You should not dye your hair during breastfeeding. Hair dye is a chemical reagent and contains some toxic chemicals. After dyeing, some of the toxic substances will be absorbed by the scalp and enter the breast milk through blood circulation, thus affecting the quality of milk. At this time, the baby’s liver and kidney function is not yet perfect, easy to cause the accumulation of chemical reagents, to the detriment of the baby’s health and development. Specific hazards are as follows: 1, easy to allergic: lactating women have lower resistance, some women’s body functions will change after childbirth, pre-pregnancy hair dyeing does not mean postpartum allergies, postpartum hair dyeing may appear urticaria, dermatitis, eczema contact dermatitis and other conditions, the initial stage may be manifested as itching, redness and other symptoms. The baby may also appear allergic symptoms by sucking breast milk; 2, easy lead poisoning: poor quality hair dye contains a lot of lead, the baby by touching the mother’s hair and then sucking fingers, take snacks to eat will ingest the lead, which may lead to the baby’s loss of appetite, abdominal pain, diarrhea and other symptoms of lead poisoning; 3, aggravate the degree of hair loss: due to the influence of hormones, some women breastfeeding hair loss is very serious. At this time, perm may damage the underlying tissue of the hair, which will accelerate the speed and scope of hair loss. To sum up, it is best for women not to dye their hair while breastfeeding to avoid increasing the potential health risk factors for themselves and their babies.