Ashwagandha and CBD together - is it safe 2026

Combining ashwagandha with CBD is one of the more popular protocols for supporting the stress system, yet it is also one of the least documented. Each of these substances has randomized clinical trials behind it. Their combination does not. This distinction is crucial for everything that can be said honestly about this combination, which is why we place it at the beginning rather than in a disclaimer at the end. In this text, we show what exactly was measured in studies on ashwagandha and CBD separately, where the evidence ends and extrapolation begins, what warnings are issued by safety assessment bodies, and who should avoid this combination regardless of the dose. We also provide a list of claims that we removed from the previous version of this article because the cited works did not contain them. The numbers here describe only the course of specific studies and are not recommendations for the reader.

KEY INFORMATION
- There is no randomized clinical trial on the simultaneous administration of ashwagandha and CBD in humans. Conclusions about synergy are extrapolations from separate studies of each substance.
- The extract from ashwagandha root reduced serum cortisol levels by 27.9% compared to 7.9% in the placebo group, in a 60-day study involving 64 individuals (Indian Journal of Psychological Medicine, 2012).
- CBD interacts with CYP3A4, CYP2C19, and P-glycoprotein, so the potential for interactions with commonly used medications is high, and adverse effects occurred in nearly half of users (Journal of Clinical Medicine, 2019).
- EFSA cannot determine the safety of CBD in individuals under 25 years of age, in pregnant and breastfeeding women, and in those taking medications (EFSA Journal, 2026).
- Ashwagandha raises thyroid hormone levels, which is an advantage in hypothyroidism and a problem in hyperthyroidism (Journal of Alternative and Complementary Medicine, 2018).

What is ashwagandha and what exactly was measured in studies about it?

Ashwagandha, or Withania somnifera, is a plant used for centuries in Ayurvedic medicine and has been studied in randomized clinical trials for the past several years as a stress-relieving agent. It is available as a dietary supplement, most commonly in the form of a standardized root extract.

The clinical studies cited by manufacturers are surprisingly few and all short. The three most frequently cited lasted 60 days, 60 days, and 10 weeks, respectively, with the largest trial involving 64 individuals. None of them measured what happens when CBD is taken simultaneously.

Note that the preparations are different. KSM-66 and Shoden are different extracts, with different standardizations and administered in different doses, so transferring results from one to another is not straightforward. We will break down the differences between them in a separate text about KSM-66 and Sensoril extracts.

What did Chandrasekhara's study on cortisol show?

This is the most frequently cited work on ashwagandha, and it is worth knowing it in detail because the figure of 27.9% circulates online out of context. The study was prospective, randomized, double-blind, and placebo-controlled. It involved 64 individuals with documented chronic stress who took a capsule twice daily for 60 days. The capsule contained 300 mg of highly concentrated full-spectrum root extract, which amounts to 600 mg per day (Indian Journal of Psychological Medicine, 2012).

In the active group, serum cortisol levels decreased by 27.9% after 60 days compared to baseline. In the placebo group, the decrease was 7.9%, and the difference between the groups was statistically significant. We read these values from the full text of the paper because only the significance level was provided in the abstract.

Who was included in this study also matters for interpreting the results. Participants were recruited from individuals who scored no higher than 15 points on the WHO-5 well-being questionnaire and reported a high level of stress on the perceived stress scale. A psychiatrist examined each of them to exclude primary mental disorders. Thus, it was not a trial of sick individuals, but of those burdened with chronic stress, and this is how one should read the transfer of these results onto oneself.

Questionnaire results also improved. In the GHQ-28 scale, the decrease in symptoms was 76.1% in the somatic subscale, 69.7% in the anxiety and insomnia subscale, 68.1% in the social dysfunction subscale, and 79.2% in the severe depression subscale. In the placebo group, the corresponding decreases were significantly smaller. It is important to pay attention to the labels: the figure of 69.7% describes one subscale of GHQ-28, not the entire questionnaire or the perceived stress scale.

The authors noted mild adverse effects, comparable in both groups, with no severe events. The product used in the study is explicitly named as KSM-66 extract in the full text. We discuss more about what lowers cortisol and what only claims to do so in the text about suplementach na stres i kortyzol.

What did studies on ashwagandha show regarding sleep and anxiety?

This image is more modest than marketing suggests. In a 2019 study, sixty patients with insomnia and anxiety were assigned in a two-to-one ratio to either root extract or starch as a placebo, administered twice daily for ten weeks. Sleep was measured using actigraphy, not just a questionnaire (Cureus, 2019).

