If you’re watching your calories, you might want to skip the trip to Starbucks this weekend.

People all over the country have been lining up for the pink, sparkly Unicorn Frappuccino. The coffee giant describes the limited edition treat as sweet, fruity and "pleasantly sour." The bright Frappuccino even changes colors, with a blue swirl mixing into the pink base to make purple.

But that "magic" comes with an overload of sugar. The standard 16 oz. size, known as grande at Starbucks, contains a whopping 59g of sugar if ordered with whipped cream.

That's equivalent to eating approximately 15 sugar cubes.

“Sugar is listed as an ingredient five times in the ingredient list. There are so many different sources of sugar,” Tox Doc Dr.Noreen Khan-Mayberry said. “I mean, you talk about a glycemic swing that is out of this world.”

Skipping the whipped cream won't make much of a difference at 55g of sugar, which is only about one less sugar cube.

One grande Unicorn Frappuccino holds about double of the recommended daily added sugar limit for both men and women, according to the American Heart Association.

Not to mention, ordering a Grande will set you back 410 calories and 140 of those calories are from fat.

So if you're going to treat yourself with the frosty glitter-bomb, get ready for a very high sugar rush.

“This is really bad for someone to drink on a regular basis,” Dr. Khan Mayberry said. “I’m really glad these are available for a limited time.”

Not convinced? Better hurry then. The Unicorn Frappuccinos are only available till Sunday.