Background: Patients with atopic dermatitis (AD) frequently use healthy lifestyle behaviors, although their benefits are unclear. This study's aim was to investigate the effectiveness of hypnotherapy, fasting with diet adjustments, and exercise in AD patients. Methods: In a four-armed randomized controlled monocenter open explorative clinical trial, adult patients with mild-to-moderate severe AD underwent, over 16 weeks, a five-session hypnotherapy group program (HTP), a five-session intermittent fasting with diet adjustment group program (IFDP), a five-session exercise group program (EP), or no study intervention (control) as add-on to topical corticosteroid use if required. Endpoints included subjectively perceived itching on a visual analogue scale (VAS, 0-100 mm); disease severity by SCORing Atopic Dermatitis (SCORAD); and adverse events (AEs). Endpoints were analyzed descriptively in the Full Analysis Set (FAS). Due to the coronavirus disease 2019 (COVID-19) pandemic, relevant changes to the study protocol included online in addition to "in-presence" group interventions, closing the study arm EP and premature trial termination before randomization of 120 intended patients. Results: During the COVID-19 pandemic, study recruitment was poor. The FAS included 20 patients (17 female) with 35.0 ± 12.1 (mean ± standard deviation [SD]) years of age. At baseline, mean ± SD for HTP (n = 6), IFDP (n = 4), EP (n = 1), and control (n = 9) were VAS itching 63.2 ± 18.0, 65.0 ± 13.9, 43.0 mm, 62.1 ± 17.3; SCORAD 43.0 ± 13.6, 47.0 ± 21.0, 60.3, 39.1 ± 15.6. After 16 weeks, endpoints were VAS itching 26.0 ± 16.4, 31.7 ± 9.9, 23.0 mm, 39.3 ± 27.0; SCORAD 24.1 ± 12.2, 29.1 ± 19.1, 49.1, 25.5 ± 14.4. No serious AEs related to the interventions were observed. Conclusion: Despite very small groups, study results indicated potential beneficial changes to baseline in perceived itching intensity, disease severity, and disease-specific quality of life for HTP and IFDP. Therefore, further clinical trials should be performed investigating the effectiveness and safety of all interventions. Clinical Trial Registration: January 31, 2020 German Clinical Trials Register (DRKS): DRKS00020557, Universal Trial Number (UTN): U1111-1247-1512.