Ashwagandha (Withania somnifera)
Ashwagandha (Withania somnifera) is a small evergreen shrub in the Solanaceae family, native to India and parts of the Middle East and North Africa. It has a long history of use in traditional Ayurvedic medicine, where the root is used as a tonic and adaptogen. It is sold in the UK as a food supplement, typically as a standardised root extract. There are no authorised UK food-supplement health claims for ashwagandha; trial evidence for stress, sleep, and related outcomes is concentrated on specific branded extracts (KSM-66, Sensoril, Shoden) at specific durations.
Camden Medicals editorial · Last reviewed 12 June 2026 · Next review December 2026
- Cross-checked against
- NHS
- NICE
- BNF
- EFSA
- FSA
Camden's own editorial team graded each health claim below on the strength of the published evidence — trials weighed with Cochrane RoB 2, systematic reviews with AMSTAR 2, under the CEGA method. See the grade beside every condition.
- Class
- Botanical
- Typical daily dose
- Trials of KSM-66 root extract have most commonly used 600 mg/day (300 mg twice daily) of extract standardised to ≥5% withanolides. Sensoril trials have used 125–250 mg/day at ≥10% withanolides. Generic powder or unstandardised X:1 extract at the same milligram delivers a lower and unstandardised withanolide dose and is not directly comparable.
- Top use evidence
- Limited
On this page
- What it is
- At a glance
- What people use it for
- How it works
- Common myths
- Common online questions
- The official position
- What the guidance says
- Camden's evidence review
- Safety, interactions & who should avoid it
- How to take it
- How to spot quality
- Commonly combined with
- Related ingredients
- Verifera® editorial perspective
- Sources
- How this entry was researched
What it is
Withania somnifera is a small woody perennial shrub in the Solanaceae (nightshade) family, native to dry regions of India, the Middle East, and parts of North Africa. The species name "somnifera" is Latin for "sleep-bearing", reflecting traditional use as a tonic. The English common name "ashwagandha" is from Sanskrit, meaning "smell of horse" (a description of the root's aroma, sometimes also taken as a metaphor for the strength traditionally associated with the herb).
The bioactive compounds most discussed are the withanolides — a family of naturally occurring steroidal lactones, including withaferin A and the withanosides. Modern clinical trials have used extracts standardised by total withanolide content, typically 1.5–10%. The most-used branded preparations are KSM-66 (Ixoreal Biomed; full-spectrum root extract, ≥5% withanolides by HPLC, water-only extraction), Sensoril (Natreon; root + leaf, ≥10% withanolides), and Shoden (Arjuna Natural; root, 35% withanolide glycosides).
Standardisation by withanolide content is the relevant quality marker — a 500 mg capsule of generic "ashwagandha root powder" and a 500 mg capsule of KSM-66 standardised root extract are not directly comparable. The same is true of unstandardised X:1 extract ratios that do not declare withanolide percentage.
At a glance
- A traditional Ayurvedic herb (Withania somnifera, also called Indian winter cherry) sold in the UK as a food supplement.
- No UK-authorised health claims; botanicals are on EFSA hold. Trial wording is descriptive only.
- Trial evidence is concentrated on specific standardised root extracts — KSM-66 (≥5% withanolides), Sensoril, Shoden. Generic "ashwagandha powder" or unstandardised X:1 extract at the same milligram tells you nothing comparable.
- Trial benefit signals (perceived stress, sleep quality, exercise outcomes) emerge over 4–12 weeks of daily use, not acutely.
- Pregnancy: avoid. Thyroid disease: talk to your prescriber. The UK FSA / COT are reviewing ashwagandha's safety (possible liver, thyroid and blood-sugar effects) — discontinue and seek advice if symptoms of liver irritation develop.
What people use it for
Adults exploring supplements alongside lifestyle measures for self-reported stress
A small literature on standardised KSM-66 root extract (300 mg twice daily) has reported lower self-reported stress-scale scores and lower morning cortisol over 8–12 weeks. Effect sizes are modest. UK NHS pathways for anxiety apply (NICE CG113 for GAD); ashwagandha is not on those pathways. [2]
Some evidenceLimitedAdults with self-reported difficulty falling asleep, alongside sleep hygiene
Small RCTs of KSM-66 600 mg/day for 8 weeks have reported lower self-reported sleep-onset latency and higher sleep-quality scale scores. UK NHS pathways for insomnia apply; ashwagandha is not a UK-recognised treatment. [1]
Some evidenceLimitedResistance-trained adults exploring exercise-recovery supplementation
A handful of trials in resistance-trained men have reported small increases in upper- and lower-body strength markers and changes in body composition with KSM-66 600 mg/day across 8–12 weeks. Trial sizes are small. Ashwagandha is not an authorised performance claim.
