Why Customized Skin Care Matters in Mount Pleasant, SC

Ashley Harwyn, PA-C, ABAAHP  |  Published August 4, 2025  |  Last updated October 6, 2026  |  18 min read

Here is how to pick the ingredients with the clearest evidence, put them on in the order dermatologists recommend, and fit them to your skin type.

The AAD gives different advice for oily, acne-prone skin than for dry skin or rosacea, so two people can start from the same base habits and still need different products.[7][9][10] Below, we walk through which ingredients have earned a place, how to layer and introduce them, how the plan shifts by skin type, and what you can safely leave in the store. If you would rather build it with a clinician, our medical skin care visits in Mount Pleasant and downtown Charleston are one place to do that.

• A good routine is built in layers: gentle cleansing, any treatment product right after, then moisturizer and sunscreen, with makeup last.[1]
• Daily sunscreen has randomized trial evidence. Adults assigned to daily use showed 24% less skin aging over 4.5 years than those who used it when they chose.[4]
• Retinoids, which the AAD calls skin care powerhouses, go on at night, start every other night, and are not for use during pregnancy.[5]
• Add one new product at a time and give it at least six weeks, and sometimes up to three months, before you judge it.[2]
• Dry, oily, acne-prone, rosacea-prone, and darker skin each change which products fit and which to avoid.[7][9][10]
• Using several anti-aging products at once can irritate skin, and the AAD says this often makes the signs of aging more noticeable.[1][2]

What does “customized” skin care actually mean?

Customized skin care means matching a small set of proven ingredients to one person's skin, then adjusting the dose, order, and timing based on how that skin responds. It does not mean a unique formula mixed for you, and it does not mean more steps. In this guide, we describe a personal routine in three layers. The base is a gentle cleanser, a moisturizer if your skin needs one, and sunscreen.[1][3] The second layer is one active ingredient with evidence for your main goal. The third layer, used only when needed, is a prescription or an in-office treatment.

The middle layer is where the AAD's main caution applies. The American Academy of Dermatology (AAD) warns that using too many products may irritate the skin, especially when more than one is an anti-aging product, and that this often makes the signs of aging more noticeable.[1] So taking a product out can matter as much as adding one.

Personalization also covers things a label cannot know. Are you pregnant or planning to be? Do you get red and flushed easily? Do acne marks linger as dark spots on your skin? Are you outdoors on the water most weekends? Each of these can change which products fit, for example because retinoids should not be used during pregnancy and the AAD gives separate advice for rosacea and for dark marks.[3][5][9] Bring those answers to your visit.

Which skin care ingredients have real evidence?

In the sources cited here, sunscreen and retinoids have the clearest evidence for aging skin, a 2024 guideline names the actives for acne, and the AAD recommends moisturizers for dry or sensitive skin.[4][5][6][7][9][10] We did not review the evidence for every other ingredient, so this list is a starting point, not a verdict on everything else.

Broad-spectrum sunscreen. Of the steps in this guide, this one has a multiyear randomized trial behind it for visible aging. In Nambour, Australia, 903 adults younger than 55 were assigned to daily sunscreen or to their usual, discretionary use. The daily group showed no detectable increase in skin aging after 4.5 years, and aging was 24% less than in the discretionary group.[4] The authors flagged some missing data and modest power, so read 24% as an estimate. The AAD recommends SPF 30 or higher, which blocks 97% of the sun's UVB rays; higher numbers block only slightly more, and none blocks 100%.[3]

Retinoids. The AAD describes retinoids as vitamin A-based products.[5] Tretinoin was first approved by the FDA as a topical acne treatment in 1971, and dermatologists soon noticed it also improved tone, fine lines, and wrinkles.[5] Retinol is the over-the-counter member of the family. In a double-blind trial of 36 elderly adults (mean age 87), 0.4% retinol lotion applied to one arm up to three times a week for 24 weeks improved fine wrinkling compared with the same lotion without retinol on the other arm.[6] That was a small study on arms, not faces, but it is controlled evidence that retinol improved fine wrinkling in that setting.

