Costco shoppers in Northern California got a refreshing surprise when they bumped into Michelle Obama, who was in the store giving her new healthy drink, Plezi Fizz, quite the sparkling endorsement.

In a viral TikTok, the former First Lady was spotted at a Livermore Costco, raving her Plezi Fizz is not only healthy and calorie-free … but also tastes pretty darn good.

Shoppers were clearly buzzing as they gathered around Michelle, eagerly soaking up her Plezi Fizz pitch … while her serious-looking bodyguards stood by.

A Costco employee told Daily Mail the event to promote her business took place Tuesday. The drink is available to buy at Costco.

Michelle is the co-founder of Plezi Nutrition, with the brand focusing on making food and beverages healthier … and has joined forces with actress Kristen Bell, who’s a mother herself, as an investor and brand partner.