Ashwagandha and cortisol: what really drops, at what dose and when not to take it

Cortisol has become the culprit for everything: the belly, the puffy face, the five o'clock slump and the broken nights. And with the culprit came the remedy: ashwagandha, the ayurvedic root that now takes up half a shelf of supplements in any shop in Europe and turns up in almost every wellness video.

There is evidence behind it, more than a fashionable botanical usually has. But it does not say what the videos say, and there is one part — safety — that almost nobody mentions and that has moved half a dozen European agencies. Here is what is known, at what dose, and when it is better not to take it.

In short

• Yes, measured cortisol does go down. Two 2025 meta-analyses confirm it: one with 15 trials and 873 participants, another with 488 participants and a fall of 1.16 µg/dl.
• Lowering cortisol and feeling better are not the same thing. One of those two meta-analyses found no effect on perceived stress. The sources disagree and we explain it below.
• The effect is most consistent on sleep, above all from 600 mg a day and eight weeks onwards.
• Dose studied: 300-600 mg a day of standardised root extract. Below 250 mg there is little to hold on to.
• It is not for everyone. Pregnancy, breastfeeding, thyroid, autoimmune disease, liver disease, upcoming surgery and several medicines: in those cases, no.
• Ashwagandha has no authorised health claim in the EU. Magnesium and pantothenic acid do, with exact wording worth knowing.
• Genuinely "high cortisol" is a rare disease: 2 to 4 cases per million people per year. What almost everyone has is not that.

What cortisol is and why yours is almost never high

Cortisol is a steroid hormone made by the adrenal glands. It is not "the stress hormone" in the sense of always being in excess: it is the hormone that gets you out of bed. It follows a marked circadian rhythm — peaking thirty to forty minutes after waking, falling through the day, lowest in the middle of the night — and it regulates glucose, blood pressure and the immune response.

Two practical consequences follow. First: a single cortisol measurement means almost nothing, because a value at nine in the morning and another at nine at night are different numbers in the same healthy person. Second: a real, sustained excess has a name, Cushing's syndrome, and it is a rare disease, with an incidence of 2 to 4 cases per million people per year; the only Spanish population study, in Biscay, found a prevalence of 39.1 cases per million and 2.4 new cases per million per year (Lahera Vargas and da Costa, Endocrinología y Nutrición, 2009).

Put another way: "cortisol face" and "cortisol detox" do not exist as clinical entities. A puffy face in the morning is usually salt, alcohol, too little sleep or an allergy, and a hormonal problem is investigated with a blood test ordered by a doctor, not with a supplement. What does exist is a chronically activated stress response, and we cover it in the post on chronic stress and the nervous system.

What the evidence says about ashwagandha

1. It lowers measured cortisol, and that much is fairly clear

It is one of the few botanicals with several meta-analyses that agree. In BJPsych Open (2025), Bachour and colleagues pooled 15 randomised trials and 873 participants: at eight weeks cortisol fell by 2.36 units (95% CI: −3.26 to −1.46; p < 0.0001) and anxiety on the HAM-A scale dropped 3.52 points, while quality of life did not improve significantly (p = 0.37).

The second, in Nutrition and Health (Albalawi, 2025), gathered seven trials with 488 participants, doses of 250 mg a day or more and at least two weeks: a fall of 1.16 µg/dl (95% CI: −1.64 to −0.69; p < 0.001). If what you want is to move the number, it moves it. The products are in nervous system supplements and in plants and extracts.

2. Cortisol going down does not mean you feel better

Here is the myth worth dismantling, and it works against our own interest. The same Nutrition and Health meta-analysis that found the drop in cortisol found no effect on perceived stress: −0.355, with an interval crossing zero (95% CI: −1.188 to 0.47; p = 0.40). It says so in its own title.

And the sources disagree, so we say it: the BJPsych Open meta-analysis, with more trials, did find an improvement on the perceived stress scale at eight weeks (−4.88 points; 95% CI: −7.84 to −1.91). Both are probably right while measuring different things: cortisol is a biomarker and perceived stress is a questionnaire. The honest reading is that the effect on how you feel is real but small and inconsistent, and that the promise of "lower your cortisol and your life will change" runs well ahead of the data.

3. The effect is most consistent on sleep

Cheah and colleagues, in PLOS ONE (2021), pooled five trials and 400 participants with doses of 120 to 600 mg a day for 6 to 12 weeks. A small but significant effect: SMD −0.59 (95% CI: −0.75 to −0.42), with high heterogeneity (I² = 62%). The subgroups matter: at 600 mg or more, −0.69; at eight weeks or more, −0.68; with diagnosed insomnia, −0.84, against −0.63 in healthy adults. On the Pittsburgh index it did not reach significance (p = 0.150).

