Ashwagandha and medications.
Ashwagandha is in the Distil supplement database, evidence Grade A. The page below lists every medication we have explicitly assessed it against.
Ashwagandha is an adaptogenic herb best evidenced for lowering cortisol and improving stress resilience, where the trials are Grade A; its effects on testosterone, sleep, and thyroid sit at Grade B, meaning promising but less settled. It works on the HPA axis, the body's stress response system. Only the standardised KSM-66 and Sensoril extracts have been trialled, at 300 to 600mg and 125 to 250mg respectively; raw powder is not equivalent. One trial found KSM-66 normalised thyroid markers in subclinical hypothyroidism, but for the same reason we leave it out for anyone with an overactive thyroid. The interactions need care. It can alter thyroid hormone levels, so flag it if you take thyroid medication. It adds to the sedation of benzodiazepines, and may interfere with immunosuppressants, so avoid it after a transplant, and we leave it out for anyone with an autoimmune condition, Hashimoto's included. Rare, idiosyncratic liver injury has also been reported, so avoid it if you have existing liver disease or raised liver enzymes, and stop and see a doctor promptly on any sign of liver trouble such as jaundice, dark urine or unusual fatigue. Never start it at the same time as Rhodiola; stagger by at least four weeks. Avoid in pregnancy. If used beyond eight weeks, taper over a week or two rather than stopping abruptly.
Below are the 19 documented pairs we have explicitly assessed for Ashwagandha: 19 caution. The pairs cluster around 5 mechanisms: Additive CNS depression, Immune-stimulant vs immunosuppressant (precautionary), Additive serotonergic activity, Calming effect vs stimulant (opposing), and Additive thyroid-hormone effect. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 13 October 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Additive CNS depression
Caution Does Ashwagandha interact with Alprazolam?
Ashwagandha can have a mild sedating effect on top of its main anti-stress action. Combined with alprazolam, the sedation can stack. Use with care around driving or heavy machinery.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Clonidine?
Ashwagandha can have a calming, mildly sedating effect and improves sleep for some people, and clonidine commonly causes drowsiness and tiredness. Taken together they may add to the sedation. Use with care, particularly around driving, and especially in the first weeks.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Diazepam?
Ashwagandha can have a mild sedating effect on top of its main anti-stress action. Combined with diazepam, the sedation can stack. Use with care around driving or heavy machinery.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Guanfacine?
Ashwagandha can have a calming, mildly sedating effect and improves sleep for some people, and guanfacine commonly causes drowsiness and tiredness. Taken together they may add to the sedation. Use with care, particularly around driving, and especially in the first weeks.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Lorazepam?
Ashwagandha can have a mild sedating effect on top of its main anti-stress action. Combined with lorazepam, the sedation can stack.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Temazepam?
Ashwagandha can have a mild sedating effect on top of its main anti-stress action. Combined with temazepam, the nocturnal sedation can stack.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Immune-stimulant vs immunosuppressant (precautionary)
Caution Does Ashwagandha interact with Ciclosporin?
Ciclosporin works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Ashwagandha has been reported to do the opposite and gently stimulate the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start ashwagandha while you take ciclosporin without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Ashwagandha has been reported to do the opposite and gently stimulate the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start ashwagandha while you take tacrolimus without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive serotonergic activity
Caution Does Ashwagandha interact with Citalopram?
Ashwagandha may interact with citalopram. In people taking other SSRI antidepressants, side effects that eased once ashwagandha was stopped have been reported, and one person on escitalopram, the closest relative of citalopram, developed serotonin toxicity after a large dose of ashwagandha. No report involves citalopram itself, but it works the same way, so speak to your GP or pharmacist before starting ashwagandha and get urgent help if you notice twitching, agitation, fever or a racing heart.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Escitalopram?
Ashwagandha may interact with escitalopram. Side effects that eased once ashwagandha was stopped have been reported in people taking both, and one person developed serotonin toxicity (muscle jerks, fever, a racing heart) after a large dose of ashwagandha on top of escitalopram. These are rare reports rather than proof, but speak to your GP or pharmacist before starting ashwagandha, and get urgent help if you notice twitching, agitation, fever or a racing heart.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Fluoxetine hydrochloride?
