Ashwagandha (Withania somnifera) has become one of the fastest-growing categories on UK pharmacy shelves. It is marketed as an "adaptogen" for stress, sleep and testosterone, and customers now arrive asking for it by name. The evidence base is genuinely more substantive than for most adaptogens — but a hepatotoxicity signal has been flagged by regulators in Europe and Australia, and pharmacy teams need to handle this carefully.
What "adaptogen" actually means
The term "adaptogen" was coined in the 1940s Soviet military research programme to describe compounds that theoretically normalise physiological function under stress. It has no equivalent recognition in UK or European medicines regulation. EFSA has not authorised any health claim using the word "adaptogen" for any botanical.
The main adaptogens on UK pharmacy shelves are:
| Herb | Principal claim | Evidence strength |
|---|---|---|
| Ashwagandha (Withania somnifera) | Stress, sleep, anxiety | Moderate in short trials |
| Rhodiola (Rhodiola rosea) | Fatigue, stress | Mixed, small trials |
| Schisandra (Schisandra chinensis) | Mental performance | Very limited |
| Panax ginseng | Fatigue, cognition | Mixed, heterogenous trials |
| Cordyceps | Energy, exercise | Preliminary |
Of these, ashwagandha is the one where a pharmacy conversation is now an almost daily occurrence in many stores.
What the ashwagandha evidence shows
A 2023 systematic review of 12 randomised controlled trials (approximately 1,000 participants total) reported reductions in perceived stress, Hamilton Anxiety Scale scores and morning cortisol with ashwagandha extracts, typically at 300–600 mg of a standardised root extract for 8 weeks. Effect sizes on stress measures are moderate; sleep outcomes are smaller and less consistent.
Trials on testosterone, muscle strength and cognitive function exist but are smaller, often industry-sponsored and should be interpreted cautiously.
The size of the effect is real but not dramatic. Customers expecting the supplement to replace treatment for anxiety or depression will be disappointed — and should be. NICE CKS on stress advises on graded self-help, talking therapies and lifestyle; ashwagandha is not mentioned in the guideline.
The hepatotoxicity signal
This is the piece that has changed pharmacy counselling over the last two years.
Denmark's food authority DTU published a risk assessment in 2023 recommending against unrestricted sale of ashwagandha extracts, citing concerns about endocrine and liver effects. Australia's Therapeutic Goods Administration issued a safety advisory in 2023, updated in 2024, noting reports of liver injury associated with ashwagandha use and advising consumers to stop and seek medical advice if they develop jaundice, dark urine, nausea or abdominal pain.
The US National Institutes of Health LiverTox database has catalogued more than 20 published case reports of ashwagandha-associated liver injury, generally a cholestatic or mixed pattern, typically appearing 2–12 weeks after starting the supplement, and usually resolving after withdrawal. A 2023 case series in the Journal of Clinical and Experimental Hepatology added further reports from India.
The European Food Safety Authority's 2024 opinion concluded that safety of ashwagandha root and leaf preparations could not be fully established at intakes above a defined limit; it recommended further assessment. The Medicines and Healthcare products Regulatory Agency has not issued a UK-specific advisory at time of writing, but pharmacy teams should treat the signal as real.
What to say at the counter
A practical conversation covers four points.
- Set expectation. Evidence supports modest reductions in perceived stress in short trials. It is not a substitute for treatment of clinical anxiety or depression.
- Screen liver risk. Ask about existing liver disease, hepatitis B or C, heavy alcohol use or other hepatotoxic medicines (methotrexate, isoniazid, high-dose paracetamol, some statins). Advise against use where any of these apply.
- Counsel for warning symptoms. Jaundice, dark urine, pale stools, right upper quadrant pain, persistent nausea or unexplained fatigue. Stop and seek medical advice if these develop at any point, even months into use.
- Time-limit. Evidence is strongest over 8 weeks. Continuous use beyond 3 months without review is not supported and increases the window for a hepatotoxic reaction.
Specific exclusions
Ashwagandha should not be supplied to:
- Pregnant women — traditional use includes emmenagogue and abortifacient properties, and safety data in pregnancy are inadequate
- Breastfeeding mothers — insufficient data
- Customers with known autoimmune thyroid disease — may increase thyroxine levels
- Customers on thyroid hormone replacement without prescriber review
- Customers on immunosuppressants
- Customers on sedatives, including benzodiazepines and gabapentinoids, where additive sedation is possible
Other adaptogens: a shorter note
Rhodiola has fewer liver safety signals but a smaller evidence base. Panax ginseng can raise blood pressure and interact with warfarin; ask about both. Schisandra has theoretical CYP3A4 interactions. In every case, the same four-point framework — expectation, screening, warning symptoms, time-limit — applies.
Where this fits in UK pharmacy
Stress, anxiety and sleep remain among the most common self-care consultations in community pharmacy. PharmSee's pharmacy directory lists the contractor network customers rely on for this kind of evidence-based counselling, and our clinical pharmacy jobs listings reflect growing demand for pharmacists confident in supplement safety alongside medicines.
Caveats
This article summarises TGA, DTU, EFSA and LiverTox positions as of April 2026. The MHRA has not issued a UK-specific advisory at time of writing. Signals may strengthen. Always check the latest MHRA Drug Safety Update and the Yellow Card reporting scheme if a suspected adverse reaction occurs.