Some evidenceLimitedAdults considering ashwagandha for diagnosed anxiety, depression, ADHD, or thyroid disease
Ashwagandha is not a UK-recognised clinical pathway for any of these conditions. UK NHS / NICE pathways apply (CG113 anxiety, NG222 depression, NG87 ADHD, NG145 thyroid disease). Talk to your GP or prescribing pharmacist. [2,3,4,5]
Popular, not provenInsufficientAdults wanting an acute calming or focus boost
Ashwagandha is positioned as a chronic-use supplement in the trial literature. There is no reliable single-dose acute effect on stress or cognitive function. If acute calming is the goal, this is not the right ingredient.
Popular, not provenInsufficientAdults exploring traditional Ayurvedic botanicals
Long history of traditional Ayurvedic use. Traditional-use framing is permissible; specific UK food-supplement health claims are not authorised.
Some evidenceLimited
How it works
Withanolides have been studied for effects on the hypothalamic-pituitary-adrenal (HPA) axis (cortisol modulation in stressed adults), GABAergic signalling (proposed sleep and relaxation effects), and skeletal-muscle anabolic markers (resistance-training trials). The most-reported clinical endpoint is reduction in self-reported stress scale scores (e.g., PSS-10) and circulating cortisol over 8–12 weeks of daily standardised-extract use. Acute / single-dose effects are not the primary endpoint in the trial literature — ashwagandha is positioned as a chronic-use supplement in trial protocols, not as an acute calming agent.
Common myths
Myth"Ashwagandha is a "natural Xanax" or "natural Adderall""
RealityIt is neither. Xanax and Adderall are Prescription-Only Medicines with defined acute pharmacological action, dependence liability, and prescribing rules. Ashwagandha is a chronic-use food supplement; trial endpoints emerge at 4–12 weeks and effect sizes on self-report scales are modest. The benzodiazepine and stimulant comparisons are marketing language, not clinical equivalence.
Myth"Ashwagandha works the first day you take it"
RealityTrials have reported effects emerging at 4–12 weeks, not acutely. The acute / single-dose effect is small and not the primary trial endpoint. Marketing implying same-day stress reduction is not supported by the trial protocols.
Myth"A "30:1 ashwagandha extract" is thirty times stronger than the powder"
RealityExtract ratios describe how many kilograms of starting raw ashwagandha were processed to yield one kilogram of extract. They do not describe the withanolide content. The relevant quality marker is withanolide percentage standardisation by HPLC. A "30:1 extract" with no withanolide percentage tells you nothing comparable to the trial materials. KSM-66, by contrast, declares ≥5% withanolides on every batch.
Myth"Ashwagandha is a remedy for diagnosed anxiety / depression / ADHD"
RealityIt is not a UK-recognised pathway for any of these conditions. UK NHS / NICE pathways apply (CG113 anxiety, NG222 depression, NG87 ADHD). Self-supplementation in place of formal assessment and management is not appropriate. [2,3,4]
Myth"Ashwagandha is a natural HRT or testosterone booster"
RealityA handful of small trials in men have reported modest changes in serum testosterone with KSM-66 supplementation. Effect sizes are small and trial sizes are limited. Marketing as a hormone-replacement substitute or as a treatment for clinical hypogonadism is not supported. UK NHS pathways for hypogonadism apply.
Myth"Ashwagandha is naturalness-as-safety — therefore safe in pregnancy"
RealityIt is not. Standard Ayurvedic and modern guidance is to avoid ashwagandha in pregnancy and lactation. The traditional-use framing does not override the absence of human pregnancy safety data and the presence of early-pregnancy effects in animal studies.
Common online questions
Synthesised from the questions UK shoppers most often ask online about Ashwagandha (Withania somnifera). Each answer is editorial and links to its evidence in the Sources list below.
How long does ashwagandha take to work?
