Abstract Background: There are little data on the risk to a breastfeeding infant after facial botulinum toxin injections to the mother. Objective: To detect the presence of botulinum toxin in breast milk from lactating subjects treated with facial botulinum toxin injections, as measured by enzyme-linked immunosorbent assay (ELISA). Methods: For this pilot study, lactating women were injected with standardized facial botulinum toxin type A (BTXA) (range 40-92 U). Collected breast milk samples over 5 days were analyzed for the presence of botulinum toxin. Exclusion criteria included (1) lactating women still using their breast milk for their infant, (2) muscular disorders, (3) any medication that could interfere with neuromuscular function, (4) uncontrolled systemic disease, (5) pregnant, and (6) neuromodulator injection in the past 90 days. Results: Four lactating women were recruited. Eight samples had no BTXA detected, whereas 8 of the 16 total had detectible amounts, which were well below the reported lethal oral dose for an infant. Conclusion: Although the exclusion of lactating women from receiving cosmetic botulinum toxin injections is out of an abundance of caution to the theoretical risk to the infant, this study helps support the notion that facial botulinum toxin injections do not warrant an interruption in breastfeeding. Further studies with larger sample sizes are needed.