Acne actives. The 2024 AAD acne guideline, built on a systematic review, gives strong recommendations to benzoyl peroxide, topical retinoids, topical antibiotics, and oral doxycycline, and conditional ones to salicylic acid and azelaic acid, among others.[7] It also lists combining topical treatments that work in different ways as good practice.[7]

Moisturizers. For dry skin, the AAD favors creams or ointments over lotions and lists ingredients such as glycerin, hyaluronic acid, dimethicone, petrolatum, and shea butter.[10] For rosacea, the AAD notes that moisturizer is essential whether the skin runs dry or oily.[9]

Vitamin C serums. This is where evidence thins out. A review in Nutrients notes that normal skin contains high concentrations of vitamin C, which supports collagen synthesis and antioxidant protection, and that this is often used as a rationale for adding vitamin C to topical products.[8] The same review says the efficacy of topical vitamin C, compared with getting enough in your diet, is poorly understood.[8]

In what order should you layer skin care products?

The AAD's sequence is simple: wash with a gentle cleanser and pat dry, apply any medicine or treatment product right after cleansing, then moisturizer and sunscreen, and makeup last if you wear it.[1] In that order, treatment goes on right after cleansing and sunscreen goes on with or after moisturizer.[1]

Here is how that plays out across a day:

• Morning: gentle cleanser, an optional treatment step (for example an acne product your plan calls for), moisturizer if you need it, then broad-spectrum SPF 30 or higher as your last skin care layer.[1][3]
• Evening: gentle cleanser, your retinoid or other prescribed treatment, then moisturizer. Retinoids belong at night, because they can make skin more sensitive to the sun.[5]
• Around the eyes: use your ring finger, which the AAD suggests because it is the weakest finger and will not pull too hard on this delicate skin.[1]

Two details trip people up with sunscreen. First, quantity: the AAD advises at least 1 teaspoon for the face alone, about enough to cover the length of your index and middle fingers.[3] Second, timing: apply it to dry skin 15 minutes before you head outdoors, then reapply about every two hours outside, or after swimming or sweating.[3]

If you use a prescription for rosacea or acne, it slots into the same “treatment” position. The AAD's rosacea advice is to put the medicine on first and the moisturizer after it.[9] When two treatment products are part of the plan, ask whether they belong in the same session or on different ends of the day, since the AAD warns that using too many products may irritate the skin.[1]

How do you add a new product without irritating your skin?

Slowly, and one at a time. The AAD's advice for anti-aging products is to start with a single product, because using several at the same time can irritate your skin.[2]

1. Test it first. Apply a small amount to your inner forearm twice a day for four to five days. If your skin looks normal, free of redness, itch, and other reactions, you can apply it to your face.[2] 2. Start low with retinoids. Use the least-intense formula you can find, every other night at first, and build up as your skin allows.[5] Over-the-counter labels are not required to list the percentage of retinol, so “lowest” may take some label reading.[5] 3. Stop anything that stings, burns, or tingles. Those sensations mean the product irritates your skin. The exception is a prescription: some prescription-strength products do sting, so ask your clinician before you stop.[2] 4. Wait before you judge. A moisturizer can plump fine lines within days, but most products need at least six weeks to work, and some up to three months.[2] 5. Keep going if it works. The AAD notes that people often stop a product once they see results, and that continuing it is how you keep them.[2]

Darker skin tones need extra patience. Dermatologists quoted by the AAD warn that in skin of color, irritation from a retinoid can trigger dark marks, and that starting slowly with moisturizer helps reduce that risk.[5] Pregnancy is a firm stop sign: retinoids should not be used while pregnant.[5] If either applies to you, say so before you start a new product.

Drowning in half-used bottles? Call 843-981-0870. Book a skin visit and bring what you use now, so you can ask what to keep, what to drop, and what to add first.

How should your routine change for dry, oily, acne-prone, or sensitive skin?

The base stays put. What shifts is the texture of your moisturizer, which actives you lean on, and which ingredients you avoid. Here is a starting map drawn from AAD guidance and the acne guideline. It is a place to begin a conversation, not a prescription.

A few notes on reading that table. For dry skin, the AAD's tips include habits as well as products: it suggests five to ten minute showers in warm water, patting dry, and putting on moisturizer right away while the skin is still damp.[10] Its list of products to stop for dry skin includes alcohol, fragrance, and retinoids.[10] If you have dry skin and want a retinoid, ask about it at your visit.

