New research has found that young women who drink caffeinated beverages on the daily experience changes in hormone levels.How much will your Starbucks and Diet Coke addictions affect your chemical ladyhood? Like being arrested in Arizona, the way caffeine treats your lady hormones depends on your race.

Researchers examined 250 young, female test subjects who drank about a cup of coffee per day and found that drinking caffeine caused subjects’ estrogen levels to fluctuate. On a small scale, this isn’t necessarily good or bad, but on a large scale— say, if you’re one of those people who polishes off an entire pot of eyebrow-singeing coffee before 10 am every day— they’re not sure yet.