A four-week course of chronic intranasal oxytocin administration in children with autism increased salivary oxytocin levels 24 hours after the last dose but not at a four-week follow-up. Oxytocin also reduced DNA methylation of the oxytocin receptor gene (OXTR), suggesting increased receptor expression. Higher oxytocin levels were linked to reduced OXTR methylation and improved feelings of secure attachment. These findings indicate that chronic oxytocin administration stimulated the endogenous oxytocinergic system in children with autism. The study, a randomized, placebo-controlled trial, found that oxytocin administration led to increased salivary oxytocin levels and decreased OXTR methylation compared to placebo. Oxytocin levels were significantly associated with improved clinical outcomes, including secure attachment and reduced social difficulties. However, these effects were not sustained at the four-week follow-up. The study highlights the potential of chronic oxytocin administration to enhance endogenous oxytocinergic function, though further research is needed to determine optimal dosing and long-term effects. The results suggest that combining oxytocin with social interventions may enhance therapeutic outcomes. The study also underscores the importance of epigenetic changes in understanding the biological mechanisms underlying oxytocin's effects in autism.A four-week course of chronic intranasal oxytocin administration in children with autism increased salivary oxytocin levels 24 hours after the last dose but not at a four-week follow-up. Oxytocin also reduced DNA methylation of the oxytocin receptor gene (OXTR), suggesting increased receptor expression. Higher oxytocin levels were linked to reduced OXTR methylation and improved feelings of secure attachment. These findings indicate that chronic oxytocin administration stimulated the endogenous oxytocinergic system in children with autism. The study, a randomized, placebo-controlled trial, found that oxytocin administration led to increased salivary oxytocin levels and decreased OXTR methylation compared to placebo. Oxytocin levels were significantly associated with improved clinical outcomes, including secure attachment and reduced social difficulties. However, these effects were not sustained at the four-week follow-up. The study highlights the potential of chronic oxytocin administration to enhance endogenous oxytocinergic function, though further research is needed to determine optimal dosing and long-term effects. The results suggest that combining oxytocin with social interventions may enhance therapeutic outcomes. The study also underscores the importance of epigenetic changes in understanding the biological mechanisms underlying oxytocin's effects in autism.