Introduction:- For couples undergoing assisted reproduction, a plethora of adjuncts are available; these are known as ?add-ons?. Most add-ons are not supported by good quality randomised trial evidence of efficacy, with some proven to be ineffective. However, estimates suggest that over 70on, often at extra cost to the patient. This study has three aims. First, to undertake a survey of in vitro fertilisation (IVF) clinics in the UK to ascertain which add-ons are being offered and at what cost. Second, to undertake qualitative semi-structured interviews of patients, clinicians and embryologists, to explore their opinions and beliefs surrounding add-ons. Third, to review the interpretation of the Human Fertilisation and Embryology Authority traffic light system, to better understand the information required by IVF patients, clinicians and embryologists when making decisions about add-ons. Methods and analysis:- All UK IVF clinics will be contacted by email and invited to complete an online survey. The survey will ask them which add-ons they offer, at what cost per cycle and how information is shared with patients. Semi-structured interviews will be conducted in the UK and Australia with three groups of participants: (i) fertility patients; (ii) clinicians and (iii) embryologists. Participants for the interviews will be recruited via social media channels, website adverts, email and snowball sampling. Up to 20 participants will be recruited for each group in each country. Following an online consent process, interviews will be conducted via video-conferencing software, transcribed verbatim and data subjected to inductive thematic analysis. Ethics and dissemination:- Ethical approval has been granted by the Universities of Sheffield, Bath Spa and Melbourne. Findings will be published in a peer-reviewed journal and disseminated to regulatory bodies in the UK and Australia. A lay summary of findings will be shared via Fertility Network, UK.