To ensure the bio availability of extracts in animal system is not easy process. First identify or decide accepted bio marker or important phyto chemical of particular herbal extract and it's qualitative and quantitative values, record these values. The extract is to be given to the experimental animal for particular days say 3,6,9,12 or more weeks for particular pharmacological action or actions. There after take the blood samples after 24, 48, 36 hours and separate plasma and test the plasma for particular phyto chemical values, compare with presence in extract sample and plasma samples.