Age spots are almost entirely caused by UV exposure, which means they’re largely preventable. The dark, flat patches that show up on hands, face, shoulders, and arms develop when years of sun exposure push certain skin cells to overproduce pigment. Preventing them comes down to limiting how much UV radiation reaches your skin, both outdoors and indoors.
Why Age Spots Form
Age spots develop when the cells responsible for skin color start behaving abnormally. In affected areas, these pigment-producing cells increase in number, and each individual cell ramps up its pigment output well beyond what healthy skin produces. The surrounding skin also releases chemical signals that further stimulate pigment production, creating a self-reinforcing cycle. This isn’t a one-time event. It’s the cumulative result of repeated UV exposure over years, which is why these spots tend to appear after age 40 or 50, even on skin that never burned badly.
UVA radiation is the primary driver. Unlike the shorter-wavelength rays that cause sunburn, UVA penetrates deeper into skin and triggers the long-term structural changes that lead to permanent pigment deposits. This distinction matters because UVA exposure adds up in ways most people don’t notice: through car windows, office windows, and on overcast days when the sun doesn’t feel strong.
Sunscreen: The Single Most Effective Step
Daily broad-spectrum sunscreen with at least SPF 30 is the foundation of age spot prevention. The American Academy of Dermatology recommends SPF 30 as the minimum. “Broad-spectrum” is the key word on the label, because it means the product filters both UVA and UVB rays. An SPF 50 sunscreen that only blocks UVB won’t protect against the deeper radiation that drives pigmentation.
Apply it to your face, neck, ears, and the backs of your hands every morning, even if you’re mostly staying inside. Reapply every two hours when you’re outdoors, and immediately after swimming or sweating. Most people use far less sunscreen than the amount tested in labs, so be generous. For your face alone, about a nickel-sized amount is the right ballpark.
Why Windows Don’t Protect You
Standard window glass blocks nearly all UVB rays but lets up to 74% of UVA rays pass through. If you sit near a window at work, drive frequently, or spend time in a sunlit room, your skin is absorbing meaningful UV exposure without any of the cues (warmth, redness) that would normally prompt you to take action. This is one reason age spots sometimes appear more heavily on the left side of the face in countries where people drive on the right. Wearing sunscreen daily, even on indoor days, addresses this hidden source of cumulative damage.
Clothing That Actually Blocks UV
Sun-protective clothing is more reliable than sunscreen for the areas it covers, because it doesn’t wear off, wash off, or get applied unevenly. Fabrics are rated on a UPF scale: UPF 15 blocks about 93% of UV radiation, UPF 30 blocks roughly 97%, and UPF 50+ blocks 98% or more. The Skin Cancer Foundation only recommends garments rated UPF 50 or higher.
If you don’t want to buy specialty clothing, you can still improve your protection with what’s already in your closet. Tightly woven fabrics block more UV than loose weaves. Synthetic fibers like polyester and nylon outperform cotton and hemp. Darker colors (black, navy, deep green, burgundy) absorb UV more effectively than light colors. A loose white cotton t-shirt might only provide UPF 5 to 7, while a dark polyester shirt could offer UPF 30 or more without any special treatment.
A wide-brimmed hat protects the face, ears, and neck far better than a baseball cap. Pair it with UV-blocking sunglasses to protect the thin, vulnerable skin around your eyes, where age spots and sun damage commonly appear.
Time Your Outdoor Exposure
UV intensity peaks from late morning through mid-afternoon. The EPA recommends a simple rule: if your shadow is shorter than your height, UV levels are high. During summer months, this window roughly spans 10 a.m. to 4 p.m. in most of the continental U.S. Planning outdoor exercise, errands, or yard work for early morning or late afternoon significantly reduces your total UV dose over the course of a year. When you are outside during peak hours, seek shade whenever possible.
Antioxidants as a Second Line of Defense
Topical antioxidants won’t replace sunscreen, but they add a measurable layer of protection against the UV damage that triggers pigment changes. A well-studied combination of 15% vitamin C, 1% vitamin E, and ferulic acid roughly doubled the skin’s resistance to UV-induced damage compared to vitamins C and E alone, providing about eight times the protection of unprotected skin. This was measured by reductions in sunburn cells and DNA damage, both precursors to the kind of cellular changes that lead to age spots.
Apply a vitamin C serum in the morning under your sunscreen. The antioxidants neutralize some of the free radicals that UV generates in skin cells before they can signal pigment-producing cells to ramp up. This combination is most effective when applied consistently over weeks and months rather than sporadically.
Oral Supplements Worth Knowing About
An extract from a tropical fern called Polypodium leucotomos has shown measurable UV-protective effects when taken by mouth. In a clinical study of 22 subjects, the supplement reduced UV-induced redness and inflammation in the majority of participants, with skin biopsies showing decreased damage in all 22. The protective effect kicked in within two hours of taking a dose. It works as an internal anti-inflammatory, reducing the skin’s overreaction to UV exposure. This supplement is available over the counter and is sometimes marketed under brand names as a “sun pill,” but it’s not a substitute for sunscreen. Think of it as one more tool, particularly useful for people who burn easily or spend significant time outdoors.
Check Your Medications
Certain medications make your skin more reactive to UV, accelerating pigment changes and increasing age spot risk. Some antibiotics in the tetracycline family are well-documented photosensitizers that can trigger skin darkening both through direct chemical reactions in the skin and through post-inflammatory pigment deposits. The heart medication amiodarone can accumulate in the skin over time and cause noticeable discoloration. Other common culprits include certain diuretics, anti-inflammatories, and some psychiatric medications.
If you take any prescription medication long-term, check whether photosensitivity is listed as a side effect. If it is, that doesn’t mean you should stop the medication. It means you need to be especially diligent about sun protection while taking it, because your threshold for UV damage is lower than normal.
Building a Daily Routine
Prevention works best as a set of habits rather than a single product. A practical daily approach looks like this:
- Morning: Apply a vitamin C serum, then a broad-spectrum SPF 30+ sunscreen, on your face, neck, ears, chest, and hands.
- Getting dressed: Choose darker, tightly woven fabrics when you’ll be outdoors. Grab a hat and sunglasses for any extended time outside.
- Midday: Reapply sunscreen if you’ve been outside for two hours or more. Seek shade during peak UV hours.
- Year-round: Wear sunscreen even in winter and on cloudy days. Up to 80% of UV rays penetrate cloud cover, and snow reflects UV back onto exposed skin.
Age spots take decades of UV exposure to develop, so every year of consistent protection matters. People who start a rigorous sun protection routine in their 20s or 30s dramatically reduce their likelihood of developing spots later. But even starting in your 40s or 50s slows the formation of new spots and helps prevent existing ones from darkening further.