Please don't take this! I took it for about 6 months. Initially I felt terrible, then I improved (gut symptoms). However, I started to suffer anxiety type symptoms in the night (tight chest, air hunger, more nausea). It became extreme with muscle twitching in the face and body. My intense research uncovered how symprove contains 4 types of probotic - including acidophilus and enteroccus feacium, high levels of which are already found in m.e cfs. There is a big study about this finding. The symptoms I was suffering from were classic acidosis type symptoms. I stopped the probiotic and the symptoms have definitely improved but not completely - this probiotic is very strong and very capable of settling and establishing within the gut. Once there it is very hard to eradicate. I've had an awful time. I should also note, where my stomach had initially improved, it soon became bad again during and after ceasing symprove. I contacted the company to stress how people with m.e should be warned about their product, but they would accept no responsibility for what their product did to me. I still suffer neuro symptoms to this day (i stopped it 1 1/2 years ago). It angers me that they can promote such a powerful product for everyone and anyone, without knowing the health consequences to some illnesses. Dont touch it people from phoenix rising. This is not good stuff for us! (My m.e is very gut based - the gut being probably my most prominent symptom overall).