ACT and polyvagal theory are natural companions. ACT gives us a values-driven map, while polyvagal theory reminds us that our nervous-system state shapes what is actually possible in a given moment.
When clients are stuck in fight, flight or shutdown, defusion exercises and values work can feel impossible. The doorway in is regulation — co-regulation with the therapist first, then internal regulation.
In practice, this means starting many sessions with a brief regulating ritual (orienting, slow exhales, grounding), and explicitly naming the state shifts that happen during the work.
Once safety is online, ACT processes land more fully. The acceptance step lands differently when the body believes it is safe to feel.