Abstract: The present study was conducted for the evaluation of Interleukin (IL)-1b levels in human gingival crevicular fluid (GCF), intensity of pain, and the amount of tooth movement measured during canine retraction using different magnitudes of continuous orthodontic force. A statistically significant no. of subjects were included for the study (n=16, 6 male subjects and 10 female subjects). The age ranged from 18 to 24 years and all were diagnosed with Class I bimaxillary protrusion. They underwent first premolar extractions prior to participating in the study. The maxillary cuspids were then retracted using a continuous force of either 50 g or 150 g. This was executed using nickel–titanium coil springs on segmented arch wires. The opposite counterpart i.e. mandibular cuspid was used as control. Gingival crevicular fluid was then drawn from the distal aspect of each tooth at defined time intervals. This was followed by the assessment of IL-1b concentrations, pain intensity, using the visual analogue scale (VAS), and the amount of tooth movement. ANOVA test, Friedman test and paired t-tests were used for comparisons of IL-1b in GCF, the plaque and gingival indices, and the efficiency of tooth movement on pain perception, respectively. The 150 g group showed the highest level of IL-1b concentration at 24hrs from baseline and at 2 with significant differences compared with the control group (P < 0.05). The mean VAS score of pain intensity from the 150 g force was significantly greater than from the 50 g force at 24 hours (P < 0.01). However, no significant difference in the amount of tooth movement was found between these two different magnitudes of continuous force at 2 months. A 50 g force could effectively induce tooth movement similar to 150 g with less pain and less inflammation.