The time to fall asleep was reduced in both groups, but after ten weeks it was significantly shorter in the active group: 29.00 minutes compared to 33.94 minutes in the placebo group, with a p-value of 0.019. Sleep efficiency increased from 75.63 to 83.48 in the active group and from 75.14 to 79.68 in the placebo group. The improvement in sleep quality was significant compared to placebo with a p-value of 0.002, as were the PSQI and HAM-A scale results.

A five-minute difference in sleep onset is a real but small result, and the authors themselves conclude that further studies with larger samples are needed. Nowhere in this paper is there a figure stating that the time to fall asleep was reduced by a quarter, although this claim circulates in Polish internet attributed to this study.

The second paper from the same year, published in the journal Medicine, examined 60 healthy adults with high stress levels over 60 days. Shoden extract was administered once daily at a dose of 240 mg. A significant decrease in the HAM-A scale was observed compared to placebo with a p-value of 0.040, and the decrease in the DASS-21 scale was close to significance. Hormonal changes were more pronounced: a decrease in morning cortisol with p below 0.001 and a decrease in DHEA-S (Medicine, 2019).

How does CBD work and what was measured in anxiety studies?

The most frequently cited work on CBD in anxiety is a retrospective analysis of documentation from a psychiatric clinic. Records of 103 adult patients were reviewed, and the final analysis included 72 individuals primarily reporting anxiety or poor sleep quality (The Permanente Journal, 2019).

Anxiety severity decreased in the first month for 57 patients, or 79.2%, and remained at a reduced level throughout the observation period. Sleep results improved in the first month for 48 patients, or 66.7%, but fluctuated in the following months. CBD was well tolerated by all patients except for three.

Three caveats must be added to these numbers, and they are not mere formalities. This is not a randomized or blinded study, but a review of patient records who were concurrently treated in the usual way. There was no control group, so it is impossible to separate the effects of CBD from the natural course and from the other therapy. The authors themselves conclude that controlled clinical trials are needed.

A separate issue is the descriptions of the mechanism. Statements about CBD's action on the 5-HT1A receptor and the inhibition of the FAAH enzyme come from preclinical studies, and in Polish texts, they are sometimes supported by a paper that does not include them at all. This earlier version of the article did the same: citations led to a review of terpenes and the entourage effect, rather than any study of bioavailability or receptor affinity.

Is there a study on combining ashwagandha with CBD?

There is not. We found not a single randomized clinical trial in which ashwagandha and CBD were administered simultaneously to the same group of people and measured against a control group. All the studies mentioned above examined each substance separately, and none report that participants were concurrently taking the other.

This means that any statement about the effects of the combination is an inference, not a measurement. Inference can be justified, but it comes at a cost: we do not know whether the effects add up, cancel each other out, or if one alters the fate of the other in the body. We also do not know the safety profile of such a combination, as no one has collected it.

It is worth noting how easily this gap disappears from texts about supplements. It is enough to write "the mechanisms are complementary" and add two citations, one for each substance. Formally, everything checks out, and the reader walks away with the impression that they have read about a study that does not exist. We noticed while organizing this text that this is the most common construction in the entire category of content about combining supplements.

The practical conclusion is not "do not combine". It is: since there is no data on the combination, the reference point for safety remains what is known about each substance individually, plus common sense regarding overlapping effects. This is precisely what the following sections address.

Why are the mechanisms of these two substances considered complementary?

The argument for complementarity is based on the fact that the substances target the stress system at different points. Ashwagandha affects the hypothalamic-pituitary-adrenal axis, as evidenced by changes in hormone levels: in a 2019 study, both morning cortisol and DHEA-S decreased, and the authors directly link the stress-reducing effect to the modulation of this axis (Medicine, 2019).

On the CBD side, we simply do not have a comparable hormonal measurement. The clinical study cited by this article recorded the severity of symptoms reported by the patient, not hormone levels. This difference in levels of description gives rise to the intuition of non-overlapping effects, and it should be remembered that this is intuition, not a result of comparison. Separately, it is worth noting that EFSA lists histopathological changes in the adrenal glands among hormonal disorders after CBD, so the thesis of CBD's neutrality towards this axis has no basis.

The second argument concerns time. The effect of ashwagandha in the cited studies was measured after 60 days or 10 weeks, as there simply is no effect earlier. The effect of CBD in the psychiatric clinic analysis appeared in the first month. The divergence of timelines is real, although none of these studies examined what happens when both courses are overlapped.

