California Poppy and Breastfeeding
Before using California poppy, breastfeeding women should talk to their healthcare provider. It is not known if California poppy passes through breast milk or if it is safe for use while breastfeeding. Until more information is available on the safety of taking California poppy while breastfeeding, women are typically advised to avoid this herbal supplement while nursing a child.
It is not known if California poppy supplements are safe for use in women who are breastfeeding. California poppy is an herbal remedy often used to treat anxiety, insomnia, or depression, although it is sometimes claimed to be useful for other conditions as well. It is also used recreationally for its mild euphoric and sedative effects. Until more information is available, it is probably a good idea to avoid California poppy while breastfeeding.
It is not known if any of the compounds in California poppy pass through breast milk, and it is not known if California poppy is safe for breastfeeding women or their infants. Although it is a "natural" product, this does not necessarily mean that it is safe for use while breastfeeding. Many women try to avoid medications while breastfeeding and turn to herbal remedies as an alternative, assuming that "natural" automatically means "safe." However, natural products can be quite toxic. For instance, many poisons and toxins are natural products.
It's important to note that California poppy has not been shown to be effective for any use (see Does California Poppy Work?). It just does not make sense to use an herbal supplement for which there is no information available about its safety during breastfeeding, especially when there is no evidence that the herb really works for anything.