EXPERT ADVICE

All of Your Summer Skincare Questions, Answered by a Dermatologist

Dr. Courtney Rubin shares her advice on SPF, sweat-induced acne, retinol, bug bites, and more.


two women wearing hats and bikinis lie on the beach
Photo by SSPL/Getty Images

You already know you need to wear SPF every single day. But you might be wondering, What’s the difference between chemical and mineral sunscreen? Do I really need a lip balm with SPF in it? If I’m getting sweaty outdoors, how do I protect myself without triggering a breakout? To tackle your most pressing summer skincare questions—from how to deal with itchy bug bites to whether you can apply retinol the night before a day at the beach—we reached out to Dr. Courtney Rubin, a board-certified dermatologist and co-founder of the new skincare line Fig. 1 for help. Here, Rubin, who teaches at Harvard Medical School and works at the Brigham and Women’s Hospital Department of Dermatology, shares her expert knowledge on taking good care of yourself during the sunniest part of the year.

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In terms of effectiveness, is there a difference between mineral sunscreen and chemical sunscreen?

Mineral (also called physical) sunscreens feature sunscreen filters of zinc oxide and/or titanium dioxide, while chemical sunscreens feature sunscreen filters made of organic molecules like avobenzone, oxybenzone, octinoxate, octocrylene and others. In terms of effectiveness, both chemical and mineral sunscreens can work equally effectively to block ultraviolet rays. The way to measure effectiveness is the SPF Factor. An SPF 30 mineral sunscreen will give you the same protection as an SPF 30 chemical sunscreen.

Traditionally, the thinking has been that mineral sunscreens reflect UV light, while chemical sunscreens work by absorbing the sun’s rays and converting them to (a very small amount of) heat. However, one of my favorite chemists and science educators, Dr. Michelle Wong, has spent a lot of time diving into data that actually shows both chemical and mineral sunscreens work by the same mechanism—absorbing the sun’s rays and converting them to a small amount of heat.

Why would you choose one over the other?

Chemical sunscreens are more “cosmetically elegant,” meaning that they are easier to rub into the skin without leaving behind white discoloration. Chemical sunscreens are often preferred by those who dislike the goop-y feeling of traditional sunscreen and are looking for something that blends into the skin easily and feels weightless. However, chemical sunscreens are more likely to cause irritation compared to mineral sunscreens. For those with sensitive skin, I recommend mineral sunscreens. Remember, there is no one “best” sunscreen—the best sunscreen is the one you will use!

Are there any particular sunscreen brands you recommend? What are some ingredients to look out for?

A few of my personal favorite sunscreen brands are Aveeno, CeraVe, Supergoop, EltaMD, Colorescience, and SkinCeuticals. Use a form of sunscreen that you love. For me, that’s a tinted sunscreen, because the iron oxide pigments in tinted sunscreen formulas block visible light, which we now know is involved in the development of hyperpigmentation like melasma. When I put on tinted sunscreen, I know I’m not only getting protection from UV light, but also an additional layer of protection from visible light!

I recommend that all of my patients reach for sunscreen that is at least SPF 30, and says “broad spectrum,” which means that it works against both UVA and UVB rays. Ingredients to look out for include zinc oxide and titanium dioxide, which are mineral sunscreen filters. Chemical sunscreen filters include: avobenzone, homosalate, octisalate, octocrylene. When combined, they work synergistically to fend off UVA/UVB damage.

If you do end up getting sunburned, what’s the best way to soothe it in the short term? Is there any way to prevent long-term damage once you’ve already been burned?

If you’ve already been burned, unfortunately the damage to the skin has already been done. From there, the best thing to do is focus on soothing and calming burned skin and helping it heal faster. First, get out of the sun and seek shade. A cold shower or cold compresses can soothe burned skin. Avoid scrubbing or using anything mechanically abrasive over the burned area. If the skin is painful, acetaminophen or ibuprofen can help reduce discomfort. Drink lots of water—you lose moisture faster when the skin is damaged by a burn—and don’t pop or remove blisters, as that skin will act as a biological “dressing” or bandage as the skin below heals.

