You can make kefir yourself either from the Body Ecology starter kits or from the actual grains. If doing this is simply impossible for you, there are several quality brands sold in health food stores as well as some supermarkets. The starter kits can be purchased from the website that makes them. They’re very easy to use. http://bodyecology.com/digestive-health-kefir-starter.html#sthash.qeFkgndM.dpbs
Helios Organic kefir, Greek Gods, Lifeway Greek Kefir, Green Valley, Redwood Hill (made from goat’s milk), So Delicious (made with coconut milk), and Green Valley are some of the more notable brands of bottled kefir.