Tramadol and its metabolite, O-desmethyltramadol (M1), are present in human milk. There is no information on the results from the drug on the breastfed toddler or the results with the drug on milk manufacturing. The M1 metabolite is more strong than tramadol in mu opioid receptor binding [see Scientific Pharmacology https://anthonyp244jcr7.oblogation.com/profile