There are very few reasons a mother cannot breastfeed her infant if she desires. Whenever possible, breastfeeding is recommended by the American Academy of Pediatrics (AAP) as the preferred exclusive feeding method for the first six months of life and for at least the first year in combination with the introduction of solid foods.

However, smoking marijuana (or using any other illicit drug) is an absolute contraindication, meaning that no mother should ever breastfeed at the same time she is smoking marijuana. Marijuana is on the AAP’s list of “Drugs of Abuse Contraindicated During Breastfeeding.” The AAP Committee on Drugs has determined that the harmful effects of marijuana on the baby outweigh the enormous benefits of breastfeeding.

The active ingredient in marijuana, THC, is concentrated in breast milk, which means it can be passed on to the baby and later found in the infant’s urine and stool. In fact, a baby’s urine drug screen will be positive for 2-3 weeks after a baby drinks affected breast milk. Additionally, studies have shown that marijuana lingers in the mother’s body. THC is stored in body fat and is detectable in the urine for weeks after smoking, although this depends on the frequency of use, the mother’s metabolism, and how much of the drug is smoked. There is very little data on how long THC remains present in breast milk after smoking marijuana, so it’s best to avoid it completely.

Marijuana can cause long-lasting developmental effects in your baby’s growing brain. Studies have shown that babies who are exposed to marijuana through breast milk have decreased motor development at 1 year old. Furthermore, a mother who is under the influence of marijuana is likely impaired in her ability to care for her infant, putting the baby in even more danger. Beyond breastfeeding, infants can suffer negative effects by just inhaling the secondhand smoke, so babies should be kept away from anyone smoking the drug.


  • Breastfeeding is the preferred feeding method, according to the American Academy of Pediatrics (AAP).
  • The AAP recommends that breastfeeding mothers completely avoid smoking marijuana.
  • The active ingredient in marijuana, THC, is transferred through a mother’s breast milk to her baby and can be detected even three weeks later in baby’s urine.
  • Marijuana use among breastfeeding mothers is associated with lasting developmental problems in growing babies.

Last reviewed by Sara Connolly, MD. Review Date: March 2020


  1. American Academy of Pediatrics. Marijuana Use During Pregnancy and Breastfeeding: Implications for Neonatal and Childhood Outcomes.
  2. Centers for Disease Control and Prevention. Is it safe for mothers who use marijuana to breastfeed?


  1. This isn’t specific at all. There is no data backing up the possible harm. This is a very poor artical that left me with more questions and cleared nothing for me. Back yourselves up with statistics and facts.

    1. In some cases, including this one, it is very difficult to perform formal studies in order to generate data. No one wants to give a group of babies THC then follow them over the years to see if it negatively impacts their development or IQ. So the caution comes from understanding THC’s affects on the adult and adolescent brain, where we do have data. I believe the AAP’s stance here reflects a better safe than sorry approach.


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