Somatostatin affects how the body clock responds to evening light.

Somatostatin signaling through SSTR1 helped tune mouse circadian-clock sensitivity to evening light.

This animal study tested SST-deficient mice, SSTR1 knockout mice, pharmacologic SSTR1 inhibition, histology, and chronic SSTR1 agonist treatment under long photoperiod conditions.

The evidence is from mouse genetic and pharmacologic models, so it does not establish the same light-sensitivity mechanism in humans.