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Ethics in science?
Ethics in science?

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1 Clinical trials

Clinical trials are the culmination of a significant amount of research undertaken by chemists, pharmacists and biologists in the discovery of potential new drugs. Following the trial statistical analysis of the results is important because noting the change in one person given a specific treatment is not as valid as noting the same change in two or three people and ideally in a much larger group.

The clinical trials that occur today to test new drugs may consist of hundreds of participants. The number of participants or sample size of an experiment is the number of identical observations (replicates) that can be made of the same test. The statistical analysis of the results is more valid if the sample size is larger.

Any drugs trials conducted today follow very careful guidelines. Scientists running trials have legal obligations that are set out in the Medicines for Human Use (Clinical Trials) Regulations 2004. One of these is anyone taking part in a trial must have a full understanding of the objectives of the research and any risks and potential inconveniences they may experience when taking part.

Activity 1 Researching clinical trials

Timing: Allow approximately 30 minutes for this activity.

In this activity you will look at the clinical trials [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] page on the UK’s National Health Service (NHS) website and then answer the questions that follow.

Navigate around the website reading information that interests you and taking note especially of the following areas:

  • What happens in a clinical trial?
  • How are clinical trials regulated and judged to be ethical?
  • How many phases are there to a clinical trial and what happens in each phase?

Clinical trials assign people randomly to a treatment group or a control group. What does this mean in practice?


  • People in the treatment group are given the treatment being assessed. 
  • People in the control group are given an existing standard treatment, or a placebo if no proven standard treatment exists.

While the treatments are different in the two groups, researchers try to keep as many of the other conditions the same as possible. For example, both groups should have people of a similar age, with a similar proportion of men and women, who are in similar overall health.

In most trials, a computer will be used to randomly decide to which group each patient will be allocated.

Many trials are set up so that nobody knows who has been allocated to receive which treatment, i.e. the trials are ‘blind’ and this helps to reduce the effects of bias when comparing the outcomes of the treatments.

How are clinical trials regulated and judged to be ethical in the UK?


A government agency called the Medicines and Healthcare products Regulatory Agency (MHRA) needs to review and authorise them. The MHRA inspects sites where trials take place to make sure they are conducted in line with good clinical practice.

The Health Research Authority (HRA) works to protect and promote the interests of patients and the public in health research. It is responsible for research ethics committees across the UK. 

All medical research involving people in the UK, whether in the NHS or the private sector, first has to be approved by an independent research ethics committee. The committee protects the rights and interests of the people who will be in the trial.

For each of the statements below, select the correct clinical trial phase.

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The next section describes what was probably the world’s first clinical trial. Undertaken in 1747, it almost certainly would not have been allowed today, although the findings have proved very useful for humans.