Ashwagandha may interact with fluoxetine. In people taking other SSRI antidepressants, side effects that eased once ashwagandha was stopped have been reported, and one person on escitalopram developed serotonin toxicity after a large dose of ashwagandha. No report involves fluoxetine itself, but it works the same way, so speak to your GP or pharmacist before starting ashwagandha and get urgent help if you notice twitching, agitation, fever or a racing heart. Fluoxetine stays in the body for weeks after stopping, so this applies for a while afterwards too.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Fluvoxamine?
Ashwagandha may interact with fluvoxamine. In people taking other SSRI antidepressants, side effects that eased once ashwagandha was stopped have been reported, and one person on escitalopram developed serotonin toxicity after a large dose of ashwagandha. No report involves fluvoxamine itself, but it works the same way, so speak to your GP or pharmacist before starting ashwagandha and get urgent help if you notice twitching, agitation, fever or a racing heart.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Paroxetine hydrochloride?
Ashwagandha may interact with paroxetine. A woman taking both developed widespread muscle pain, eye pain and raised pressure in the eye that eased once she stopped the ashwagandha, and similar reports exist with other SSRI antidepressants, including one case of serotonin toxicity with escitalopram. These are rare reports rather than proof, but speak to your GP or pharmacist before starting ashwagandha, and get urgent help if you notice twitching, agitation, fever or a racing heart.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Sertraline?
Ashwagandha may interact with sertraline. A man taking both developed severe diarrhoea needing hospital care that eased once he stopped the ashwagandha, and similar reports exist with other SSRI antidepressants, including one case of serotonin toxicity with escitalopram. These are rare reports rather than proof, but speak to your GP or pharmacist before starting ashwagandha, and get urgent help if you notice twitching, agitation, fever or a racing heart.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Calming effect vs stimulant (opposing)
Caution Does Ashwagandha interact with Dexamfetamine sulfate?
Ashwagandha is calming and mildly sedating, while dexamfetamine is a stimulant, so the two pull in opposite directions. In theory ashwagandha could take the edge off how well your medication works, or change how settled or wired you feel. No studies have tested the two together in people, so this is a watch-and-see caution rather than a hard rule. If you take both, keep an eye on whether your focus, sleep, or heart rate feel different, and do not change your stimulant dose without your prescriber knowing.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Lisdexamfetamine dimesylate?
Ashwagandha is calming and mildly sedating, while lisdexamfetamine is a stimulant, so the two pull in opposite directions. In theory ashwagandha could take the edge off how well your medication works, or change how settled or wired you feel. No studies have tested the two together in people, so this is a watch-and-see caution rather than a hard rule. If you take both, keep an eye on whether your focus, sleep, or heart rate feel different, and do not change your stimulant dose without your prescriber knowing.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Methylphenidate hydrochloride?
Ashwagandha is calming and mildly sedating, while methylphenidate is a stimulant, so the two pull in opposite directions. In theory ashwagandha could take the edge off how well your medication works, or change how settled or wired you feel. No studies have tested the two together in people, so this is a watch-and-see caution rather than a hard rule. If you take both, keep an eye on whether your focus, sleep, or heart rate feel different, and do not change your stimulant dose without your GP knowing.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive thyroid-hormone effect
Caution Does Ashwagandha interact with Carbimazole?
Carbimazole is given to bring an overactive thyroid down. Ashwagandha tends to push thyroid hormone the other way, up, so it can work against your treatment. It is best not to add ashwagandha while you are being treated for an overactive thyroid. If you already take both, tell your GP and have your thyroid bloods checked.
Evidence: Supported by human study data.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Caution Does Ashwagandha interact with Levothyroxine?
Ashwagandha on top of levothyroxine can tip you into having too much thyroid hormone, because ashwagandha can raise your body's own thyroid output on top of your dose. Watch for a racing heart, feeling wired, or unexpected weight loss, and ask your GP to check your thyroid blood tests if you take both. Do not change your levothyroxine dose yourself.
Evidence: Supported by human study data.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
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How the checker decides
Every result has a source
Each pair we have assessed is cited to a published study (PMID) or the British National Formulary, so you can read the source yourself.
Four kinds of answer
Severe, caution, no known interaction, and not yet assessed. A pair we have not assessed is never shown as clear.
- Severe
- Caution
- No known interaction
- Not yet assessed
Nothing in our data is not a clearance
When nothing in our data records a problem with a pair, the result says no known interaction at typical doses, which is not a clearance: your pharmacist or GP can check the pair against your full medical history.
A full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
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