It must be honestly added where this argument ends. The complementarity of mechanisms is not the same as the synergy of effects. Two substances can act at different points and still not provide anything more together than what the stronger one offers. This is resolved solely by studying the combination, and such a study does not exist. We expand on this topic in the text about the synergy of CBD and adaptogens.

Does combining ashwagandha and CBD pose a risk of drug interactions?

The greatest risk of this combination does not lie in how both substances act on each other, but in how CBD acts on medications. A review published in the Journal of Clinical Medicine analyzed information about medicinal products containing CBD and reached a clear conclusion: since CBD interacts with CYP3A4 and CYP2C19, which are enzymes that metabolize drugs, as well as with P-glycoprotein responsible for excretion, the potential for interactions with commonly used medications is high (Journal of Clinical Medicine, 2019).

This same paper provides a number worth remembering. Adverse effects occurred in nearly half of those using CBD and showed a general dose-dependent relationship. The most common included increased aminotransferase activity, drowsiness, sleep disturbances, infections, and anemia. The authors describe CBD as both a victim and a perpetrator of drug interactions.

The recommendations from this paper are specific and directed to the physician, not the patient: consider reducing the dose of the drug metabolized via the same pathway, monitor adverse effects, or seek alternative therapy, with particular attention to patients burdened with multiple diseases. This is why, when on continuous pharmacotherapy, the decision to add CBD is made with the attending physician, not independently.

We did not find any threshold dose in this paper below which interactions would not occur. The claim that the risk only begins above a certain number of milligrams per day stood in the previous version of this article and has no support in the cited source. The relationship is described as generally dose-dependent, without indicating a threshold.

What does EFSA say about the safety of CBD itself?

The most recent and cautious assessment was issued in 2026 by the EFSA panel on nutrition and novel foods, updating its position from 2022. Using the benchmark dose method, with an uncertainty factor of 400, a temporary safe dose of 0.0275 mg per kilogram of body weight per day was derived, which is about 2 mg daily for a person weighing 70 kg (EFSA Journal, 2026).

This value is conditioned. It applies only to supplements with a CBD purity of no less than 98%, without nanoparticles, produced by a recognized safe process, and excluding genotoxicity. It does not apply to other forms.

However, the most important sentence of this document concerns not the number, but the gaps. The panel states that the safety of CBD cannot be determined in individuals under 25 years of age, in pregnant and breastfeeding women, and in individuals taking medications simultaneously is unknown. Animal studies have shown consistent liver toxicity, and in human studies, the potential hepatotoxicity was especially revealed when medications were used concurrently. Hormonal disorders were also noted, including altered thyroid hormone levels, and no one has yet studied immunotoxicity.

The panel explains why the gaps from 2022 have still not been closed. The literature review included animal and human studies up to June 2024, and new studies turned out to be burdened with methodological limitations: non-standardized protocols, short observation times, and concurrent pharmacological treatment of participants. Thus, four years of new publications did not shift the assessment to where the panel would like it to be.

Two additional findings directly concern the method of administration. Pharmacokinetic studies have confirmed that the bioavailability of CBD is variable and depends on the carrier as well as whether the supplement was taken with a meal. Gastrointestinal side effects were reported at higher doses, and the panel deemed the data on neurological and psychiatric safety insufficient.

For the topic of this article, a specific point arises. The thyroid thread appears in the EFSA assessment on the side of CBD and emerges in studies on ashwagandha on the side of the plant, which means that with this particular combination, thyroid parameters deserve separate attention. There is no data indicating what happens when both influences are summed.

What does ashwagandha do to the thyroid?

This thread is the best-documented contraindication part of the entire topic. In a randomized double-blind study, fifty patients with subclinical hypothyroidism, aged 18 to 50 years and with TSH levels ranging from 4.5 to 10 units per liter, were assigned to either an ashwagandha root extract at a dose of 600 mg per day or to starch as a placebo for eight weeks (Journal of Alternative and Complementary Medicine, 2018).

After eight weeks, ashwagandha significantly improved all three measured parameters compared to placebo: TSH with p below 0.001, T3 with p equal to 0.0031, and T4 with p equal to 0.0096. The authors describe this as normalization of thyroid indicators in this group of patients. Mild and transient side effects were reported by 8% of the subjects, with one person in the active group and three in the placebo group.

