<b>Introduction:</b> In the context of SARS-CoV-2 infection, it has been proposed that oxidative stress may contribute to the management of COVID-19 severity. The impact on the well-being of patients with COVID-19 using cysteine-providing supplements has not yet been evaluated and there is a need to understand the benefits and limitations they may offer.<br /> <b>Aim:</b> The aim of this study is to understand the experiences of improved well-being with cysteine-rich whey protein supplementation (Immunocal®) in patients with COVID-19.<br /> <b>Methods:</b> A qualitative study was conducted by conducting semi-structured interviews with four participants taking Immunocal® while they had COVID-19. Participants were randomly recruited through internet networking. Ethical approval was obtained from the University ethics committee. Participants were informed of the study objectives two days in advance and consent was obtained before interviews began. We used the 16-item “Use of Immunocal supplement for COVID-19” (USIC-19) questionnaire to inquire about COVID-19 behavior (time of illness, symptoms, and severity of illness) and the experience of using the supplement during illness. Confidentiality was maintained throughout this study.<br /> <b>Results:</b> All participants presented mild discomfort such as headache, weakness, and tiredness when they had COVID-19 impacting most of them emotionally. The use of Immunocal® produced a partial improvement in all patients as only two continued to experience fatigue. Immunocal® improved the mood (50%) and physical health of the participants. In addition, participants reported that the supplement was recommended and dosed primarily by a consultant and that they did not feel hesitant to use it because of previous experiences of friends and family. The daily dosage of half of the participants was two sachets and all felt the need to consume the supplement which resulted in daily use.<br /> <b>Conclusion:</b> Following the daily dosage indications of the consultants, the participants who have consumed Inmunocal® have presented a partial improvement of the symptoms related to COVID-19, however, they feel the need to consume the supplement daily to improve their quality of life.