"Formula samples" refers to small quantities of a product, usually in liquid form, that are given out for people to try before committing to purchasing a full-sized version. Full definition
Upon my discharge, I was given a bag of free formula samples to take home, even though I chose to breastfeed. (rachelsremedy.com)
If you receive formula samples in the mail, consider donating them to your local food bank before your baby arrives. (cindyandjana.com)
-LSB-...] as a «breastfeeding prize», the impact of formula samples given in the hospital, and ways to know that your health care professional is not supportive of breastfeeding. (phdinparenting.com)