“We have legislated so experimentation on animals is only permitted when there is no alternative research technique and the expected benefits outweigh any possible adverse effects.” (GOV.UK-policies)In the UK there are strict regulations for animal research which are guided by the Animals (scientific procedures) Act 1986. The main principles surrounding the humane use of animals in medical research are the 3Rs:1. To replace the use of animals with alternative techniques.2. To reduce the number of animals to a minimum and to obtain information from fewer animals.3. To refine the way the experiments are carried out to reduce animal suffering.It is therefore critical that ongoing analysis and assessment of the viability of potential alternatives to animal testing are continuously carried out in order to meet the 3R criteria.Before a drug is released to the public it has to go through three phases:Stage One: preclinical research where drugs are tested using computer models and human/animal cell cultures.Stage Two: preclinical safety assessment research; where Stage One has been passed, testing moves on to safety assessment testing. These tests take place on two different animal species. The animals receive high doses of the new drug for 30 to 90 days. They are carefully monitored for side effects and after the study period pathologists examine their organs for signs of drug toxicity. The drug safety testing is carried out under guidelines mandated by law through the FDA. This stage of safety testing usually takes about 4 years.Stage 3: clinical research where the new drug is tested on humans. Clinical testing is complex and time consuming – it takes an average of 14 years to complete.In order to answer my research question my report will be structured in three sections shown below followed by an evaluative conclusion:1. The use of computer modelling as an alternative to animal testing in drug development.2. The use of cellular research (stem cell research and ‘organ on chips’) as an alternative to animal testing in drug development.3. The moral and ethical arguments surrounding the use of animal testing.