The published trials report effects emerging at 4–12 weeks of daily use, with most stress / cortisol endpoints assessed at 8 weeks and most sleep endpoints at 6–8 weeks. There is no reliable single-dose acute effect — ashwagandha is a chronic-use supplement in the trial literature, not an acute calming agent. If you don''t notice anything in the first days, that is consistent with the trial evidence; reassess at 8 weeks or stop.
KSM-66 vs Sensoril vs generic root extract — does it matter?
For trial-comparable supplementation, the standardised branded extracts are what the literature has used. KSM-66 (Ixoreal Biomed) is a full-spectrum water-extracted root preparation standardised to ≥5% withanolides — used in the majority of stress and sleep trials. Sensoril (Natreon) is a root + leaf preparation standardised to ≥10% withanolides — used in some cognitive trials. Generic "ashwagandha powder" or X:1 extract at the same milligram delivers an undeclared and lower withanolide dose and is not directly comparable to the trial materials.
Can I take ashwagandha while pregnant or breastfeeding?
No. Standard Ayurvedic and modern advice is to avoid ashwagandha in pregnancy. Some animal studies have reported early-pregnancy effects, and human pregnancy safety data is absent. Avoid in lactation as well — there is no human safety data. If you are trying to conceive, talk to your GP before using.
Can ashwagandha affect my thyroid medication?
Ashwagandha has been associated with elevated thyroid hormone markers in case reports and small trials. If you take levothyroxine for hypothyroidism, the addition of ashwagandha may raise free T4 / free T3 and lower TSH, potentially needing a dose review. If you have hyperthyroidism or Graves'' disease, the conservative position is to avoid. Talk to your prescribing pharmacist or endocrinologist. [6]
Is ashwagandha a "natural Xanax"?
No. Xanax (alprazolam) is a Prescription-Only benzodiazepine — a controlled medication with well-defined acute receptor-binding action, dependence liability, and prescribing rules. Ashwagandha is a chronic-use food supplement with modest reported effect sizes on self-reported stress scales after 8–12 weeks. The "natural Xanax" framing is marketing language, not clinical equivalence.
Is the FSA / COT ashwagandha safety review a ban or a recall?
No. The Food Standards Agency referred ashwagandha to the Committee on Toxicity (COT) after a rise in reported incidents and ran a call for evidence in 2024. To its October 2025 meeting, the COT had not been able to set a safe level of intake, partly because ashwagandha preparations vary so widely, and flagged that more data on long-term and possible liver effects are needed. That is an ongoing review, not a ban — ashwagandha remains lawful to sell in Great Britain as a food supplement while it continues, although some other countries (for example Denmark) have restricted it. Consumer guidance is to stop and seek medical advice if symptoms of liver irritation develop, and to tell any prescriber what supplements you take. Suspected adverse reactions can be reported via the MHRA Yellow Card scheme.
⚖️ The official position
What may lawfully be claimed about Ashwagandha (Withania somnifera) in Great Britain. This is a regulatory position, not an evidence grade.
No health claim is authorised for Ashwagandha (Withania somnifera) in Great Britain.
This page describes the evidence and online discussion without making a claim.
UK regulatory landscape
UK regulatory tier: Food supplement
EFSA claim status
EFSA evaluation of ashwagandha claims relating to stress, sleep, cognitive function, and physical performance was paused in 2010 as part of the broader botanicals on-hold list. Pending claims may be referenced descriptively as "on hold" but must not be presented as authorised.
UK regulatory rules evolve. This summary is editorial — businesses should consult regulatory counsel; consumers should consult their pharmacist or GP.
🩺 What the guidance says
What UK and international health bodies say. Guidance leads; Camden’s own evidence review follows below.
NHSNot assessed
NHS — Insomnia
The NHS insomnia guidance centres on sleep-hygiene measures — consistent wake times, a dark and quiet bedroom, limiting caffeine, alcohol and screens before bed — and, where insomnia persists, cognitive behavioural therapy for insomnia (CBT-I) and only short-term pharmacy or prescriber-supervised sleep aids. It notes pharmacy sleeping aids may contain ingredients such as valerian; it does not list ashwagandha among the measures it describes. Information from the NHS website, reviewed 19 March 2024.
NHSNot assessed
NHS — Anxiety, fear and panic
The NHS self-help guidance for anxiety, fear and panic centres on talking therapies (including NHS cognitive behavioural therapy, which can be self-referred), breathing and relaxation techniques, physical activity, and sleep and lifestyle measures. It does not list ashwagandha or any food supplement among the steps it describes for managing anxiety. Information from the NHS website, reviewed 17 January 2023.
