Starbucks is going rBST-free. The world’s largest specialty coffee retailer says it will no longer use dairy products made with the artificial growth hormone at coffeehouses in a number of regions around the country. It is investigating a similar change at stores nationwide.

The announcement comes less than a month after Starbucks said it was halfway through a plan to phase out artery-clogging trans fats at company-owned U.S. stores.

As of this January, 37% of milk, half-and-half, whipped cream and other liquid dairy products that Starbucks purchases are produced with rBST. That’s an increase of about 27% from the 2006 fiscal year, a company spokesperson said.

The change affects stand-alone Starbucks stores in Washington, Oregon, Idaho, Alaska, Montana and New Mexico, and Texas, along with Northern California and New England. The company also is examining plans to phase such products out of all stores nationwide, but hasn’t yet committed to making the larger change, a spokesperson said.