Cold laser has considerable potential curative outcomes. This study desires to assess the relative efficacy of using soft laser as an additive therapy in rheumatoid arthritis by assaying the absorption spectra, studying the thermodynamic parameters of hemoglobin (Hb), plasma malonyldialdehyde (MDA), as well as erythrocyte osmotic fragility. Experiments were performed on 70 subjects with age group 50 ± 5 years. They were divided into three groups. The first group (G1) represents 20 normal adults as a control group. The second group (G2) represents 25 patients treated with non-steroid anti-inflammatory drugs (NSAIDs). The third group (G3) represents 25 patients treated with NSAIDs and undergo to cold laser generated from the mid-infrared laser medical device. RA patients susceptible to LLLT on three days a week for four weeks (i.e. 12 sessions per patient). The study revealed a significant improvement in the heme-heme interaction, exhibiting the stabilization of oxyhemoglobin induced by dual treatment in the third group. It has enhanced the dynamic motion of Hb as a folding process, which increases oxygen utilization. The results also showed a significant reduction in plasma malondialdehyde (MDA) besides lowering the average elevated osmotic fragility and a decrease in the high rate of hemolysis. In conclusion, by using a cold laser as a complementary therapy, there is a significant enhancement in the connection between hemoglobin synthesis and function.