NICENot assessed
NICE CG113 — Generalised anxiety disorder and panic disorder in adults: management
NICE guideline CG113 sets out the stepped-care management of generalised anxiety disorder and panic disorder in adults, from guided self-help and psychological therapies through to medicines such as SSRIs under clinical oversight. It does not include ashwagandha or other botanical supplements among its recommended interventions. Reproduced under the NICE UK Open Content Licence; this summary does not imply NICE endorsement.
SOCIETY-OTHERInsufficient evidence
Royal College of Psychiatrists — Complementary and alternative medicines: herbal remedies
The Royal College of Psychiatrists' resource on complementary and alternative medicines notes that, for most herbal products used for stress, anxiety or sleep, there is not much good-quality evidence that they work, and advises anyone considering them to speak to their GP or psychiatrist first — particularly if they take other medicines. Own-words summary; copyright remains with the Royal College of Psychiatrists.
GOVUKNot assessed
Food Standards Agency — Ashwagandha safety review (call for evidence; COT assessment in progress)
The Food Standards Agency is reviewing the safety of ashwagandha in food and supplements and has referred the evidence to the Committee on Toxicity (COT). After a rise in reported incidents, the FSA ran a call for evidence in 2024; possible concerns include liver effects, thyroid effects and low blood sugar. To its October 2025 meeting the COT had not been able to establish a safe level of consumption, citing the wide variability between preparations, and more work is ongoing. Ashwagandha remains lawful to sell as a food supplement in Great Britain while the review continues. Contains public sector information licensed under the Open Government Licence v3.0.
GB-NHCNot assessed
Great Britain Nutrition and Health Claims (NHC) Register
Great Britain's statutory register lists every nutrition or health claim a business may lawfully use in commercial communications. No authorised health claim is recorded for ashwagandha or Withania somnifera, so no stress, sleep, mood, hormonal, cognitive or performance benefit may be claimed for it on a UK commercial surface. Contains public sector information licensed under the Open Government Licence v3.0.
EFSANot assessed
EFSA — General function health claims under Article 13
EFSA assesses 'general function' (Article 13) health claims for the EU. The claims relating to botanicals — the category that covers ashwagandha — were placed on hold by the European Commission in 2010 pending a decision on how to handle them, and EFSA has issued no scientific opinion authorising a stress, sleep, cognitive or physical-performance claim for ashwagandha. Summarised from the EFSA Journal open-access record.
BNFConditional
BNF — Levothyroxine sodium (interactions and prescribing information)
🔬 Camden’s evidence review
The research Camden reviewed, graded on its strength. This is our own appraisal — it sits beneath the official guidance above, never above it.
Self-reported stress in healthy adults — chronic use
EvidencelimitedUK and EU authority does not recognise a stress benefit for ashwagandha: NICE pathways for anxiety (CG113) do not list it, the Royal College of Psychiatrists notes there is not much good evidence for herbal products used for stress, and the GB health-claims register carries no authorised claim (see the Guidance section above). Beneath that authoritative position, the research Camden reviewed is early and small: a handful of placebo-controlled trials of KSM-66 root extract (typically 300 mg twice daily, 8–12 weeks; most-cited Chandrasekhar 2012 and Lopresti 2019) reported lower PSS-10 perceived-stress scores and lower morning serum cortisol. Trial sizes are small, durations short, and independent large-scale replication is limited. EFSA stress and cortisol claims for botanicals remain on hold; descriptive trial wording is permissible, claim-style wording is not.
Sleep quality and sleep-onset latency
EvidencelimitedUK guidance leads: the NHS insomnia pathway centres on sleep hygiene and CBT-I, with only short-term pharmacy or prescriber-supervised aids, and does not list ashwagandha (see the Guidance section above). Beneath that, the research Camden reviewed is consistent with an early, modest signal: trials of KSM-66 around 600 mg/day across 8 weeks reported lower self-reported sleep-onset latency and higher sleep-quality index scores. Trials are small and rely on self-report measures, and ashwagandha is not on any UK NICE pathway for insomnia. [1]
Resistance-training performance and body composition
EvidencelimitedThere is no UK-authorised performance claim for ashwagandha — the GB health-claims register carries none, and EFSA's physical-performance botanical claims are on hold (see the Guidance section above). Beneath that, the research Camden reviewed is small and supplier-weighted: trials of KSM-66 600 mg/day in resistance-trained men reported small increases in 1-RM bench press and leg-extension strength and changes in fat-free mass, but trial sizes are small and most were funded by the extract supplier (declared conflict of interest). Independent meta-analytic replication is limited.
