Background IVF add-ons are techniques, medicines or procedures used in addition to standard IVF with the aim of improving the chance of success. The United Kingdom's IVF regulator, ( the Human Fertilisation Embryology Authority (HFEA) developed a traffic light system to categorise add-ons as either green, amber, or red, based on results of randomised controlled trials. Method Qualitative interviews were undertaken to explore understanding and views of the HFEA traffic light system among IVF clinicians, embryologists and IVF patients across Australia and the United Kingdom. Results A total of 73 interviews were conducted. Overall, participants were supportive of the intention of the traffic light system, however many limitations were raised. It was widely recognized that a simple traffic light system necessarily omits information which may be important to understanding the evidence base. In particular, the red category was used in scenarios that patients viewed as having different implications for their decision-making, including 'no evidence' and 'evidence of harm'. Patients were surprised at the absence of any green add-ons and questioned the value of a traffic light system in this context. Many participants considered the website a helpful starting point, but desired more detail, including the contributing studies, results specific to patient demographics (e.g., <35 years and >35 years), and inclusion of more options (e.g. acupuncture). Overall, participants believed the website to be reliable and trustworthy, particularly due to the Government affiliation, and despite some concerns regarding transparency and an overly cautious regulator. Conclusion Participants identified many limitations with the current application of the traffic light system. These could be considered in any future updates to the HFEA website and for others developing similar decision support tools.