New guidelines for direct-to-consumer genetic tests
The guidelines have been drawn up by the Human Genetics Commission (HGC), which hopes to provide the public with greater confidence in genetic testing kits.
Companies - many of which are based in the US - have started to sell DIY testing kits over the internet, providing users with an estimate of their risk of inheriting diseases.
However, the market is currently unregulated and experts are concerned that people can be caused unnecessary concern about their future health without receiving proper counselling.
Under the new industry guidelines, companies will be expected to offer counselling both before and after someone takes a test for serious hereditary diseases, including breast cancer.
They should also explain the possible outcomes of taking a DIY test and provide simple information on how the test works.
Companies will also only be able to make claims that are supported by evidence published in scientific journals.
HGC commissioner Dr Frances Flinter commented: "Direct-to-consumer tests covering everything from hereditary illnesses to ancestry research are now available over the internet from companies in the USA and Europe.
"Some tests can cause considerable surprise or concern to those taking them - or give false reassurance. Some are of doubtful value, to say the least. To cover this international market we need a set of 'off the shelf' principles that can be used everywhere."
Public health minister Anne Milton welcomed the new set of principles, noting that people "deserve to have confidence that the tests they choose are evidence-based and that they fully understand what the results mean".
She added: "I am pleased that the UK's Human Genetics Commission is showing much-needed leadership in cracking down on this."
Hilary Tovey, Cancer Research UK's policy manager, welcomed the publication of the guidelines: "We hope they will go a long way to protecting the public from potentially misleading information about their genetic risk of cancer. With the growing number of genetic tests entering the market, regulation is needed more now than ever before.
"Interpreting the results of genetic tests is a very complex matter and there's a high risk that people will get information that raises anxiety or gives them false reassurances. It's vital that people know about the limitations and consequences of getting a genetic test beforehand, and that results are understandable, cautious and evidence-based. It's also important that people have access to trained professional to help them interpret their results."