From the Guidelines
Milk thistle can potentially pass into breast milk, and nursing mothers should exercise caution when considering its use, consulting their healthcare provider first due to the limited research on its safety profile during lactation. When considering the use of milk thistle supplements while breastfeeding, it's essential to weigh the potential benefits against the risks, as the active compounds in milk thistle, such as silymarin and other flavonolignans, are likely to pass into breast milk in small amounts based on their molecular properties 1. Some key points to consider include:
- The safety profile of milk thistle for breastfeeding women is not well established, making it crucial to discuss alternative options with a healthcare provider that have better-established safety profiles during lactation.
- While milk thistle is generally considered safe for many adults, the potential effects on infants exposed to it through breast milk are not well documented, leading to a recommendation to avoid unnecessary supplements during breastfeeding unless the benefits clearly outweigh potential risks.
- Healthcare providers may recommend caution due to the lack of comprehensive studies on the transfer of milk thistle into breast milk and its impact on nursing infants, as seen in the context of patients with chronic HCV infection who frequently use herbal remedies like silymarin (milk thistle extract) 1. Given the information available, it is advisable for breastfeeding mothers to consult with their healthcare provider before starting any milk thistle supplementation to ensure they are making an informed decision that prioritizes both their health and the health of their infant.
From the Research
Milk Thistle and Breast Milk
- Milk thistle, also known as Silybum marianum, is a plant that has been used for medicinal purposes for over 2000 years 2.
- The active constituent of milk thistle, silymarin, has been shown to have various health benefits, including hepatoprotective, antioxidant, and anti-cancer effects 3, 2, 4.
- Regarding the use of milk thistle during lactation, studies suggest that it is safe to use during breastfeeding 3, 5.
- One study found that silymarin treatment during pregnancy and breastfeeding did not promote significant morpho-functional changes in the offspring in their initial development and adult behavior, indicating the safety of its use during gestation and lactation 5.
- Another study mentioned that milk thistle has been used as a galactogogue to increase breast milk production, but the efficacy and safety data are lacking 6.
Presence of Milk Thistle in Breast Milk
- There is no direct evidence in the provided studies that specifically addresses whether milk thistle or its active constituents are present in breast milk.
- However, the studies suggest that silymarin is safe to use during lactation, which implies that it may be transferred to breast milk, but the exact amount and effects are not specified 3, 5.