A new "checkout" button for instant purchasing launched in a beta version of the app in the US with a limited number of businesses, according to the popular image-centric messaging service.
Facebook-owned Instagram on Tuesday made a move into potentially lucrative e-commerce by adding an option to buy products shown off in posts by selected brands.
"We're introducing Checkout on Instagram," the Silicon Valley based division of Facebook said in an online post.
"When you find a product you love, you can now buy it without leaving the app."
Tapping the checkout button will allow shoppers to select options such as size or colour and then pay for items without leaving the Instagram app.
Previously, people inspired to buy products featured in Instagram posts had to follow links to outside online shopping sites.
Information entered for an initial purchase will be stored for future use, according to Instagram.
It remained to be seen how people would feel trusting information such as credit card details to a service owned by Facebook, which has been hit with waves of criticism for its handling of personal data.
Brands taking part in the checkout feature included Adidas, Burberry, Dior, H&M, Nike, Oscar de la Renta, Prada, and glasses retailer Warby Parker.
Facebook makes the bulk of its money from digital advertising but has dabbled with e-commerce in the past. It has pitched its Messenger service as a communication platform for shops or brands to connect with customers.