The robustness of a given physiological effector can be assessed by exploring the complexity profile of the biological signals it generates. The complexity of a signal is typically assessed as “entropy”, a general measure of disorganization. Higher complexity level reflects a higher robustness of the respective physiological effector, i.e., a higher adaptation capability to changing internal and external conditions. Recent publications have reported that physiological signals from subjects in pathological and prepathological states show lower entropy than in healthy subjects. On an experimental level, provocation maneuvers (e.g. postural changes, limb occlusion, drug administration, etc.) that challenge certain physiological effectors are also able to highlight their robustness, even in healthy subjects. Our objective was to assess the robustness of the physiological effectors of skin perfusion during a classic maneuver to evoke the venoarteriolar reflex (VAR). Fifteen healthy subjects (22.4 ± 5.2 y.o.) participated in this study after giving informed consent. After acclimatization, subjects performed a protocol to evoke VAR on the upper limb while sitting upright – 7 min resting with both arms at heart level (phase I), 5 min with one random arm (i.e., test limb) placed 40 cm below heart level (VAR, phase II) and 7 min recovery in the initial position (phase III). Skin blood flow was assessed in the index finger of both limbs with photoplethysmography (PPG). Raw PPG signals were then decomposed into their respective spectral components (cardiac, respiratory, myogenic, sympathetic, endothelial NO-dependent and endothelial NO-independent) with the wavelet transform. Finally, the complexity index of the raw PPG signal and of its components was calculated using the multiscale entropy analysis (MSE) algorithm. The Wilcoxon signed rank test was used to compare skin blood flow and complexity index between the different phases of the protocol (p<0.05). As expected, VAR induced a significant bilateral decrease in skin blood flow, more pronounced in the test limb. Similarly, during VAR the complexity index of the raw PPG signals and their components decreased significantly, again with higher magnitude in the test limb. These results suggest that a decrease in the competence of skin perfusion regulation effectors might be present during VAR, likely related to the magnitude of skin perfusion decrease.