According to a new study, using a higher SPF really can make a big difference.

In a group of 199 adult participants, researchers had each person use a different SPF on each side of their face — SPF 50 on one side and SPF 100 on the other side — before spending a day in natural sunlight. The following day, the researchers measured the sun damage present on each side of participants’ faces. Turns out, the SPF 100 really did make a difference.

So, what does this mean for your sunscreen routine? Up your SPF.