The testing of the feature was revealed by social media commentator Matt Navarra on Twitter, crediting journalist Oriol Salvador.
The app currently allows approved users to tag products in posts, featuring up to five items in a single image or video and up to 20 products in multi-image posts.
However, the ability to mention products in the caption of a post has also rolled out on the platform, with fashion designer Victoria Beckham tagging one of her moisturising products in the description of a video.
new on Instagram? tagging products in the COPY of an Instagram feed post… https://t.co/0gIBIPq5UV
— Matt Navarra | 🚨 #StayAtHome (@MattNavarra) June 17, 2020
The news follows the announcement of Instagram Shop in May, with the feature first launching in the US in the summer.
Writing in a blog post, Facebook said the tool is “a new way to discover and buy products you love in Instagram Explore”.
“You can get inspired by collections from @shop, browse selections from your favorite brands and creators, filter by categories like beauty and home, and purchase the looks you love all in one place.
“And later this year, we’re adding a new shop tab in the navigation bar, so you can get to Instagram Shop in just one tap.”
It has not yet been revealed when the product tag feature for captions or Instagram Shop will be rolled out more widely.