The Science Behind Freckles: What Causes Them?

Freckles are one of those skin features that spark curiosity and conversation. Some people have them year-round, others see them pop up only in summer. Some want to fade them, others want to celebrate them. But regardless of how you feel about freckles, understanding what they are and why they happen can help you better care for your skin and appreciate what makes it unique.

Let’s break down everything you need to know about the science behind freckles—from why they show up, to whether you’re born with them, and what (if anything) you can do about them.

What Exactly Are Freckles?

Freckles are small, flat, pigmented spots that usually appear on sun-exposed areas of the skin, such as the face, shoulders, arms, and chest. They can range in color from light tan to reddish- light brown spots and tend to become more noticeable with sun exposure.

Their official name is Ephelides (pronounced eh-fuh-lid-eez).

Freckles aren’t harmful, they aren’t raised, and they aren’t caused by sun damage. They’re simply a visible sign that your skin is producing more melanin in response to UV radiation.

Freckles may appear more prominently in people with light skin tones and fade during the winter when sun exposure decreases.

What Causes Freckles to Form?

Sun exposure and genetics. Freckles are usually formed when your skin produces more melanin—your body’s natural pigment—in response to UV light. Unlike tanning (where melanin spreads out more evenly), freckles are concentrated spots where melanin is overproduced.

Here’s how it works:

• UV exposure stimulates melanocytes (the skin cells that make melanin)
• In some people, those cells called melanocytes respond by creating tiny, focused spots of pigment
• The more sun exposure you get, the more visible the freckles become

Whether or not you get freckles is largely determined by your genes. If you have fair complexion, light eyes, or red hair, you’re more likely to develop freckles because your skin naturally contains less melanin—and compensates by concentrating it in tiny bursts.

Being frequently exposed to the sun without protection also increases your chances.

Are Freckles the Same as Sun Spots or Melasma?

Not quite. While freckles, sun spots, age spots, and melasma all involve pigment, their cause, appearance, and behavior differ.

Freckles (ephelides):

• Appear early in life, fade in the winter, and are more common in fair skin types.

Sun spots (solar lentigines):

• Develop from cumulative sun exposure later in life, and stick around year-round.

Melasma: 

Usually triggered by hormones and UV exposure, and appears as larger patches of pigment (often on the cheeks, upper lip, or forehead).

Freckles are usually harmless and not considered a skin concern, so they don’t require treatment. But if you ever notice a freckle or mole changing shape, color, or size, it’s a good idea to have it checked by a dermatologist—just to be safe. Some changes could be early signs of melanoma or other types of skin cancer.

What’s the Difference Between Freckles and Moles?

Let’s not get it twisted—freckles and moles are not interchangeable. Freckles are small brown spots that appear on areas exposed to the sun and are caused by sun exposure triggering skin cells called melanocytes to pump out more pigment.

Freckles are also flat, fade with less UV, and often show up in clusters, especially if your parents have freckles or you have a skin type that’s likely to develop freckles. Some people even get freckles on their lips (yep, anywhere on your body that sees the sun). 

Moles? Moles can be flat or raised, moles can appear anywhere, and they’re usually more structured than freckles—often larger than freckles and more stable in color. Freckles are usually harmless, but freckles that change or darken rapidly (same goes for moles) deserve a derm’s eye.

And while freckles also tend to fade in the winter, moles don’t budge. So if you’re wondering about the difference between freckles and sun spots, or trying to remove freckles, just know—freckles generally mean your skin’s been vibing with too much UV.

So take the hint, show your skin some love, and wear something that protects your skin from sun damage next time you spend time in the sun.

Can You Prevent Freckles?

While you can’t stop your skin from having the genetic tendency to freckle, you can minimize how many appear—or how dark they get—by protecting your skin from sun damage.

Here’s how:

• Wear SPF 50 daily—even on cloudy days
  
  

• Reapply sunscreen every 2 hours when outside
  
  

• Use a wide-brimmed hat and sunglasses for extra coverage
  
  

• Seek shade during peak sun hours (10am–5pm)
  
  

This doesn’t mean hiding indoors or avoiding the sun entirely—it’s just about giving your skin the support it needs to stay healthy, resilient, and balanced. Prevent freckles from intensifying by choosing products that protect your skin from sun damage.

Can You Fade Freckles If You Want To?

Freckles are natural and nothing to be concerned about. But if you’d like to even out your tone or fade freckles, here are some skin-friendly options:

• Vitamin C: Helps brighten and even skin tone

• Niacinamide: Calms redness, improves clarity, and supports barrier strength

• Mandelic or Lactic Acid: Gentle exfoliation can improve glow and texture

• Retinol: Supports skin renewal, which can help fade pigment over time

• Hydration and Barrier Support: Keeps your skin calm and more resilient

These ingredients don’t erase freckles but can enhance radiance and smoothness, giving you a fresh canvas no matter your freckle pattern.

Products like GOALS or HEROINE contain effective acids and brighteners to improve tone without compromising your barrier. 

Before jumping into intense treatments, it's smart to get a "dermatologist take"—especially if you’ve got sensitive skin.

Can Your Freckles Go Away?

Yes—some freckles may appear temporarily and fade on their own.

Since they are primarily caused by sun exposure, freckles often become lighter or less visible in the winter. If you stop triggering melanin production with UV light, your skin won’t need to cluster pigment in the same way.

But it’s also worth noting that some freckles can become more permanent as you get older, especially with continued sun exposure.

Which Deficiency Causes Freckles?

This is a common myth. Freckles are not caused by a vitamin deficiency.

They’re a genetic and environmental response, not a sign that something is missing from your body. Vitamin C and E can help support skin brightness and resilience, but their absence doesn’t cause freckles.

What Does This Mean for Your Skincare Routine?

If you have freckles, your skin is more likely to be sun-sensitive, so it’s especially important to prioritize:

• Daily sun protection to prevent new freckles from forming
  
  

• Barrier support to keep your skin strong and calm after sun exposure
  
  

• Brightening care to help even tone and support skin clarity
  
  

Look for ingredients like Centella Asiatica (to soothe), Vitamin C (to brighten), and Niacinamide (to strengthen and smooth). Products like LIGHT UP or GOALS are perfect examples of how to protect your skin while still celebrating your freckles.

Final Thoughts

Freckles aren’t a flaw, a sunburn, or something you need to “fix.” They’re a genetic expression of how your skin processes light—just one more way your skin tells its own unique story.

Whether you have a few or a full constellation, the key is to understand what’s happening, support your skin with the right care, and protect it in a way that feels good to you. Because skincare isn’t about erasing your features—it’s about feeling good in your skin, freckles and all.