Acne-prone skin has a 2024 guideline behind it.[7] That guideline gives strong recommendations to benzoyl peroxide and topical retinoids, and the AAD notes that adapalene, a retinoid, comes in both prescription and over-the-counter forms.[5][7] If you have moderate or severe acne scarring, or breakouts tied to your period or other hormonal changes, the AAD suggests seeing a board-certified dermatologist before trying a retinoid on your own.[5] Prescription options for breakouts are covered on our acne treatment page.

For rosacea-prone or sensitive skin, the AAD's tips favor gentle products. Choose “fragrance-free,” not “unscented,” and pick a cream over a lotion or gel.[9] The AAD's rosacea guidance is blunt about exfoliation: if you exfoliate, stop.[9] Sun is one of the most frequent causes of a rosacea flare-up, and if a sunscreen irritates your skin, the AAD suggests one with zinc oxide, titanium dioxide, or both.[9]

Darker skin tones benefit from a tinted sunscreen. Visible light from the sun can increase skin darkening, particularly in darker skin, and the iron oxide in tinted sunscreens helps protect against it.[3] For marks that have already formed, our hyperpigmentation page explains how melasma, sun spots, and post-acne marks are told apart.

What can most people skip?

Leaving things out is part of the plan, not a shortcut. These are the items the sources cited here give reason to skip or question.

A second or third anti-aging product. Using several at once can irritate skin, and the AAD notes that irritated skin looks older.[2]

Chasing the highest SPF on the shelf. An SPF 70 does not buy you extra time outdoors. The AAD notes that high-number SPFs last the same amount of time as low-number ones, and that many people apply only about 20 to 50% of the amount needed to get the SPF on the label.[3] So the amount you apply, and reapplying it, deserve the attention.[3]

Skin supplements as an anti-aging plan. In the same Australian trial that tested daily sunscreen, beta-carotene supplements had no overall effect on skin aging.[4]

A vitamin C serum you dislike or cannot afford. The review cited here calls the efficacy of topical vitamin C poorly understood, so if your budget or your skin says no, ask whether you need it at all.[8]

Scrubs and harsh exfoliation for sensitive skin. For rosacea, the AAD advises against rubbing or scrubbing and says to stop exfoliating.[9] Toners and astringents fall in the same category for this skin type.[9]

At-home “medical” devices bought online. The AAD warns that lasers and other devices sold online to treat aging are often counterfeit or imported illegally, and that using them can be extremely dangerous to your health.[2]

Expecting a cream to do a procedure's job. The AAD says plainly that creams, gels, and lotions cannot reduce all signs of aging skin.[2] If your concern goes beyond what a topical product can do, ask about in-office options.

When is a home routine not enough, and what does a skin visit add?

A home routine has limits. One is acne that is severe, scarring, or not clearing, where the guideline turns to prescription options such as oral isotretinoin,[7] and another is that creams, gels, and lotions cannot reduce all signs of aging skin.[2] A routine also cannot tell you whether a spot is benign. Our medical skin care page notes that a mole that is new or changing needs a board-certified dermatologist before a facial, a peel, or a laser.

At a skin visit with Ashley Harwyn, PA-C, in Mount Pleasant or at The Longevity Club in downtown Charleston, we ask about the products you use, along with stress, sleep, and diet, and pregnancy plans matter because retinoids should not be used during pregnancy.[5] Any prescription in your plan, such as tretinoin, goes through Ashley.

We carry two professional product lines. ZO Skin Health makes products for many skin types and concerns, and the line uses retinol rather than prescription tretinoin. ALASTIN Skincare is the one we use mainly to support skin as it recovers from procedures such as laser treatments and peels. No single line suits every person, and our ZO page says we would rather tell you that a simpler or cheaper product will do the job than sell you a step you do not need.

When topical care plateaus, you can ask about in-office care such as a chemical peel, which our skin care page describes as going a step deeper for tone and texture, or a facial. For a wider look at common skin concerns and how they are treated, read our post on common skin issues in Mount Pleasant. For how often a skin check makes sense, and how a cancer screening differs from a cosmetic skin analysis, see how often a skin analysis should be performed.

Ashley Harwyn, PA-C PA-C, ABAAHP · Founder, Solcara Health Online

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