How to Deal With Hyperpigmentation and Dark Spots in Summer (Without Wrecking Your Skin)

Every summer, my inbox fills up with the same question in slightly different words. "My dark spots are coming back. What do I do?"

If you've spent the winter and spring carefully treating melasma, sun damage, post-acne marks, or that one stubborn freckle that turned into a continent, summer can feel like a betrayal. The spots you thought were fading reappear. New ones show up. The mirror starts to feel like a daily ambush.

Here's the honest version of what's happening, what actually works, and what you should reasonably expect from any skincare routine, including mine.

What Hyperpigmentation Actually Is

Hyperpigmentation is the umbrella term for any patch of skin that's darker than the skin around it. It happens when melanocytes (the pigment-producing cells in your skin) make extra melanin in response to a trigger. The main triggers are UV radiation, visible light, hormones, inflammation, and heat.

The three forms you're most likely dealing with:

Sun spots (solar lentigines) are the small to medium brown spots that accumulate over decades of sun exposure. They tend to show up on the face, chest, hands, and forearms. They're the most common form of hyperpigmentation in adults over 40 and they're almost entirely UV-driven.

Melasma appears as larger, often symmetrical patches on the cheeks, forehead, upper lip, or jaw. It's strongly influenced by hormones (pregnancy, birth control, perimenopause) but the trigger that brings it to the surface and keeps it there is light exposure. Melasma is famously stubborn.

Post-inflammatory hyperpigmentation (PIH) is the dark mark left behind after a breakout, a bug bite, a scratch, or any inflammatory event on the skin. It's not scarring. It's pigment that was deposited as part of the inflammatory response and is slowly working its way back out.

All three darken in summer. All three respond to the same first principle: protect first, treat second.

Why Summer Makes Everything Worse

You probably know UV light triggers melanin production. What gets less attention is the role of visible light, especially the high-energy blue-violet end of the spectrum.

Recent research has been clear and consistent: visible light, particularly the wavelengths between 400 and 500 nanometers, stimulates pigmentation in a way that traditional UV-only sunscreens don't block. A 2013 randomized trial found that adding visible light protection to a melasma routine produced significantly better results than UV protection alone, even when both patients used 4% hydroquinone (Castanedo-Cazares et al.). A 2025 study in Photodermatology confirmed that tinted sunscreens containing iron oxides can block over 93% of visible light, with darker formulations reaching up to 98% (He et al., 2025).

This matters because:

• UV rays are stronger in summer
• You spend more time outside
• Heat itself can worsen melasma independent of light exposure
• Visible light from the sun is intense enough to drive pigmentation even when you're "just running errands"

So if your routine has been holding through winter and falling apart in summer, this is usually why. Your skin needs more protection, and a different kind of protection, than it does the rest of the year.

Setting Reasonable Expectations

I want to be honest with you before we go any further.

No skincare product, mine or anyone else's, will erase deep or long-standing hyperpigmentation in a single season. Topical treatments work gradually. Most studies on the best-evidenced topical ingredients (including prescription hydroquinone, the actual gold standard) show meaningful results at 8 to 12 weeks of consistent use, with continued improvement over 6 months or more.

Realistic timelines for topical treatment:

• Surface-level PIH from a recent breakout: often fades meaningfully in 4 to 8 weeks
• Sun spots that have been there for years: typically take 3 to 6 months of consistent treatment to soften, sometimes longer
• Melasma: the most stubborn category. Even with prescription treatment, the goal is usually management, not erasure. Relapse with sun exposure is common.

If you've spent any time on TikTok watching someone's "dark spot disappear in 7 days," that wasn't a 7-day result. That was filtering, lighting, or a procedure they didn't mention. Real pigment correction is slow, cumulative, and dependent on protecting your skin every single day.

The flip side: the routine you build now to protect your skin this summer prevents future damage from accumulating. Sun protection compounds the same way pigment damage does. It's the most cost-effective anti-aging investment available.

The Summer Hyperpigmentation Strategy

This is the framework I follow personally and recommend to customers. It has three layers: prevent, treat gently, support recovery.

Layer 1: Prevention (the part that does 80% of the work)

Daily broad-spectrum SPF, every single day, reapplied every two hours of sun exposure. Non-negotiable. SPF 30 minimum, SPF 50 if you're outdoors a lot.

Look for a tinted sunscreen with iron oxides if pigmentation is your main concern. The clinical evidence here is strong. Iron oxides physically block visible light in a way that mineral filters alone don't. This is one of the rare cases where the research is so consistent that I'd consider it a genuine summer must-have for anyone with melasma or stubborn dark spots. (Stark doesn't make sunscreen, so I'll point you to Lab Muffin's reviewed picks rather than send you to a random brand.)

Physical protection: wide-brim hat, sunglasses, shade when you can take it, especially between 10am and 4pm. A good hat does more than your SPF reapplication will.

Skip the heat exposure when you can. Saunas, hot yoga, long sun-soaked patio sessions: all of these can worsen melasma even without direct sun on your face. Your skin doesn't distinguish between UV-induced inflammation and heat-induced inflammation as much as you'd think.

Layer 2: Treat Gently with Antioxidants and Stable Vitamin C

This is where City Light Daytime Oil fits in. City contains tetrahexyldecyl ascorbate (also called THD ascorbate), a lipid-soluble derivative of vitamin C that has become one of the better-studied options for pigmentation and photodamage.

