The constituents of hollyhock (Alcea rosea, Althaea rosea) leaf have not been well described, but it is believed to contain flavonoids, phenolic acids, and tannins. Few studies on hollyhock related to breastfeeding exist, but one moderately well done study found that a compress of hollyhock leaf sped resolution of engorgement during breastfeeding.
Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products. More detailed information about dietary supplements is available elsewhere on the LactMed Web site.