Translated: if you take it to sleep, doing so at a low dose for a few days is throwing money away. And if the sleep problem is about habits rather than physiology, no bottle fixes it. The sleep category is very thin on references right now, so look instead at coffee and teas.

4. Dose and standardisation are half the product

The NIH Office of Dietary Supplements lists trials with doses of 240 to 1,250 mg a day of extract — and up to 12,000 mg of root powder — with the clearest benefit between 500 and 600 mg a day; for generalised anxiety, a clinical working group provisionally recommends 300-600 mg of standardised root extract. The extracts used in the studies are standardised to 1.5%, 2.5% or 5% withanolides, the compounds credited with the effect.

This is what separates one product from another and it does not show in the photo: if the label does not state the percentage of withanolides or whether it is root or whole-plant extract, you do not know what you are buying. The NIH themselves warn that recommendations are hard to give because studies used very different preparations and doses. Compare labels before deciding.

5. Safety: the liver, the thyroid and the three-month ceiling

This is the part that does not appear in the videos. The NCCIH (NIH) considers ashwagandha safe in the short term, up to about three months, and notes there are not enough data on prolonged use. There are published cases of liver injury: a scoping review in Cureus (2026) gathered 25 patients across 13 publications, with a cholestatic pattern in 44%, hepatocellular in 32% and mixed in 20%; recovery in 80%, one transplant and three deaths. The NIH describe five cases at doses of 450 to 1,350 mg a day for between one week and four months.

These are small numbers against millions of consumers, and that has to be said too. But they change who you recommend it to. The NCCIH advises against it in pregnancy and breastfeeding, before surgery and in people with thyroid disorders or autoimmune diseases, and warns of interactions with antidiabetics, antihypertensives, immunosuppressants, antiepileptics and thyroid hormone. The usual adverse effects: digestive discomfort, loose stools, nausea and drowsiness.

On the regulatory side: Denmark banned it in foods and supplements in 2023, on the basis of a 2020 report by the National Food Institute (DTU) concluding that no safe intake limit could be set. France's ANSES and the Dutch RIVM advise against it in vulnerable groups, Germany's BfR published a risk assessment in 2013 and the UK's FSA opened a call for evidence in 2024. In Spain it is sold legally as a food supplement, which is not the same as saying it is harmless for everyone.

6. What can legally be claimed in Europe

No brand can tell you on its label that ashwagandha "reduces cortisol". Botanicals remain with their claims on hold and ashwagandha has no authorised health claim in the EU. Any benefit statement on a pack is, at best, a grey area under Regulation (EC) 1924/2006.

What is authorised, with exact wording and conditions in Regulation (EU) 432/2012:

• "Pantothenic acid contributes to normal synthesis and metabolism of steroid hormones, vitamin D and some neurotransmitters." It is the only one that touches cortisol's territory directly, cortisol being a steroid hormone. Condition: being a "source of" pantothenic acid, 15% of the reference value (0.9 mg).
• "Magnesium contributes to normal functioning of the nervous system", "contributes to normal psychological function" and "contributes to a reduction of tiredness and fatigue". Same condition: being a source of magnesium, 15% of the 375 mg reference value, that is 56.25 mg. That route is developed in the post on which magnesium to take, and the products are in vitamins and minerals.

What each study measured, in one table

How to take it without overcomplicating things

If you still think it fits your case, here is the practical part: format, dose, timing and a time limit.

One note that sells nothing: caffeine stimulates the same hormonal axis. If you sleep badly and drink coffee in the afternoon, moving the coffee is free and works faster than any capsule. We have decaffeinated coffee beans in bulk so you can try without buying a kilo.

The shopping list

The ashwagandha references in the catalogue and what usually goes with them:

Ashwagandha: Organic India, 90 capsules · Aldous with black pepper, 250 capsules · root powder Orgánica SuperFoods, 100 g · Sol Natural powder, 125 g · superfermented Orgánica SuperFoods, 21 g · Calmia Día formula by WeBotanix.

Other plants in the same conversation: tulsi, the rest of plants and extracts, the medicinal mushrooms and the superfoods.

The route with an authorised claim: magnesium bisglycinate and the rest of vitamins and minerals.