What products or dermatological procedures (i.e. lasers) do you recommend to help reduce hyperpigmentation due to sun damage?

Sun exposure causes the skin to develop dark spots, also known as hyperpigmentation, over time. The best way to prevent (and also treat) hyperpigmentation is with diligent sun protection: regular use and re-application of SPF, use of sun protective clothing, and sun avoidance. Additionally, there are topical skincare ingredients that can help even skin tone and brighten. My favorites are niacinamide, vitamin C, retinol, tranexamic acid, arbutin, soy, licorice root, and kojic acid. For my patients who are very prone to developing hyperpigmentation from sun exposure, I often recommend an oral supplement called polypodium leucotomos—a natural, plant-derived extract that comes from a fern, which uses the compound to protect its delicate leaves from the sun. Research shows that polypodium leucotomos can help boost the skin’s ability to protect itself from the sun’s rays. While it isn’t a replacement for SPF and safe sun practices, it can be a helpful addition.

From a procedural standpoint, lasers and light-based treatments like Fraxel, Clear and Brilliant, and Intense Pulsed Light (IPL) can help to even skin tone and reduce hyperpigmentation. Chemical peels can also be used to even out skin tone and reduce hyperpigmentation.

How often should you get moles and freckles checked by a dermatologist? Let’s say you’ve been skimping on doctor’s visits for the past two years because of the pandemic… What sorts of irregularities warrant an immediate appointment?

There is no one right answer for how often to get moles and freckles checked. Those who have a strong family history of skin cancer, or who have had a personal history of skin cancers or atypical moles, should be getting their skin checked on a more regular basis. Some of my patients who have had many skin cancers or more serious skin cancers in the past see me every 3-4 months, while others come in every 1-2 years for skin examinations.

If you notice anything on your skin that is changing over time, whether that means growing in size, changing in color or becoming itchy or painful or starting to bleed, that usually warrants an immediate appointment.

Are there any products or ingredients that are effective when it comes to oily skin that gets even oiler in warm weather?

My skin loves to go from dewy to greasy in the summer, so I completely understand wanting to find products to control oil. Here’s how I modify my skincare routine in the summertime to deal with oily skin: In the mornings, I love using products with niacinamide, since this B vitamin brightens and evens skin tone, while also reducing excess oil production. One of my favorites is the Fig. 1 N4 Niacinamide Nourishing Treatment, which contains 4 percent niacinamide along with vitamin B5 and post-biotic bacterial ferments that support a healthy and diverse skin microbiome. After that, I usually use a lightweight moisturizer, followed by sunscreen. I carry a mineral powder sunscreen in my purse for re-application during the day (the Colorescience brush-on sunscreen is great for this), as this allows me to maintain my SPF while also absorbing excess oil.

At night, I use products with retinol, a form of vitamin A. Retinol is great because it reduces excess oil production and clears out clogged pores. Not only is it helpful for those with oily or congested skin, it’s also appropriate for those with acne, since every acne bump starts off as a clogged pore. My favorite moisturizer with retinol is the Fig. 1 Retinol Renewal Cream. It contains 0.15 percent encapsulated retinol to drive results without causing irritation.

If you’re playing a lot of sweaty outdoor sports, what’s the best way to take care of your skin so that you’re not a) getting burned and b) dealing with acne that might result from sweaty workout clothes or pore-clogging sunscreen?

If you know you are going to be outside for an extended period of time, apply sunscreen before you leave the house and at least every two hours (every water break, do a quick re-application with spray or lotion). I also recommend wearing sun protective clothing while you are outside (I love hats and visors).

