Sunscreen Tips from a Dermatologist: What SPF Should I Use?

Ep 34: Dermatologist’s Guide to Sunscreen

Read Part 1 here

Are there effective sunscreen tips? What exactly does the SPF number mean? Does a sunscreen with a high SPF protect skin better than one with a lower SPF? 

Dr. TWL: Sunscreen tips – what exactly is SPF? It’s a measure of how much UV radiation from the sun is required to produce sunburn on skin that is protected by sunscreen. Hence, as the SPF value of the sunscreen increases, there is a proportionate increase in protection against sunburn.

Relevant to what we discussed earlier about sun avoidance behavior is the common misconception that SPF rating is related to the duration of sun exposure. For example, it is often believed that wearing an SPF 15 sunscreen allows an individual to stay in the sun 15 times longer without getting sunburnt.

SPF and amount of sun exposure

This is a very simplistic way of thinking about sunscreens and SPF factor, and it is rather inaccurate. Because, SPF is directly related to the amount of solar exposure that you’re trying to protect your skin from. While it is true that the total amount of solar exposure energy is also related to the duration of solar exposure. However, there are other factors that influence the amount of solar energy reaching your skin and causing ultraviolet induced damage. For example, the intensity of solar exposure.

In a tropical country like Singapore, the intensity of our sun exposure is year-round. This is much higher than that of other countries located in the areas of temperate climates or the other latitudes. Our general advice is to avoid sun exposure or going out from 10pm-4pm when the sun is most intense. But in Singapore, the intensity of sun exposure starts all the way from 9am until about 5 or 6pm.

Chelsea: Yeah. With the sun still shining brightly all the way till 6pm here, it makes sense that the climate and where you live will affect the way you protect your skin.

Apart from SPF, are there any other sunscreen tips, or factors that affect how well sunscreens can protect our skin? 

Dr. TWL: Another factor that would influence how an individual is protected by sunscreen is skin type. In this case we’re talking about the Fitzpatrick phototypes. Phototypes one and two are fair skin Caucasian individuals who likely absorb much more UV radiation than phototypes three, four and five which refer to skin of color under the same sort of UV conditions.


The amount of sunscreen you apply is also one of the relevant sunscreen tips. More sunscreen applied results in less solar energy absorption. Additionally, the frequency at which you re apply the sunscreen is important. We recommend every three hours for re-application. However, individuals who, for example, are in water sports, then they actually need to reapply the sunscreen even more frequently. If you sweat a lot, or participate in high-intensity physical exercises, the sweat causes the sunscreen to be washed off. If you sweat heavily or there is a lot of water exposure, even water-resistant sunscreens will become less effective.

Chelsea: Those are really good sunscreen tips, protection really does depend on how much you apply and how often.

What is the ideal SPF rating to look out for? Sunscreens can go all the way up to SPF 100, is that necessary? 

Dr. TWL: SPF is best understood as a measure of the amount of sunburn protection provided by sunscreens. It allows the consumer to compare the level of sunburn protection provided by different sunscreens. In dermatology practices, we recommend SPF 30 minimum because of practical issues surrounding reapplication. Also, the fact that we are living in a year-round tropical climate. Furthermore, if you suffer from a photosensitive disorder such as rosacea or an autoimmune disease such as lupus, you also need to be particularly mindful of the kind of sun protection you have. 

Chelsea: That’s good to know because in theory sunscreens with higher SPF should give you the best protection against harmful UV radiation. But according to the annual sunscreen report published by the environmental working group, at best, high SPF sunscreens only offer slightly better protection. These could give you a false sense of security, and make you spend more time in the sun.

Have there been any developments in terms of sun protection? What are some of the new sunscreen innovations we’re seeing now in the cosmetic and skincare industry? 

Dr. TWL: The interesting developments in cosmetic science with regards to SPF, is the inclusion of multifunctional sunscreen systems developed with nature-derived botanical compounds that have in vivo SPF. These also have skin benefits which can be used as green or natural UV filters, providing broad spectrum sunscreen protection. As a multifunctional dermocosmetic formulation, it also has additional benefits of enhancing aesthetics and skin health. 

For the application of botanical ingredients in skincare that has been widely applied in the field of dermocosmetics, or cosmeceuticals, we know that plant-derived antioxidants can provide photoprotective effects due to the presence of specific compounds in these plant ingredients. For example, phenolic chromophores, phytoestrogens, carotenoids, coumarin, proanthocyanidins, anthocyanins, catechins. All these are part of a long list of botanical ingredients that have innate photoprotective properties. 

