The proposed labeling requirements relate to adverse events reports relating to liver damage that emerged followed a review the international organization conducted.
While USP has indicated the causality between these ingredients and the condition is very minimal, it is issuing the announcement as a preventative measure.
"There has been an increase in the number of liver damage case reports," Gabriel Giancaspro, USP director of dietary supplements told NutraIngredients-USA.
USP spent more than one year reviewing the case reports associating the intake of these ingredients to liver damage.
Of the 155 adverse events reports it reviewed on black cohosh, 30 showed a "possible" causality for liver damage.
As for green tea extract, USP reviewed over 250 case reports - finding 27 instances of "possible" causality and seven cases of "probable" causality.
However, the organization did find "concerning variables" surrounding these so-called probable links between the condition and green tea extract, USP's scientific liaison on dietary supplements, Dandapantula Sarma, told NutraIngredients-USA. Variables that affect such causality between the ingredients relate to factors such as an individual history of liver disease, or the manner in which it is ingested.
As such, the caution label USP is proposing for green tea extract stipulates the supplement should be taken with a meal.
The third party certifier is inviting comments and feedback from manufacturers for a 60-day period after publication in September.
The label requirement will then be made official by the organization.
The proposed cautionary statement applying to dietary supplements with green tea extracts will read: Caution: Must take with a meal.
In rare cases extracts from green tea have been reported to adversely affect the liver.
Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice.
The proposed label statement required for black cohosh will read: Caution: In rare cases black cohosh has been reported to affect the liver.
Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice.
Giancaspro underscored that because the liver damage cases in question have been rare, the statements are cautions and not in fact warnings.
As such, USP is not discouraging the consumption or marketing of these ingredients and will continue to issue monographs on them.
"It's okay to develop a monograph," said Giancaspro.
"As long as there's a statement asking for a label claim in the monograph."
USP already has a published monograph for black cohosh, and a monograph for green tea extract in the works.