Why choose a sunscreen stick or balm?
Sunscreens in a waxy and solid base are portable, easy to apply, and can offer good water-resistance. They’re a great way to protect the lips and the skin around the eyes, and are small enough to fit in your pocket.
They can keep sunscreen from running into your eyes!
Applied around your eyes stick or balm sunscreens can help prevent other sunscreens from migrating into your eyes and causing stinging or blurring.
Sticks or balms with higher melting points tend to be better at this task. Look for ones that are harder and don’t melt when you hold your finger to it.
No more stinging, squinting eyes!
Do I Need To Protect My Lips?
Yes! Just like the rest of your skin, your lips are susceptible to UV exposure. The lower lip especially is among the most exposed areas to UV on the face 1.
Lips lack some of the natural photoprotection that the rest of the skin has. There’s less melanin, which acts as a natural sunscreen by converting UV energy into heat 2. Also sebaceous glands are absent. The sebum produced by these glands contain photoprotective antioxidants like Vitamin E 3,4. The skin of your lips is also about a third thinner than the rest of your skin.
Like the rest of your skin, UV exposure increases your risk of developing skin cancer. Lip cancers represent 0.6% of skin cancer cases, and are most common in men over 50 5. Thankfully, they have a very high cure rate (90-100%) 6, 7. Oral melanoma is much more rare and vastly more lethal, and is also linked to UV exposure 8. If you do find new spots on your lips or inside your mouth – please get it checked!
Interestingly, one study found that minimum amount of UV energy to cause marked redness was 25% lower on the lips compared to back skin 9. The amount of skin reddening is used to determine SPF. What this could imply is that our lips have better protection against UV, from something other than skin thickness, antioxidants, and melanin content. However, only the upper lip was tested, the comparison of protected and unprotected skin was performed on the upper and lower lip, and the analysis was performed by different labs.
How much of the stick or balm do I need to apply?
SPF and UVA protection are tested at a global standard of 2 mg/cm².
This information isn’t too useful for the lips, their size varies greatly, and you can’t really measure the amount of product easily.
One would assume that sunscreen sticks are designed to supply the required 2 mg/cm², but unfortunately that is not the case.
A group of researchers studied the amount of sunscreen applied when using a stick or balm. They found that the median amount applied was only half of the required density 11. 3 of the 28 participants applied close to the required amount, with 1 participant applying a whopping 2.5 mg/cm².
Based on this, if you want the amount of photoprotection labelled you’ll have to apply the sunscreen twice.
This applies to all types of sunscreen sticks or balms. How stiff or soft the sunscreen was didn’t affect how much was applied. Despite this, researchers recommended choosing a stiffer stick or balm. They suggest that softer and oilier products feel like they deposit more sunscreen, which isn’t true!
How often should I be re-applying?
Unfortunately there isn’t a convenient recommendation that’s based on a lot of strong scientific evidence, however at a minimum you should tryt to reapply the sunscreen after 15 minutes to 2 hours of cumulative UV exposure 12.
Since sunscreen sticks or balms are easily wiped off, you should reapply after eating, drinking, wiping your mouth and anything else that may remove the product (like kissing!).
How to choose a sunscreen stick or balm
Look for a product with an SPF of 30 or greater. You want a product with full coverage of the UV spectrum, UVA and UVB. Most sunscreen stick or balms available in the US and Canada only provide strong UVB protection, this is especially true of products that are SPF 15.
In the US and Canada, look for products that have the “broad spectrum” labelling. While it’s only a relative assessment of the UVA protection, it’s the only information we have regarding the UVA protection. Canadians have access to products containing better UVA sunscreens like Tinosorb S and M, as well as Mexoryl SX and XL. La Roche Posay, Avene, and Vichy have these sunscreen chemicals in some of their formulations.
Other countries have different standards for UVA protection labelling. In the UK and Europe look for a high UVAPF, PPD, or the UVA circle logo. In Japan look for products with a PA rating of +++ or higher.
In terms of texture of the product, it doesn’t make a significant difference in how much is applied per swipe. However, products with a higher melting point (they’ll feel stiffer and don’t melt as easily when you touch them), may last longer on the skin as they’re less easily wiped off.
I personally switch between Bioderma’s Photerpès SPF 50+ with UVAPF 38, Avene’s Haute Protection SPF 30, and La Roche Posay’s Anthelios Targeted Protection Stick SPF 60.
Can you provide an overview of the study?
The two products used in the study were: Labello’s UV-Alpin SPF 30 Sun-Block and Garnier’s Delial Sun Stick SPF 16 (both discontinued).
The Labello product has a higher melting point than the Delial product, it feels firmer and less oily.
The study was performed in two parts:
The first experiment was performed in the laboratory. 25 students and 5 professors were asked to apply the sunscreen in front of a mirror, without instruction about how application relates to photoprotection. After the sunscreen was applied, the stick was weighed to see how much of the product was used. The mass of product used was divided by the surface area of their lips to calculate the density. The subjects’ lip area was calculated by having them kiss a piece of paper while wearing a colored lipstick. Each subject was asked to apply the sunscreen 10 times.
The second experiment was performed during a 6 day skiing trip with 18 students. For 3 days they applied one stick sunscreen, and for the remainder of the trip they applied the other stick sunscreen. The amount of times the sunscreen was applied was recorded. The difference in mass of the sunscreen sticks was divided by 3 (for each day it was applied) to get the average mass used per application. The average mass used per application was then divided by the surface area of their lips (again by having them kiss a piece of paper wearing lipstick).
In the lab, the median density of application was 0.98 mg/cm² for the Labello product and 0.86 mg/cm² for the Delial product. There wasn’t a statistically significant difference of density between the two products, so it seems the hardness of a product doesn’t make a large difference. Other factors like age, sex, skin type, or using lipstick didn’t affect the density of application either.
On the skiing trip, the median density of application was 1.58 mg/cm² for the Labello product and 1.76 mg/cm² for the Delial product. Participants applied the softer Delial product more frequently, but there still wasn’t a statistically significant difference of applied density between the two products. It’s important to note that the temperature was between -6C and 4C. The sunscreen sticks get harder when cold, which could make them transfer less product onto the lips per application. As well the colder, windy environment may have prompted participants to apply the product more frequently – not so much for photoprotection, but for protection from moisture loss.