A favorable result in hypothyroidism turns into a warning in the opposite condition. Since the extract raises thyroid hormone levels, in a person with hyperthyroidism or Graves' disease, it pushes parameters in a direction that treatment aims to avoid. The same applies to individuals taking levothyroxine, for whom adding ashwagandha may require a dose adjustment after checking TSH.

It is worth emphasizing what this study does not say. It involved fifty people over eight weeks, in one diagnostic group, and the authors themselves call it a pilot study. We develop the thyroid thread further in the text about ashwagandha in subclinical hypothyroidism.

Four groups should not use this combination without medical consultation: pregnant and breastfeeding women, individuals with hyperthyroidism, individuals with autoimmune diseases, and patients on sedative or immunosuppressive medications. For most other adults, the combination is safe at typical clinical doses (

Four groups have clear support in the cited sources, and in each of them, the decision lies with the doctor, not the reader. The first is pregnant and breastfeeding women. EFSA states outright that the safety of CBD in this group cannot be established, citing placental transfer, systemic accumulation, and observed neurodevelopmental effects after prenatal exposure as reasons.

The second group consists of individuals taking medications regularly. Here, the warning signal comes from two sides at once: EFSA notes the potential hepatotoxicity of CBD, especially in combination with medications, and a review of interactions describes a high potential for interactions through liver enzymes and P-glycoprotein (Journal of Clinical Medicine, 2019).

The third group includes individuals with hyperthyroidism or those treated for thyroid diseases, for reasons described in the previous section. The fourth group consists of individuals under 25 years of age, mentioned by EFSA alongside pregnancy and pharmacotherapy as a group for which the safety assessment of CBD cannot be conducted based on available data.

It is also worth mentioning sedation, although here we rely on pharmacology rather than on the study of combinations. Ashwagandha has been studied as a sleep aid, and drowsiness is among the frequently reported side effects of CBD. The overlap of these effects with sedative medications or alcohol has not been measured, and for this reason, nothing reassuring can be said about it.

How long did these studies last and what are the implications?

The answer is short and has practical consequences. The longest of the cited studies on ashwagandha lasted ten weeks, two others lasted sixty days each, and the thyroid study lasted eight weeks. The analysis concerning CBD included observation conducted over several months, but without a control group and without blinding.

Therefore, we do not have data on the use of any of these substances for longer than a few months, and we have no data on their combined use at all. Statements about safety over the course of a year or longer, which regularly appear in texts about supplements, have no support in these studies.

This has implications for the popular advice on cycles with breaks. The advice can be reasonable, but it is important to know where it comes from: not from a study comparing continuous use with cyclical use, as such a study does not exist, but from caution due to the lack of data. This is a significant difference and it is worth naming it, rather than providing weekly schemes as if someone had measured them.

The same applies to monitoring parameters. Checking TSH with prolonged use of ashwagandha and monitoring aminotransferase activity with CBD are recommendations resulting from the direction of changes described in the cited studies. The frequency of such checks is determined by the doctor based on the patient's condition, not by a table in an article.

What unsupported claims about this combination are circulating?

In organizing this text, we removed several sentences whose sources were not confirmed. It is worth mentioning them, as they all circulate on Polish supplement websites and the reader will encounter them elsewhere.

The common denominator of these five items is one: each sounds precise and each gives the reader a number that can be measured. However, precision here is a feature of style, not measurement. When it comes to supplements, it is worth applying a simple test: if a sentence provides an exact number, check whether the cited work actually measured what that number describes.

Are ashwagandha and CBD legal in Poland?

Both substances are legally available in Poland, although on different grounds. Ashwagandha is marketed as an ingredient in dietary supplements. It is worth remembering that a sanitary notification about introducing a supplement to the market is not an authorization, but a notification, and does not itself determine the status of the ingredient.

CBD does not appear in any list of controlled substances. The word "cannabidiol" does not occur even once in the regulation of the Minister of Health regarding the list of psychotropic substances, narcotic drugs, and new psychoactive substances (Dz.U. 2024 poz. 1139).

A separate issue is the threshold for THC content, around which the most misunderstandings have arisen. According to Article 4, point 5 of the Act on Counteracting Drug Addiction, industrial hemp refers to plants of the species Cannabis sativa L., in which the sum of delta-9-THC and tetrahydrocannabinolic acid in flowering or fruiting tops does not exceed 0.3% when calculated on a dry weight basis, rounded to one decimal place. The basis is the consolidated text of the act (Dz.U. 2023 poz. 1939) as amended by the Act of March 24, 2022.

