This study aims to investigate the impact of frilufts-therapy (Nordic inspired therapeutic interventions in nature) on adolescents' mental health through a systematic literature review following PRISMA 2020 guidelines. Inclusion criteria encompassed peer-reviewed intervention studies in English, Danish, or Norwegian, quantitatively evaluated with pre- and post-measurements on outcomes pertaining to salutogenesis. Papers published between 2010--2021 were selected from PubMed and PsycInfo in November 2021. Risk of bias was assessed using Cochrane RoB 2, ROBINS-I, and NIH tools synthesized into a six-domain assessment. Ten papers evaluating 12 studies (1711 adolescents) were selected. Meta-analysis of effect estimates on controlled studies (7) revealed a medium to large effect (ES = 0.70; CI = 0.41-0.98) favouring frilufts-therapy. Meta-analysis without control (11 studies) showed a medium effect (ES = 0.52; CI = 0.34-0.70) favouring post-test measurements. This support evidence that frilufts-therapy can improve the mental health of adolescents, but caution is advised due to potential study limitations, necessitating further research.