Ashwagandha (Withania somnifera), also known as winter cherry or Indian ginseng, is a plant recognized for its sleep-promoting properties. It also helps relieve stress, reduce anxiety, and improve athletic performance.
Despite its benefits, ashwagandha may not be for everyone. It may be unsafe for certain people, such as those with liver disease, thyroid problems, and prostate cancer.
Ashwagandha is generally safe and well-tolerated when used for a short time. However, some people may experience side effects such as:
- Digestive issues: Large doses of ashwagandha may cause stomach upset, nausea, and vomiting. This is likely because ashwagandha irritates the lining of your intestines.
- Drowsiness and sedation: Ashwagandha can make you feel sleepy and drowsy. As a result, you may feel more fatigued than normal. This effect may be worse if you take ashwagandha with anxiety medications like Valium and Xanax (benzodiazepines) or anti-seizure medicine.
- Headaches: Some people report experiencing headaches while taking ashwagandha. The exact reason why this happens is not yet known. However, taking higher doses or taking ashwagandha with other medications may increase this side effect.
Other, less common side effects you may experience when taking ashwagandha include:
- Cough
- Weight gain
- Nasal congestion
- Night cramps
- Blurred vision
Ashwagandha may have more serious side effects, such as:
- Liver injury: There have been reports of liver injury in people taking ashwagandha, usually appearing after about two to 12 weeks of use. However, in most cases, liver injury typically resolves within one to four months of discontinuing the ashwagandha supplement.
- Increased thyroid function: Studies have shown that ashwagandha can increase thyroid hormone levels. This may worsen symptoms in people living with hyperthyroidism (overactive thyroid).
- Increased testosterone levels: Ashwagandha can significantly increase testosterone levels. As a result, it can interfere with treatment for people with hormone-sensitive prostate cancer.
- Allergic reactions: Although rare, some people experience allergic reactions to ashwagandha. Symptoms include itching, difficulty breathing or swallowing, rash, or swelling. Consult your healthcare provider immediately if you notice any of these side effects.
The recommended daily dose of ashwagandha varies depending on its intended use and the part of the plant used (roots or leaves). For example, doses of 250-1,000 milligrams per day have been shown to reduce pain, while daily doses of 300-600 milligrams are recommended for anxiety.
In general, many clinical trials have used ashwagandha safely in doses of 225-1,000 milligrams daily for up to three months. There is currently no established upper limit for ashwagandha. However, adhering to doses that have been proven safe in studies may help reduce the toxic side effects associated with high doses of ashwagandha.
One study reported that some people who took doses of 450-1,350 milligrams of ashwagandha for about as long as one week up to four months experienced signs of liver injury. If you notice signs of liver problems, such as jaundice (yellowish discoloration of the skin or eyes), itching, nausea, constant fatigue, or stomachache, stop taking ashwagandha and consult your healthcare provider immediately.
Ashwagandha may not be suitable for everyone. Do not use ashwagandha supplements without first talking to your healthcare provider if you fall into one of these groups:
- People who are pregnant: Ashwagandha may cause spontaneous abortion (miscarriage) and should not be used by people who are pregnant. There are not enough studies to ensure its safety in breast milk, so people who are breastfeeding should avoid ashwaganda as well.
- People with prostate cancer: Ashwagandha may increase testosterone levels, which intensifies the progression of cancer. So, people with hormone-sensitive prostate cancer should avoid its use.
- People with an autoimmune disease: Ashwagandha can stimulate the immune system. This can worsen symptoms in people who have an overactive immune system, such as people with autoimmune diseases like lupus, multiple sclerosis, or rheumatoid arthritis.
- People with hyperthyroidism: As mentioned earlier, ashwagandha can worsen symptoms in people living with hyperthyroidism due to its ability to increase thyroid hormones.
- People undergoing surgery: Ashwagandha is not recommended for people who are about to have surgery because it could interfere with anesthesia or affect their blood sugar levels. It is advised to stop taking ashwagandha at least two weeks before surgery.
Interactions With Medications
Ashwagandha can interact with some prescription medications, either increasing or lowering their effects. Always talk to your doctor before using this herbal supplement if you are taking other medications. Some medicines ashwagandha may interact with include:
- Sedatives or anti-anxiety medicines: Valium (diazepam), Xanax (alprazolam)
- Thyroid hormones or antithyroid medicines: Synthroid (levothyroxine), Cytomel (liothyronine), methimazole
- Blood sugar-lowering medications: insulin, Glucophage (metformin), Glucotrol XL (glipizide)
- Immunosuppressants and organ transplant medications: Imuran (azathioprine), Prograf (tacrolimus), corticosteroids
- Blood pressure-lowering medicines: Norvasc (amlodipine), Cozaar (losartan)
Ashwagandha is generally tolerable. However, if you have mild side effects, try these tips:
- Stomach-related side effects: If you experience stomach issues, such as nausea, consider reducing your dose and taking ashwagandha with a meal that contains fats.
- Drowsiness: If ashwagandha makes you drowsy, consider taking it at night to avoid it interfering with your day-to-day activities. Reducing the dose may also help.
- Headaches: Starting with a low dose or lowering your dose may help reduce headaches associated with taking ashwagandha.
You can also minimize ashwagandha side effects by avoiding taking it with substances that heighten its effect, such as alcohol, sedatives, or medicines that make you sleepy.
If your symptoms don’t go away or get worse after lowering your dose, or if you experience an allergic reaction to ashwagandha, stop taking your supplements immediately and consult a healthcare provider.
