical and physical sunscreen?
In practice, the main difference between chemical (organic) and physical (inorganic) sunscreens is texture. Chemical sunscreens tend to be lighter and can sometimes be greasy, while physical sunscreens are usually heavier and more drying.
Additionally, some people find specific chemical filters irritating to the skin and eyes, while physical filters often look white on darker skin (tinted sunscreens can make this less noticeable). Combination or hybrid sunscreens contain both types of filters.
Do I need to wear sunscreen if I have darker skin?
Skin colour reflects the types, amount, and distribution of melanin. Two types of melanin (eumelanin and pheomelanin) are present in all skin tones, but are more abundant in darker skin. Melanin protects against many forms of skin damage including sunburn, cancer, and some types of photoaging. Very dark skin can have in-built protection equivalent to SPF 15. However, dark skin can still burn, so sun protective measures are still recommended.
How much sunscreen should I apply?
Regardless of what SPF you use, you won’t get adequate protection if you apply it incorrectly. You should apply 1/4 teaspoon (1.25 ml) or two generous finger lengths for the face, one shot glass (35 ml) for an average adult body, with roughly 1 teaspoon (5 ml) for each of the following: face, neck, and ears; each limb; front of body; back.
When should I apply suncreen?
Before sun exposure – allow 5–10 minutes for sunscreen to dry and settle. Sunscreen should be reapplied every two hours as the sunscreen layer shifts over time and leaves gaps. Also reapply after swimming and towelling.
Do I need sunscreen indoors?
Glass blocks UVB but not all UVA, so sun protection can be important inside your car, and in sunny indoor areas near windows.
Can I apply sunscreen with other products?
Sunscreen works best when the layer is disturbed as little as possible. When layering, it goes after your other skincare products and before makeup. Sunscreen does not need to be absorbed into skin to “activate”. It should not be mixed with other products as this can create gaps in the protective layer.
Can sunscreen be bad for me?
There is no compelling evidence of long-term health harms from sunscreen, despite over 50 years of widespread use. In contrast, there is very good evidence for the need to protect against excessive sun exposure. Sunscreen is a therapeutic product in many countries, so their ingredients are some of the most closely regulated and scrutinized in skincare.
Do I need to wear sunscreen if my makeup has SPF?
SPF-rated makeup might make it seem like you can apply sunscreen and makeup in one time-saving step. Unfortunately, it’s unlikely that you’ll apply enough of a makeup product to get adequate UV protection.
The Science of Beauty
The Science of Beauty
View BookThe Science of Beauty reveals the truth behind the bold marketing claims and viral TikTok trends, and tells you what you really need to know about the products you use every day. Dr Wong will show you how to form good habits and learn what really works. Decipher the ingredients that make up your make-up, find out the facts about botox and laser treatments, and discover whether beauty brands can ever be truly sustainable.