Melanoma, the deadliest form of skin cancer, is becoming increasingly prevalent, with the Skin Cancer Foundation predicting a 10.6% jump in U.S. diagnoses in 2026. Dermatologists are warning that many people make common mistakes when using sunscreen, potentially increasing their risk of painful sunburns and the deadly disease.

Research indicates that experiencing five or more sunburns doubles the risk of developing melanoma. Even a single blistering sunburn during childhood or adolescence can significantly elevate this risk. Melanoma, which literally means "black tumor," can manifest as a new mole, a changing mole, or a spot with an irregular shape, border, or color. Its danger lies in its potential to spread rapidly to other parts of the body if not detected early.

A significant factor contributing to melanoma is sunburn, and dermatologists emphasize that consistent daily sunscreen use can dramatically lower the risk of melanoma and other skin cancers. However, simply applying sunscreen may not be sufficient.

Dr. Shari Lipner, a dermatologist at Weill Cornell Medicine and NewYork-Presbyterian, has identified eight common errors people make with sunscreen.

Common Sunscreen Blunders

One of the most frequent mistakes is using too little sunscreen. Studies suggest that most individuals apply only 20% to 60% of the recommended amount, leaving them exposed to sunburn, skin cancer, and premature aging. Lipner advises using about 1 ounce of sunscreen to cover the entire body, which is roughly the amount that fits in a shot glass. Alternatively, the "teaspoon rule" can be applied: one teaspoon for the face and neck, one for each arm, one for the chest and abdomen, one for the back and shoulders, and two for each leg.

Another prevalent error is insufficient reapplication. Lipner notes that about 60% of people do not reapply sunscreen often enough. One study found that every participant who did not reapply sunscreen got sunburned, while those who reapplied every one to two hours remained protected. Sunscreen should be reapplied every two hours and immediately after swimming, sweating, or towel drying. Even "water resistant" formulas typically only last for 40 minutes.

Applying sunscreen too late is also a concern. Chemical and broad-spectrum sunscreens require about 15 minutes before sun exposure to allow for absorption into the skin. Mineral sunscreens, however, form a barrier on the skin and begin protecting immediately upon application.

Many individuals also forget to apply sunscreen to easily overlooked areas such as the neck, nose, chin, and the skin around the eyes, despite melanoma's potential to appear on ears, lips, and even eyelids.

Mistakes in application technique include rubbing sunscreen in too vigorously. This can cause the sunscreen to become lodged in skin creases, potentially missing certain areas and reducing effectiveness by as much as 25%. Gently spreading or patting sunscreen onto the skin in an even layer and allowing it to dry is recommended.

Reliance on spray and stick sunscreens can also be problematic. While convenient, it is difficult to gauge adequate application, and these forms are more prone to leaving gaps and uneven coverage compared to lotions and creams, which offer more reliable protection.

A false sense of security can lead some people to spend excessive time in the sun even after applying sunscreen, neglecting other crucial protective measures. Lipner stresses that even with sunscreen, limiting sun exposure, seeking shade, and wearing protective clothing and sunglasses are essential.

Perhaps the most significant mistake, according to Lipner, is skipping sunscreen altogether. Exposure to UV rays is the single most important modifiable risk factor for skin cancer, making the omission of sunscreen a substantial risk.

Sunscreen Best Practices

To ensure adequate protection, Lipner offers three key recommendations:

  • Choose the right product: Opt for a broad-spectrum sunscreen with an SPF of 30 or higher. A higher SPF can offer a buffer against inadequate application.
  • Be mindful of timing: Sunscreen is most critical between 10 a.m. and 4 p.m. when UV rays are strongest, but skin damage can occur throughout the day.
  • Check the UV Index: Consulting the UV Index before going outside can help individuals make informed decisions about sun protection, such as applying sunscreen or seeking shade.