Two clarifications have practical significance. The threshold applies to the plant, not the finished product, and it is calculated as the sum of delta-9-THC and THCA, not just delta-9-THC alone. This distinction changes the result of laboratory testing, so a product description that omits it describes a different measurement than that provided by the law. The national threshold corresponds to the EU threshold, but it does not imply that they are the same: these are two separate regulations with the same numerical value.

Summary: is it worth combining ashwagandha with CBD?

The honest answer is: it's unclear, and that's not an evasion. Each of these substances has randomized studies behind them, but their combination has none, which means that the benefit of combining them remains a hypothesis, not a conclusion.

What is known for sure about ashwagandha itself: an extract from the root reduced serum cortisol levels by 27.9% compared to 7.9% in the placebo group in a 60-day study involving 64 participants, and in a sleep study, it shortened the time to fall asleep by a few minutes compared to placebo. All these trials were short and small.

What is known about CBD itself: in a review of records from 72 patients at a psychiatric clinic, anxiety severity decreased in the first month for 79.2% of individuals, but without a control group. On the safety side, the picture is sharper than on the efficacy side, as adverse effects occurred in nearly half of users, and EFSA cannot determine safety for individuals taking medications.

The practical conclusion for the reader boils down to three things. If you are on permanent medication, consulting with a doctor or pharmacist should precede any decision to add CBD. If you have a thyroid diagnosis, ashwagandha requires supervision from an endocrinologist. If you are pregnant, breastfeeding, or under 25 years old, the available data do not allow CBD to be considered safe, and there is no room for personal risk assessment.

Frequently Asked Questions

Is there a study on the combination of ashwagandha and CBD?

We did not find any randomized clinical trials on the simultaneous administration of both substances to humans. All available studies examined ashwagandha or CBD separately. Therefore, any statement about the effects of the combination is an extrapolation from separate studies, not a result of measuring the combination itself.

How much does ashwagandha lower cortisol?

In a 60-day randomized study involving 64 individuals with chronic stress, serum cortisol levels decreased by 27.9% in the group taking the extract and by 7.9% in the placebo group (Indian Journal of Psychological Medicine, 2012). Participants took a 300 mg capsule twice daily.

Does CBD interact with medications?

Yes. CBD interacts with CYP3A4 and CYP2C19 as well as P-glycoprotein, which means the potential for interactions with commonly used medications is high (Journal of Clinical Medicine, 2019). The review does not provide a dosage threshold below which risk would not occur.

What dose of CBD does EFSA consider safe?

The temporary safe dose is 0.0275 mg per kilogram of body weight per day, which is about 2 mg daily for a person weighing 70 kg (EFSA Journal, 2026). This applies only to supplements with CBD purity of no less than 98%, without nanoparticles.

Is it safe to use ashwagandha with CBD during pregnancy?

No. EFSA states that the safety of CBD in pregnant and breastfeeding women cannot be established, pointing to transplacental transfer and observed neurodevelopmental effects after prenatal exposure (EFSA Journal, 2026). There is also a lack of data for ashwagandha in this group.

Does ashwagandha affect the thyroid?

Yes. In an eight-week study involving 50 patients with subclinical hypothyroidism, the root extract significantly improved TSH, T3, and T4 levels compared to placebo (Journal of Alternative and Complementary Medicine, 2018). The same direction of change is undesirable in hyperthyroidism.

How much ashwagandha was administered in sleep studies?

In a study involving 60 patients with insomnia and anxiety, 300 mg of root extract was administered twice daily for ten weeks. The time to fall asleep was 29.00 minutes after this therapy compared to 33.94 minutes in the placebo group (Cureus, 2019). This is a description of the study protocol, not a recommendation for the reader.

Yes, both supplements are legal in Poland. Ashwagandha is allowed for sale as a dietary supplement according to the GIS register. CBD derived from hemp Cannabis sativa L. is legal if the THC content does not exceed 0.3% (

Yes. Ashwagandha is available as an ingredient in dietary supplements, and cannabidiol is not listed in any controlled substance lists (Dz.U. 2024 poz. 1139). The legal threshold of 0.3% applies to the plant and is calculated as the sum of delta-9-THC and THCA.

You can find plant extracts used in stress research in our category adaptogens.

This article is for informational and educational purposes only and does not constitute medical advice. Before starting to use hemp or CBD for therapeutic purposes, consult your doctor, especially if you are taking other medications, are pregnant, or breastfeeding.

Author: Michał Waluk · Opublikowano: 2026-05-11 · Aktualizacja: 2026-08-10