<p>The bi-directional communication of the brain-body axis, including afferent (e.g., interoception) and efferent signal transmission (e.g., stress), is critical for understanding stress-related disorders. Transcranial magnetic stimulation using theta burst stimulation (TBS) protocols can be used to inhibit or to enhance activity in the interoceptive brain network (IBN), which may also affect efferent signal transmission, such as stress. This preliminary study aimed at investigating the effects of different TBS protocols that modulate IBN activity on physiological stress responses, as well as of stress responses on interoceptive accuracy (IAc) and heartbeat-evoked potentials (HEPs), which are two measures of cardiac interoception. Twenty-one participants were randomly assigned to either an inhibiting continuous protocol (cTBS), facilitating intermittent stimulation (iTBS), or an ineffective intermediate stimulation (imTBS) protocol targeting the right supramarginal gyrus (rSMG). Participants underwent both a stress (Socially Evaluated Cold Pressor Task) and a control condition. Stress significantly increased systolic/diastolic blood pressure (SBP/DBP) and cortisol levels. Stress did not affect IAc, but increased HEP amplitudes 455–595 ms after the R-wave, regardless of the stimulation protocol. Moreover, we found a trend towards an increase of negativity of HEPs 860–1000 ms, after the R-wave in the cTBS. No further effects of the stimulation condition on stress responses or measures of cardiac interoception were observed. This offers preliminary evidence that IBN stimulation or inhibition does not affect stress responsiveness. Acute stress affects interoceptive attention (reflected by HEPs), but not IAc. Hence, acute stress may enhance attentional resources focused on interoceptive sensations, potentially at the cost of resources for processing exteroceptive sensory information.</p>