What about Sunscreen and Lotion?
While sunscreen is an absolute necessity when you're spending prolonged time out in the sun, a fresh piercing or tattoo is technically considered an open wound. In general, it's best to avoid putting any sort of cosmetic lotion or sunscreen on any cut or injury, let alone a piercing or tattoo.
It may be tempting to remove a new piercing to properly apply sunscreen, but this is a definite no-no. Keep your body jewelry in the piercing until it's fully healed.
We want our piercings to heal as quickly and as safely as possible, so introducing any sort of chemical into the equation is almost always a bad idea. Sunscreens and lotions can have any number of nasty ingredients (like fragrances, alcohols, waxes, or other chemicals) that may have negative effects on a piercing or tattoo, including drying effects or irritating tendencies. Worst case scenario - you may end up with an infection.
Still, applying sunscreen is an absolute must. Take care not to get any of the sunscreen in your actual piercing hole or on your piercing jewelry. Your body will thank you for being careful.
An alternate method is to simply make sure your piercing is covered by a bandage, gauze pad, or other cloth - tan lines are a small price to pay for a healthy and aesthetically pleasing piercing.