Is there a boxed warning on black cohosh?

October 10, 2025 •

3 min read

Globally, there have been over 83 reported cases of liver damage associated with black cohosh use. So, is there a boxed warning on black cohosh? In the United States, the FDA does not require a boxed warning for this herbal supplement.

Quick Summary

Black cohosh does not have an FDA-mandated boxed warning in the U.S.. However, concerns about liver toxicity have led other countries and the U.S. Pharmacopeia to recommend cautionary labels.

Key Points

No U.S. Boxed Warning: The FDA does not require a boxed warning for black cohosh in the United States because it is regulated as a dietary supplement, not a drug.
Liver Damage Concern: Despite no FDA warning, there are reports linking black cohosh to liver damage, leading other countries and the U.S. Pharmacopeia to recommend cautionary labels.
Inconsistent Efficacy: It is primarily used for menopausal symptoms like hot flashes, but clinical evidence for its effectiveness is mixed and inconsistent.
Potential Drug Interactions: Black cohosh may interact with medications that affect the liver (like statins), and chemotherapy drugs like cisplatin.
Unregulated Market: As a supplement, black cohosh products are not standardized, and their purity and potency can vary, with some products potentially contaminated or mislabeled.
Consult a Professional: Due to potential risks and inconsistent benefits, it's crucial to consult a healthcare provider before using black cohosh.

Is there a boxed warning on black cohosh in the United States?

No, the U.S. Food and Drug Administration (FDA) does not require a boxed warning on black cohosh supplements. As an herbal supplement, black cohosh is not regulated by the FDA in the same way as prescription drugs. This means there are no standardized manufacturing requirements, and the purity and strength of these products can vary.

What is a Boxed Warning?

A boxed warning, also known as a "black box warning," is the strictest warning the FDA can place on a drug's label. It highlights serious or life-threatening risks associated with prescription drugs. Since black cohosh is a supplement, it does not fall under this specific FDA labeling requirement in the U.S..

Global Warnings and Recommendations

Despite the absence of an FDA boxed warning, other health organizations have issued advisories due to concerns about liver damage (hepatotoxicity).

U.S. Pharmacopeia (USP): Recommended cautionary labeling for black cohosh products regarding liver disorders.
Australia: Requires a warning label stating black cohosh "may harm the liver in some individuals".
European Medicines Agency (EMEA): Advised discontinuation if signs of liver injury appear.

The potential link between black cohosh and liver damage is debated, with some suggesting contamination or mislabeling may be factors rather than inherent toxicity.

Pharmacology and Uses of Black Cohosh

Black cohosh (Actaea racemosa) is a North American plant whose root and rhizome are used in supplements.

Mechanism of Action

The exact mechanism is not fully understood. While initially thought to have estrogen-like effects, recent studies suggest it may act on serotonin pathways or as a Selective Estrogen Receptor Modulator (SERM). It may also possess anti-inflammatory and antioxidant properties.

Common Uses

Black cohosh is primarily used for menopausal symptoms, particularly hot flashes. However, studies on its effectiveness have yielded mixed results, with some showing benefit and others finding no significant difference compared to a placebo.

Risks, Side Effects, and Drug Interactions

Black cohosh is generally considered safe for short-term use (up to one year) but is associated with potential risks.

Common Side Effects

Gastrointestinal upset
Headache
Rash
Vaginal spotting or bleeding

Serious Risk: Liver Damage Though rare, liver damage is the most significant concern. Symptoms include fatigue, nausea, dark urine, and jaundice. Individuals with liver disease should avoid it.

Drug Interactions Black cohosh may interact with:

Hepatotoxic Drugs: Increased risk of liver damage when taken with other liver-harming medications.
Cisplatin: May decrease the effectiveness of this chemotherapy drug.
Medications Metabolized by the Liver: Could alter the metabolism of certain drugs.


Treatment	Mechanism	Efficacy for Hot Flashes (Evidence)	Key Risks
Black Cohosh	Unclear; serotonin pathways or SERM possible	Inconsistent results	Rare liver damage, GI upset, headaches
Hormone Therapy (HRT)	Replaces estrogen	Generally effective	Increased risk of stroke, heart disease, breast cancer
SSRIs/SNRIs	Affect serotonin levels	Effective in up to 65% of women	Nausea, dizziness, sexual side effects

Conclusion

While the U.S. FDA does not require a boxed warning for black cohosh, the potential for liver toxicity is a concern highlighted by other health agencies. Evidence for its effectiveness in treating menopausal symptoms is mixed, and it may interact with other medications. Due to the lack of regulation for supplements, product quality can be inconsistent. Consulting a healthcare professional before using black cohosh is recommended, especially for individuals with liver conditions or those taking other medications.

For more information from a governmental health authority, you can visit the National Institutes of Health Fact Sheet on Black Cohosh.

Frequently Asked Questions

No, the FDA does not approve or regulate black cohosh supplements for safety, potency, or medical use in the way it does for prescription medications.

The primary safety concern is the risk of liver damage (hepatotoxicity), although it is considered rare. More than 50 instances of clinically apparent liver injury have been linked to products labeled as black cohosh.

Yes. While not required in the U.S., Australia mandates a label warning that black cohosh may harm the liver. The U.S. Pharmacopeia also recommends a cautionary statement about liver trouble.

Common, mild side effects can include stomach upset, headache, rash, cramping, and a feeling of heaviness.

You should be cautious. Black cohosh may interact with drugs that are also metabolized by the liver, such as atorvastatin (Lipitor), and may decrease the effectiveness of drugs like cisplatin. Always consult your doctor before combining it with other medications.

The evidence is inconsistent. Some studies show it can reduce hot flashes and other symptoms, while other high-quality studies and reviews have found it to be no more effective than a placebo.

Studies suggest that black cohosh is possibly safe when taken for up to one year. Use beyond six months should be done under the guidance of a healthcare professional.