The best defense against acne caused by sweat and sunscreen is to remove sweaty gym clothes and wash away the sweat and sunscreen as soon you finish your workout. Tight clothing traps dirt, oil, sweat, and dead skin cells against the skin, which can lead to clogged pores and acne. I find double-cleansing to be especially effective here, as the initial oil cleanse emulsifies and removes pore-clogging grime (sunscreen and sweaty makeup), and the second foaming cleanse ensures that no residue is left behind. I like to use an anti-bacterial body wash that contains benzoyl peroxide to help reduce acne-causing bacteria on the skin. Additionally, some people may notice an improvement in body acne if they transition to looser-fitting workout clothing that doesn’t sit so close to the skin. And always wash workout clothing between workouts.

What are the best ways to protect your skin from the drying effects of chlorine and salt water?

Chlorine and salts can be very harsh and drying to the skin. Before going swimming, I like to apply a generous layer of sunscreen that contains moisturizing and hydrating ingredients that reinforce the skin barrier and prevent dry-out, like hyaluronic acid, glycerin, squalane or ceramides. Using a sunscreen with skin-nourishing ingredients helps to protect my skin both from the sun’s rays and from the drying effects of salts and chlorine. After I finish swimming, I try to shower as soon as possible to get the chlorine and salt off of my skin, then follow up by applying a thick layer of hydrating moisturizer to my damp skin when I get out of the shower to replenish moisture.

Do you really need lip balm with SPF?

Yes! One thing that people may not realize is that the lips are an extremely common location to develop non-melanoma skin cancer, because they are constantly exposed to the sun. I recommend using a broad-spectrum lip product with at least SPF 30, and reapplying frequently as SPF on the lips tends not to last very long; we are frequently eating, drinking, and licking our lips.

How do you feel about mineral powders or face sprays with SPF in them? Are they effective enough to use on their own?

I personally am not a huge fan of SPF sprays, mostly because people tend to under-apply sunscreens, which leads to uneven protection. Additionally, anytime a product is aerosolized into a spray, there is a risk of breathing it in. I love SPF on my skin, but I’d prefer to keep it out of my lungs! I like to use SPF mineral powders for re-application on the go, but I hesitate to use them as my primary form of SPF as I don’t think we generally use enough product to get full, even SPF coverage from them.

What’s the deal with scalp-specific haircare products? It seems like there are a lot of scalp oils, masks and massagers on the market right now that purport to help with dryness, oiliness and everything in between. Do they make any kind of difference in the health of that part of your skin?

Like the skin on the rest of your body, your scalp can benefit from exfoliation and hydration. Oils and debris from hair products can build up on the surface of the scalp, which can lead to oiliness and congestion. Clarifying shampoos can help remove this excess buildup. An itchy and dry scalp might be a sign that you are over-washing the hair or using products that are too harsh on the scalp—in this situation, reducing the frequency of hair washing and using sulfate-free, gentle cleansers can be helpful. Finally, if you are noticing dandruff and flaking, look for medicated shampoos with zinc pyrithione or selenium sulfide.

Can you use retinol in the summer if you’re getting regular sun exposure?

It’s true that using retinol can increase your sensitivity to the sun. However, as long as you are diligent about using sun protection during the day, it’s okay to use retinol at nighttime during the summer months.

What’s the best or fastest way to get rid of mosquito bite inflammation?

For itchy bug bites, start by applying a cool compress, which will help reduce swelling and inflammation. Try to avoid scratching your bites, which can break open the skin and lead to infection or scarring. To soothe itching, apply an over-the-counter cortisone cream to the area twice daily for several days, until the itching subsides.

Do you have any favorite foods or supplements that can help support skin health?

I love astaxanthin, a powerful carotenoid that is made naturally by algae—it’s actually what krill and flamingos eat that turns them pink. It is a beauty-from-within antioxidant that supports skin hydration, elasticity, and smoothness. Nicotinamide, a non-flushing form of vitamin B3, is another one of my favorite supplement ingredients. It supports cellular repair and a healthy skin barrier.