Ashwagandha, a plant used in traditional Ayurvedic medicine, is increasingly marketed as a natural remedy for stress, sleep problems and other health concerns. Research suggests it may help some people manage stress and insomnia, but evidence for many other advertised benefits remains limited.
The plant, scientifically known as Withania somnifera, is also called Indian ginseng or winter cherry. It is an evergreen shrub found in parts of Asia, Africa and the Middle East.
Its roots and leaves contain compounds called withanolides, which have been studied for their potential biological effects. However, findings from laboratory research do not necessarily establish that a supplement is effective or safe for treating a medical condition.
The US National Center for Complementary and Integrative Health (NCCIH) says some preparations may help with stress and insomnia, although many clinical studies have involved small numbers of participants and different formulations. Evidence remains insufficient for several other conditions for which the supplement is promoted.
What research says about ashwagandha
Ashwagandha is commonly sold as a dietary supplement in capsules, powders and extracts. Its effects can vary depending on the plant material, preparation and amount used.
Researchers have investigated its potential effects on stress, sleep, blood sugar, cognitive function and reproductive health. The strength of the evidence differs considerably between these areas.
Stress and sleep
Stress management and insomnia are among the uses with the most encouraging evidence.
Some clinical trials suggest that particular ashwagandha preparations may reduce perceived stress and improve sleep quality. Researchers have also examined their effects on cortisol, a hormone involved in the body’s response to stress.
However, studies have used different doses and formulations, making it difficult to establish whether the results apply to all products sold as ashwagandha.
The evidence does not establish that the supplement can replace established treatment for persistent insomnia, anxiety disorders or other mental health conditions.
Blood sugar and diabetes
Researchers have investigated whether ashwagandha can influence blood glucose levels and insulin sensitivity.
Some studies have reported changes in blood sugar measurements, but the available evidence is not sufficient to establish the supplement as a treatment for diabetes or prediabetes.
People with diabetes should not replace prescribed medication with herbal supplements. Ashwagandha may also interact with medicines used to lower blood sugar, potentially complicating treatment.
Weight management
Claims that ashwagandha directly causes weight loss are not supported by strong clinical evidence.
Some research has examined whether reducing stress could influence eating patterns or other factors associated with weight management. That does not establish that the herb independently produces meaningful or sustained weight loss.
The supplement should not be regarded as a proven treatment for obesity.
Memory and cognitive function
Ashwagandha has been investigated for possible effects on memory, attention and other aspects of cognitive performance.
Some small studies have reported improvements in selected measures, but evidence remains insufficient to determine whether the supplement prevents dementia, treats Alzheimer’s disease or produces lasting improvements in cognitive function.
Findings from studies involving healthy volunteers cannot automatically be applied to people with diagnosed neurological conditions.
Depression and anxiety
Researchers have examined ashwagandha for its potential effects on stress-related symptoms and anxiety. Some studies suggest possible benefits, but the evidence for anxiety remains unclear.
Evidence supporting its use to treat major depression is also insufficient. It should not replace professional assessment or established treatment for depression.
Chronic pain and fibromyalgia
Ashwagandha has been investigated for its potential anti-inflammatory effects, but these findings do not establish that it treats chronic pain or fibromyalgia.
The supplied material describes a study involving ashwagandha, rifaximin and 5-HTP, but does not provide enough reliable bibliographic information to verify the study’s design or conclusions. Its findings therefore cannot be used to establish the effectiveness of ashwagandha for fibromyalgia.
People experiencing persistent pain should seek appropriate medical assessment rather than rely on an unproven supplement.
Inflammatory bowel disease
Inflammatory bowel disease (IBD) includes chronic conditions such as Crohn’s disease and ulcerative colitis, which cause inflammation in the digestive tract.
Although researchers have investigated herbal supplements and the gut microbiome, there is insufficient evidence to recommend ashwagandha as a treatment for IBD.
The supplied material also describes a study involving a probiotic identified as SCN9A, but the details are not adequately supported to establish what intervention was tested or what conclusions can be drawn.
People with IBD should continue to follow their prescribed treatment plan unless their healthcare professional advises otherwise.
Cancer treatment
Ashwagandha has been studied in laboratory experiments and preliminary research for possible effects on cancer-related processes. Such findings do not establish that it can cure cancer or improve survival.
The supplied material claims that all participants with advanced cancer who took ashwagandha in a 2013 study became cancer-free. This is a serious medical claim that cannot be substantiated from the information provided and should not be repeated as fact.
There is no adequate clinical evidence to support using ashwagandha as a cure for cancer or as a replacement for established cancer treatment. People undergoing cancer care should discuss supplements with their treatment team because of possible interactions.
Possible side effects of ashwagandha
Although the supplement is often marketed as natural, it can cause adverse effects.
According to the NCCIH and the US National Institutes of Health Office of Dietary Supplements, reported side effects include:
- Stomach discomfort
- Diarrhoea
- Nausea and vomiting
- Drowsiness
There have also been reports linking ashwagandha supplements to liver injury. Such cases appear to be uncommon, but some have involved clinically significant illness.
Anyone who develops yellowing of the skin or eyes, dark urine or other signs of possible liver problems while taking a supplement should seek prompt medical assessment.
Research on safety has mainly examined short-term use, generally for up to three months. The risks associated with longer-term use remain insufficiently understood.
Who should avoid it or seek medical advice?
The NCCIH advises against ashwagandha use during pregnancy and while breastfeeding. It also says the supplement is not recommended for people with thyroid or autoimmune disorders or those preparing for surgery.
Ashwagandha may interact with medicines for diabetes and high blood pressure, thyroid hormone treatments, sedatives, anticonvulsants and medicines that suppress immune activity.
People with liver disease should also exercise caution because of reports of supplement-associated liver injury. Those with hormone-sensitive prostate cancer should avoid it because it may affect testosterone levels.
Anyone taking prescribed medication or managing a chronic condition should consult a qualified healthcare professional before considering the supplement.
What consumers should know
Ashwagandha has a long history of traditional use, and modern research has identified possible benefits for stress and sleep. However, traditional use alone does not establish effectiveness, and evidence for many of the supplement’s wider health claims remains inadequate.
The available research does not justify presenting it as a proven treatment for diabetes, cancer, depression, fibromyalgia, inflammatory bowel disease or obesity.
Its safety also depends on individual circumstances, the preparation used and possible interactions with medicines. More high-quality research is needed to establish its long-term effects and determine which preparations, if any, offer reliable benefits for specific health conditions.
