Simply Cardio - This is 200mg per tablet of bovine heart tissue. Heart tissue is sometimes used by people with low blood pressure, overwhelming fatigue, people who need strength, people who feel cold, and athletes interested in improved performance. It is normally best not to take heart tissue late in the day (at breakfast and lunchtime is best for most people), as any heart glandular support product can affect sleep if taken late in the day . Heart tissue, if appropriate, tends to show its benefits rather quickly (within a week or two for most people), though this varies. Heart tissue has historically also been used as an aid in glucose uptake and the manufacture of ATPs .