An extra shot, less milk
Starbucks’ Iced Shaken Espresso is espresso shaken over ice with a splash of milk, and it carries one more shot than an Iced Caffè Latte at every size: 150 mg in a Tall (against 75 mg for the latte), 225 mg in a Grande (against 150 mg), and 300 mg in a Venti (against 225 mg). With far less milk diluting the shots, it reads stronger cup for cup, and the numbers back that up.
Brown sugar oatmilk version runs higher still
The Iced Brown Sugar Oatmilk Shaken Espresso uses the same shot counts as this drink but swaps in blonde espresso, which carries 85 mg a shot instead of 75 mg, reaching 255 mg in a Grande, 30 mg more than the plain version.
A newer style built for iced drinking
Starbucks introduced the shaken espresso format specifically as an iced drink, shaking the shots with ice to chill and slightly aerate them rather than simply pouring hot espresso over ice, which can taste diluted and bitter. That preparation method is also why it isn’t offered hot; there’s no equivalent warm version with the same name and shot structure.
Where it fits in a day
A Grande, 225 mg, is over the 200 mg single dose EFSA assessed as safe for healthy adults. A Venti, 300 mg, is three-quarters of the 400 mg daily figure the FDA cites for healthy adults, on its own. In pregnancy, where ACOG uses a 200 mg daily ceiling, even a Tall already uses three-quarters of the day’s allowance.