Certain studies indicate that heading out into the sun after applying or drinking several glasses of lemon juice on your skin can cause blisters and dark spots. This condition is called plant-solar dermatitis and is a worse form of sunburn. The culprits are the chemicals in lemon juice, called psoralens, which interact with sunlight and cause the burn.

In another study, citrus consumption was linked to an increased risk of melanoma (skin cancer). The effect was attributed to the presence of psoralens in most citrus fruits. However, further studies are needed to better understand the effects of citrus fruits on skin health.