When we incorporate these compounds into sunscreens, the SPF value increases. At least from the perspective of photostability, SPF value, and maintenance of the sunscreen protection value after radiation exposure. 

What are some examples of botanical ingredients that are effective when incorporated in ingredients in sun protection? 

Flavonoids incorporated into sunscreens can help in broad spectrum protection. Anthocyanins also have photoprotective properties. Green tea extract, in particular, is worthy of mention. It contains the epicatechin 3-gallate compounds, which are photoprotective. Also, we have resveratrol which is naturally present in over 70 plant species. Both the cis and trans forms are widely popular to be part of the antioxidant property of red wine. They also act as a chemopreventive agent, preventing development of skin cancer. Transresveratrol is actually the active ingredient that the Dr. TWL Dermaceuticals Elixir- V Serum uses.

Sunscreen tips: Elixir V Serum with Transresveratrol for photoprotective effects

The Elixir-V Total Recovery Serum with transresveratrol, a potent antioxidant, is an intensely nourishing concentrate of deep hydrating, lifting and tightening peptides for the perfect V-face look.

Skin research demonstrates that trans-resveratrol is able to prevent UV-induced skin damage and chemically induced carcinogenesis process, skin cancer formation. These molecular version of resveratrol can synergize with UV filter molecules to enhance the photoprotective properties of sunscreens. 

Have there been studies or research done on whether or not these botanicals can actually protect the skin?

In terms of clinical research that involves the actual SPF value detection of these bioactive multifunctional sunscreens, we have the following results. The addition of rutin for example into sunscreen samples, actually achieved higher antioxidant activities than just pure UVA filters alone. The in vivo SPF of sunscreens with rutin found to improve the in vivo SPF levels up to about 70% even in a concentration that was generally regarded as quite low for a cosmetic active ingredient. 

So, the flavonoids in this case seem to have an active mechanism of action that is synergistic on an antioxidant level but also we can postulate that these may interfere with the lipid oxidation pathways as well. Furthermore, the use of antioxidants from natural sources extend to use of caffeine, ferulic acid, gelatin-based rutin-loaded nanoparticles. Importantly, research to date has demonstrated that these samples that have included botanical dermocosmetics that have additional SPF factor, have no side effects such as skin irritation, dermal sensitivity and photoirritation, compared with placebos. 

Chelsea: Wow that’s really interesting! It definitely combines the recent trend of natural skincare with evidence-based plant compounds that really live up to its claims!

Photoprotective properties of botanical ingredients

The use of compounds isolated from natural extracts, can be positively impact SPF values in sunscreen formulations. It’s very important that in our design of these sunscreen formulas that we include these innovative formulations. This is going to increase the photoprotective properties of the sunscreen as well as photostability. This means that the inherent sun protection value will increase on top of the ability of these antioxidants botanical ingredients to intervene separately in the skin cancer formation pathways.

The SunProtector is formulated with physical blockers like titanium dioxide and zinc oxide that effectively blocks UV radiation. Portulaca Oleracea (Purslane) and Oligopeptides included are potent antioxidants which actively fight free radicals generated by UV exposure as well as airborne pollutants – for comprehensive protection.

Cosmeceuticals for skincare

The importance of dermocosmetics for skincare is increasingly recognized in its role in adjunct treatment of dermatological conditions like rosacea, eczema. In the case of photoprotection it is key not just for the prevention of photoaging for cosmetic or aesthetic concern, but also as a chemopreventive intervention. As we see that these chemical isolates from botanical ingredients play a key role in the skin carcinogenesis pathway.

Chelsea: That’s consistent with reports showing that consumer focus has shifted from the basic idea of skin beauty towards a wider concept of not just skin appearance, but also skin health. Well that’s it for today’s episode on skincare tips. We’ve covered important factors in terms of sun protection, including what SPF ratings really mean, chemical and physical sunscreens, and what goes into an ideal sunscreen. We’ve also talked about new innovations in the realm of sun protection, and other methods of sun protection as sunscreen is just one vital part of a strategy to protect your skin. We hope that you guys have taken away a few sunscreen tips!

Thank you guys for joining us for our sunscreen tips podcast, you can follow Dr. Teo on her Instagram for the latest podcast updates @drteowanlin and also visit us on our website at of where you can find the full podcast transcript. 

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