What health professionals should do
Background
W. somnifera is a permitted herbal ingredient in listed medicines in Australia. Its use in listed medicines is not subject to specific restrictions regarding dose, concentration, or type of preparation. However, a pregnancy warning statement – external site is required on the label of the medicine for certain preparations of the herb.
Herbal extracts of W. somnifera contain a variety of bioactive constituents, including withanolides such as Withaferin A, Withanolide A, and Withanone, each with various reported pharmacological activities. The presence and concentration of these withanolides can vary depending on whether the leaf or root part has been used. Most listed medicines in Australia use concentrated extracts derived from the root, while the leaf component is less commonly used. Additionally, the extraction method and extraction ratio influence the composition of the final product.
We received an adverse event report in 2021 of a serious liver injury associated with a listed medicine that contained W. somnifera. Following this, we initiated a safety review to investigate the relationship between W. somnifera and liver injury.
We issued a safety alert in 2024 highlighting that medicines and herbal supplements containing the herb W. somnifera may be associated with liver injury in very rare cases. This alert was prompted by evidence in the scientific literature and an increase in reported adverse events. Most of the reported liver injury cases resolved following discontinuation of the product, although some required medical treatment and 4 cases required hospitalisation. The safety alert also warned of sudden and potentially severe gastrointestinal symptoms in some people.
In 2023, researchers in India reviewed hospital records for herb-induced liver injury, reporting 8 cases of liver injury – external site associated with single-ingredient W. somnifera preparations. The patients had consumed herbal preparations in various dosage forms, including powdered root, syrups, tablets, and herbal teas. The case series included patients with pre-existing liver disease and included the 3 patients with fatal outcomes, mentioned in the Summary section above.
The Netherlands Pharmacovigilance Centre published alerts in September 2023 – external site and July 2025 – external site reporting a total of 12 liver injury cases up to June 2025. Time to onset of liver injury varied from 6 weeks to 22 months. At the time of the alert, most patients had recovered after discontinuing the product.
Additionally, a 2024 report – external site from the National Institute for Public Health and the Environment in the Netherlands also identified that food supplements containing W. somnifera, currently available on the Dutch market, may lead to adverse effects – including liver injury – in sensitive individuals.
In 2024 the Ministry of Ayush – external site in India published an updated safety dossier 2.0 on W. somnifera root which found no evidence of intrinsic liver toxicity and commented that reported cases of liver injury may be due to other causes, or at most, rarely may be idiosyncratic reactions that need more investigation. The dossier concluded that W. somnifera root extract is safe for human consumption.
The use of W. somnifera leaves was recently banned in India – external site, while the use of W. somnifera roots remains permitted, subject to prescribed limits. The TGA is considering available evidence on the role of different plant parts in liver injury and gastrointestinal adverse effects.
Adverse events reported to us
Since the publication of the TGA’s 2024 safety advisory, we have received a further 4 adverse event reports with enough information to suggest a possible liver injury that may have been caused by medicines containing W. somnifera. However, in 2 cases, there were other ingredients linked to liver injury that may have contributed to the reported reactions. All resolved on discontinuation of the suspected medicine and none reported that hospitalisation was needed.
This brings the total number of possible liver injury cases reported to us to 11. In 6 of these cases there were no other ingredients considered likely to have contributed to the liver injury. In 4 of these 6 cases, the suspected W. somnifera-containing medicines were listed on the Australian Register of Therapeutic Goods, with hospitalisation needed in 2 of these 4 cases.
In addition to cases reported in Australia, we are aware of possible liver injury cases associated with single ingredient W. somnifera medicines received by regulators in other countries, as reported to the World Health Organization Programme for International Drug Monitoring – external site.
The available evidence indicates that while the risk appears to be very rare, there is a potential for liver injury associated with the use of this herbal ingredient. We will continue to assess emerging evidence and determine on the weight of the evidence whether any regulatory action is necessary.
Adverse event reporting for herbal medicines
Our ability to monitor for health and safety issues with herbal medicines depends, in part, on health professionals reporting adverse events. Just under half (5 out of 11) of the possible liver injury adverse event reports involving W. somnifera medicines received by us were submitted by health professionals.
Reports submitted by health professionals play a critical role in:
- identifying potential health and safety risks associated with herbal medicines for the Australian public
- informing future regulatory actions, such as the inclusion of health warnings on product labels, to help mitigate identified risks to consumers.
We strongly encourage health professionals to report any suspected adverse events associated with herbal medicines. Timely and accurate reporting enhances our ability to detect emerging safety signals and take appropriate regulatory action to protect public health.