A few reasons I built City around this form of vitamin C specifically:

• L-ascorbic acid (the form most "vitamin C serums" use) requires a low pH below 3.5 to be effective on skin, which is irritating for many people, and it's notoriously unstable in light, heat, and air — meaning your $90 serum is often half-oxidized before you finish it
• Tetrahexyldecyl ascorbate is stable, doesn't require a low pH, and penetrates the stratum corneum more effectively than L-ascorbic acid (a 2019 in vitro study showed approximately 110% greater penetration at six hours and 150% greater at 24 hours)
• It's been shown in multiple clinical studies to reduce hyperpigmentation, support collagen, and protect against free radical damage from UV and visible light
• It plays nicely with sunscreen and doesn't sting on summer-sensitized skin

Applied under your SPF in the morning, City layers protection on top of protection. The vitamin C neutralizes free radicals that UV exposure generates even through sunscreen (no sunscreen blocks 100% of anything), and supports your skin's own repair work.

Petrichor Antioxidant Mist earns its place in summer for a different reason. Heat, humidity, and increased oil production can push acne-prone skin toward more breakouts, and breakouts create the next round of post-inflammatory hyperpigmentation. Petrichor's gentle antimicrobial botanicals (white willow bark, Zinc PCA) help interrupt that cycle without inflaming the skin further. Used on damp skin after cleansing, especially on breakout-prone areas, it supports clearer skin without the harshness that triggers more PIH.

Layer 3: Support Recovery at Night

Nighttime is when your skin does its actual repair work, and a few targeted choices accelerate it.

Eclipse Enzyme Cleanser twice a week, as a 10-minute mask if you want to go deeper. The papaya and pineapple enzymes gently encourage cell turnover, which helps surface-level pigmented cells move along faster. "Gentle" matters here. Aggressive exfoliation (glycolic acid, manual scrubs, harsh retinoids) in summer is one of the fastest ways to worsen hyperpigmentation, because the resulting inflammation triggers more melanin production. Enzymes are the slow, low-irritation approach, which is exactly what you want when your skin is already dealing with summer stress.

Deep Midnight at night is where the longer-term work happens. It's formulated with botanical oils rich in vitamin A precursors and omega fatty acids (rosehip seed oil, sea buckthorn) that support skin renewal and barrier repair while you sleep. A repaired, resilient barrier responds better to everything: less reactive to sun, less prone to inflammation, faster to recover from breakouts. Over months, this is what determines whether your pigmentation gets better or stays stuck. *Only start a new retinol treatment in the summer if your skin is already accustomed to retinoids.*

The 6-Step Summer Routine

Morning:

1. Rinse with water or do a light cleanse with Eclipse if your skin feels oily
2. Petrichor mist on damp skin
3. City Light Daytime Oil pressed in
4. Broad-spectrum tinted SPF with iron oxides

Evening:

1. Cleanse (double cleanse if you wore SPF and makeup, which you should have)
2. Petrichor mist
3. Deep Midnight oil
4. Optional: a thin layer of cleansing balm left on as an overnight mask if your skin feels depleted

Twice a week, in place of cleanser: Eclipse as a 10-minute treatment mask

What Not to Do in Summer

A short list of things that will set you back:

• Aggressive exfoliation. Save the glycolic acid peels for fall.
• Starting a new retinoid right now. If you're already using one and your skin tolerates it, fine. But summer is not the time to introduce retinoids if you're prone to pigmentation. Wait until October.
• Skipping SPF "just for a quick errand." 15 to 20 minutes of midday summer sun is enough to trigger melasma on darker skin types (per Dr. Pearl Grimes's research).
• DIY lemon juice, baking soda, or other internet-recommended brightening hacks. These cause inflammation, which creates more pigmentation, which sends you in the opposite direction of where you want to go.
• Comparing your skin to a 22-year-old's on social media. Different biology, different lighting, different filter, different conversation.

When to See a Dermatologist

If your hyperpigmentation is sudden, asymmetric, growing, or has irregular borders, see a dermatologist. Always. Skincare blog posts (including this one) are not a substitute for professional evaluation of anything that looks unusual.

If your melasma is severe and topical management isn't enough, a dermatologist can discuss prescription options like hydroquinone, tranexamic acid, or low-energy laser treatments. Some of these can be done during summer with careful sun avoidance. Others are better saved for darker months.

A good dermatologist will also be honest with you about what topical and procedural treatments can realistically achieve.

—Jess

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References

• Castanedo-Cazares, J. P., et al. (2014). Near-visible light and UV photoprotection in the treatment of melasma: a double-blind randomized trial. Photodermatology, Photoimmunology & Photomedicine, 30(1), 35-42.
• He, X., et al. (2025). Visible Light Protection: An Updated Review of Tinted Sunscreens. Photodermatology, Photoimmunology & Photomedicine, 41(4).
• Grimes, P., et al. (2020). Impact of Iron-Oxide Containing Formulations Against Visible Light-Induced Skin Pigmentation in Skin of Color Individuals. Journal of Drugs in Dermatology, 19(7), 712-717.
• Maloney, S., et al. (2026). Hydroquinone-Free, Tetrahexyldecyl Ascorbate Antioxidant Serum for Hyperpigmented and Photodamaged Skin. Journal of Cosmetic Dermatology.
• Iliev, D., & Wolfer, L. U. (2021). Tetrahexyldecyl Ascorbate (THDC) Degrades Rapidly under Oxidative Stress but Can Be Stabilized by Acetyl Zingerone. PMC8395926.
• Nathan, N., & Manstein, D. (2020). Tinted sunscreens: Benefits beyond an attractive glow. Harvard Health.
• Demystifying hyperpigmentation: Causes, types, and effective treatments. Harvard Health (2024).
• Lab Muffin Beauty Science — recommended for current SPF reviews and ingredient deep-dives.