Ashwagandha (Withania somnifera), also known as Indian ginseng or winter cherry, is an evergreen shrub used for centuries in Ayurvedic medicine [1.6.2, 1.3.3]. As an adaptogen, it is believed to help the body resist physical and mental stress [1.8.4]. While it offers potential benefits for stress, anxiety, and sleep, it also contains active compounds that can interact with various medications [1.2.4]. Taking it without understanding these interactions can lead to unintended and potentially harmful side effects. It's crucial to consult a healthcare provider before adding ashwagandha to your regimen, especially if you take any prescription drugs [1.2.2].
Medications for Sedation (CNS Depressants)
The botanical name for ashwagandha, Withania somnifera, translates to “sleep-inducer,” highlighting its natural sedative properties [1.2.4]. When combined with other medications that depress the central nervous system (CNS), this effect can become dangerously amplified, leading to excessive drowsiness, dizziness, and slowed breathing [1.4.3, 1.4.5]. Avoid driving or operating heavy machinery if you combine ashwagandha with any sedative [1.2.2].
Key medications in this category include:
- Benzodiazepines: Used for anxiety and sleep, examples include alprazolam (Xanax®), clonazepam (Klonopin®), and diazepam (Valium®) [1.4.1, 1.4.3].
- Barbiturates: Such as phenobarbital, used for seizure control and sedation [1.4.1].
- Sleep Medications: Like zolpidem (Ambien®) and eszopiclone (Lunesta®) [1.2.5, 1.4.1].
- Opioid Pain Relievers: Such as oxycodone (Roxicodone®), which also have sedative effects [1.2.4].
Immunosuppressants
Immunosuppressant drugs are prescribed to dampen the immune system's activity, which is crucial for individuals with autoimmune diseases or those who have received an organ transplant [1.5.3]. Ashwagandha has been shown to have the opposite effect—it can boost immune activity [1.8.4]. By stimulating the immune system, ashwagandha can work against these medications, potentially reducing their effectiveness and leading to a worsening of the autoimmune condition or increasing the risk of organ transplant rejection [1.5.2, 1.5.3].
People with autoimmune conditions like rheumatoid arthritis, lupus, or multiple sclerosis should avoid ashwagandha [1.4.5].
Examples of immunosuppressants include:
- Corticosteroids like prednisone (Rayos®) [1.2.2].
- Organ transplant medications such as tacrolimus (Prograf®), cyclosporine, and azathioprine (Imuran®) [1.2.4, 1.2.5].
- Some biologics used for autoimmune conditions, like adalimumab (Humira®) [1.3.4].
Thyroid Medications
Ashwagandha has been found to increase the body's production of thyroid hormones, specifically triiodothyronine (T3) and thyroxine (T4) [1.6.3, 1.6.4]. For individuals taking thyroid hormone replacement medications for hypothyroidism (underactive thyroid), this can lead to an excess of thyroid hormones in the body, a condition called thyrotoxicosis [1.10.4]. Symptoms can include a fast or irregular heartbeat, nervousness, mood swings, and trouble sleeping [1.6.3]. Conversely, for those with hyperthyroidism (overactive thyroid), taking ashwagandha could worsen their condition [1.10.1].
It is recommended to use ashwagandha cautiously or avoid it if you have a thyroid condition or take medications like:
- Levothyroxine (Synthroid®, Levoxyl®) [1.2.4].
- Liothyronine (Cytomel®) [1.2.1].
- Desiccated thyroid (Armour Thyroid®) [1.2.4].
- Antithyroid medications like methimazole and propylthiouracil [1.2.1].
Diabetes Medications
Studies suggest that ashwagandha can lower blood sugar levels [1.7.4]. While this may be beneficial on its own, it poses a risk when combined with antidiabetic medications. The additive effect can cause blood sugar to drop to dangerously low levels, a state known as hypoglycemia [1.7.3]. Symptoms of hypoglycemia include dizziness, confusion, weakness, sweating, and hunger [1.7.2]. If you take medication for diabetes, you should monitor your blood sugar closely and consult your doctor before using ashwagandha [1.8.4].
Examples of diabetes medications include:
- Insulin [1.7.1].
- Metformin (Glumetza®) [1.2.2].
- Glipizide (Glucotrol®) [1.2.2].
- Semaglutide (Ozempic®, Wegovy®) [1.2.2].
Blood Pressure Medications
Similar to its effect on blood sugar, ashwagandha may also lower blood pressure [1.8.4]. For individuals already taking antihypertensive drugs, this combination can lead to hypotension, where blood pressure falls too low [1.3.4]. Symptoms include lightheadedness, dizziness, fainting, and weakness [1.8.1]. It is important to monitor blood pressure closely if combining these treatments [1.8.4].
This interaction applies to several classes of blood pressure drugs:
- ACE inhibitors, like ramipril (Altace®) [1.2.4].
- Angiotensin II Receptor Blockers (ARBs), like losartan (Cozaar®) [1.2.4].
- Beta-blockers, like atenolol (Tenormin®) [1.3.4].
- Calcium channel blockers, like amlodipine (Norvasc®) [1.3.4].
- Diuretics (“water pills”), like furosemide (Lasix®) [1.3.4].
Comparison of Ashwagandha Interactions
| Medication Class | Potential Interaction with Ashwagandha | Example Medications |
|---|---|---|
| Sedatives | Increased drowsiness, slowed breathing [1.4.5] | Alprazolam (Xanax®), Zolpidem (Ambien®) [1.4.1] |
| Immunosuppressants | Decreased medication effectiveness [1.5.2] | Prednisone, Tacrolimus (Prograf®) [1.2.2, 1.2.5] |
| Thyroid Medications | Risk of excessive thyroid hormone levels [1.6.3] | Levothyroxine (Synthroid®), Methimazole [1.2.4, 1.6.2] |
| Diabetes Medications | Risk of dangerously low blood sugar (hypoglycemia) [1.2.2] | Insulin, Metformin, Glipizide [1.2.4] |
| Blood Pressure Meds | Risk of dangerously low blood pressure (hypotension) [1.2.4] | Lisinopril, Amlodipine (Norvasc®), Losartan [1.5.3, 1.8.1] |
Conclusion
While ashwagandha is a popular herbal supplement with a long history of use, it is not without risks. Its ability to influence neurotransmitters, hormones, and the immune system means it can have significant interactions with many conventional medications. These interactions can either amplify a drug's effects to dangerous levels or counteract them, rendering treatments ineffective. Therefore, it is essential for anyone considering ashwagandha to first consult with a healthcare professional to review their current medications and health conditions. This proactive communication is the best way to ensure safety and avoid adverse outcomes.
