<p><i>Adiantum lunulatum</i> Burm.f. is a rich source of essential oils (EO) with various medicinal properties, including antimicrobial, anti-inflammatory, antioxidant, and wound healing potentials. The plant has also been suggested to exhibit anticancer and antiviral activities, although the efficacy and mechanism of action are very limited. This work is set out to first investigate the chemical constituents present in the <i>n</i>-hexane fraction (EO) obtained from a 50% aqueous-ethanol crude extract using GC-HRT-MS analytical techniques, and secondly to present an updated and categorized summary on the potential biological activities of the (EO) when compared to the crude ethanolic extract. Analysis shows 2,4-decadienal isomers and <i>n</i>-hexadecanoic acid are the most abundant chemical constituents in this fraction, with a total of 43.32% for the (E,E) isomers and 6.19% for the <i>n</i>-hexadecanoic acid, respectively. Antidiabetic, antioxidant, and cytotoxicity tests of the crude ethanolic extract (AEE) and <i>n</i>-hexane fraction (EO) revealed that AEE has far better bioactivity than the <i>n</i>-hexane fraction. Both extracts demonstrated lower activity against standard ascorbic acid for α-amylase and α-glucosidase. In addition, both extracts show moderate inhibitory effects on Caco-2 cells, a lower toxicity profile toward normal embryonic cells (Hek293-T), and significant efficacy against the HCT116 cells. The extracts also showed a non-toxicity property on HEK293-T cells in contrast to the positive control, doxorubicin.</p> Graphical abstract <p></p>