What you eat, which is where the match is played: pulses, rice, seeds, nuts and dried fruit, eggs, canned fish, oils and vinegars, spices and the rest of the pantry.

Fresh and chilled: vegetables, fermented foods and precooked and drinks. If you would rather we decided for you, there are the organic baskets.

And if the real reason is another one: digestive system, enzymes and probiotics, fatty acids, immune system, proteins and amino acids and hair, skin and nails.

Where to buy ashwagandha in Barcelona and Sant Cugat

This is exactly the supplement you should not buy blind, and here a physical shop beats any marketplace. At the counter you turn the bottle around and check the percentage of withanolides, whether it is root or whole-plant extract and how many milligrams a combination formula really contains. And you can say out loud "I take levothyroxine" and have someone tell you that in your case it is better not to. Amazon does not do that.

We have three shops:

• Provença 242, 08008 Barcelona — in the Eixample, between Balmes and Enric Granados.
• Còrsega 78, 08029 Barcelona — Eixample, near Sants station.
• Antoni Bell 2, 08174 Sant Cugat del Vallès — Volpelleres neighbourhood, next to the station.

If you would rather ask before coming over, the phone number is +34 683 118 961 and the email is linverd@linverd.com. And if you want it delivered, it is all in the online shop.

Do you need supplements to lower cortisol?

For the vast majority of people, no. The biggest and cheapest effect on the stress axis comes from two things we do not sell: sleeping seven or eight hours on a stable schedule and moving every day. A fall of 1.16 µg/dl of cortisol is a real result, but a small one next to what a week of decent sleep does.

Ashwagandha makes sense as bounded support: a specific period, a specific dose, a specific goal — usually sleep — and an end date. Not as a permanent bottle on the bedside table. And it makes no sense if you are pregnant, if your thyroid is affected, with an autoimmune disease or liver problems: there the balance does not add up. We would rather tell you than sell you the bottle.

Frequently asked questions

Does ashwagandha really lower cortisol?

Yes. Cortisol measured in blood or saliva falls in a statistically significant way: a 2025 meta-analysis with 488 participants found a drop of 1.16 µg/dl and another with 15 trials confirmed it at eight weeks. How much you notice that change is a different matter.

What dose of ashwagandha should you take?

Trials have used 240 to 1,250 mg a day of extract, with the clearest benefit between 500 and 600 mg. For anxiety, a clinical working group provisionally suggests 300-600 mg of standardised root extract. Below 250 mg a day there is little evidence.

Morning or night?

It depends on the goal. For sleep, night makes more sense, and the effect appears at around eight weeks, not on the first night. For daytime stress, split the dose with meals: it is better tolerated and causes fewer digestive complaints.

How long can you take it for?

The NCCIH considers it safe in the short term, up to about three months, and warns that data on prolonged use are missing. The sensible approach is cycles with an end and a review, not indefinite use. If you take long-term medication, check with your doctor first.

Who should not take ashwagandha?

Pregnant and breastfeeding women, people with thyroid disorders or autoimmune diseases, anyone due to have surgery soon and anyone with liver disease. Interactions with antidiabetics, antihypertensives, immunosuppressants, antiepileptics and thyroid hormone also need watching.

Is ashwagandha banned in Europe?

In some countries, yes: Denmark banned it in foods and supplements in 2023, France and the Netherlands advise against it in vulnerable groups and the United Kingdom opened a review in 2024. In Spain it is sold legally, but with no authorised health claim in the EU.

Where can I buy organic ashwagandha in Barcelona or Sant Cugat?

In the three Linverd Market shops: Provença 242 (08008 Barcelona), Còrsega 78 (08029 Barcelona) and Antoni Bell 2 (08174 Sant Cugat del Vallès, Volpelleres). We have eight references, in capsules and powder, and the whole catalogue online too with home delivery.

Drop by the shop or order online

If you want to compare labels with someone in front of you, come to Provença 242, Còrsega 78 or Antoni Bell 2, or call +34 683 118 961. If your mind is made up, nervous system and plants and extracts have everything mentioned here, and the rest of the health blog goes the same way.

Two earlier posts continue the conversation: Magnesium: bisglycinate, citrate or threonate, which to take and How much fibre per day you need and how to reach 25 g.

This article is for information only and does not replace advice from a healthcare professional. Food supplements should not be used as a substitute for a varied, balanced diet or a healthy lifestyle. If you are pregnant or breastfeeding, taking medication or living with a diagnosed condition — especially thyroid, autoimmune or liver disease — talk to your doctor or pharmacist before taking ashwagandha.