Hepatotoxicity and overall safety — UK FSA / COT review (in progress)
EvidencemixedThis is a live UK regulatory question, not a settled one. The Food Standards Agency referred ashwagandha to the Committee on Toxicity (COT) after a rise in reported incidents and ran a 2024 call for evidence; possible concerns include liver effects, thyroid effects and low blood sugar (see the Guidance section above). To its October 2025 meeting the COT had not been able to establish a safe level of intake, citing the wide variability between ashwagandha preparations, and noted that further data on long-term and possible liver effects are needed. The signal context includes post-marketing reports of idiosyncratic liver injury from several jurisdictions. The conservative consumer position is to stop use and seek medical advice if symptoms of liver irritation (right-upper-quadrant pain, nausea, jaundice, dark urine, pale stool) develop. Ashwagandha remains lawful to sell as a food supplement in Great Britain while the review continues.
Anxiety, depression, ADHD
EvidenceinsufficientUK authority is clear here: NHS and NICE pathways for anxiety (CG113), depression (NG222) and ADHD (NG87) do not list ashwagandha, and the Royal College of Psychiatrists advises speaking to a GP or psychiatrist before using herbal products for mental health (see the Guidance section above). Beneath that, the research Camden reviewed is insufficient to support a claim: small, heterogeneous trials in adults with self-reported anxiety symptoms exist, but none establish ashwagandha as a treatment for a diagnosed condition. Self-supplementation in place of formal assessment is not the appropriate pathway. [2,3,4]
Safety
Ashwagandha is generally well-tolerated in healthy adults at standard supplement doses for short durations, but its safety is under active UK review: the FSA / COT are examining possible liver, thyroid and blood-sugar effects and have not set a safe upper level. Discontinue and seek advice if liver-irritation symptoms develop. Pregnancy and lactation: avoid. Thyroid disease: talk to your prescriber.
Talk to your pharmacist or GP first if you:
- You take thyroid medication (levothyroxine, carbimazole, propylthiouracil) — possible additive thyroid effects requiring dose review.
- You take prescribed sedatives, anxiolytics, or hypnotics — possible additive CNS effects.
- You take immunosuppressants (e.g., for autoimmune disease, post-transplant) — ashwagandha may stimulate immune markers and counteract the medication.
- You take antidiabetic medication — possible additive blood-sugar lowering.
- You take anticonvulsants — limited interaction data; disclose use.
- You have liver disease or are taking hepatotoxic medications — UK FSA / CoT 2024 hepatotoxicity signal applies.
- You are pregnant, breastfeeding, or trying to conceive — avoid.
- You have an autoimmune condition (lupus, MS, RA, Hashimoto's, Graves') — ashwagandha is immunostimulatory in some markers.
Common side effects: GI complaints (nausea, loose stools, abdominal discomfort) — particularly at higher doses. Drowsiness can occur. Headache and dry mouth are less commonly reported.
Pregnancy and breastfeeding
Standard Ayurvedic and modern advice is to avoid ashwagandha in pregnancy. Animal studies have reported early-pregnancy effects; human pregnancy safety data is absent.
Limited human safety data; avoid.
Talk to your GP, midwife, or pharmacist before starting any supplement during pregnancy or breastfeeding.
More clinical detail (for clinicians and informed readers)
Contraindications
- Pregnancy — avoid (limited human safety data; animal early-pregnancy effects).
- Lactation — avoid (limited human safety data).
- Active or known hypersensitivity to Solanaceae-family plants (tomato, potato, pepper, aubergine).
- Active liver disease — relative contraindication given the FSA / CoT 2024 hepatotoxicity signal.
Drug interactions
- Thyroid medication (levothyroxine, carbimazole) — possible additive thyroid-axis effects; disclose use to prescriber.
- Sedatives, hypnotics, anxiolytics — possible additive CNS effects.
- Immunosuppressants (e.g., ciclosporin, tacrolimus, methotrexate, biologics) — ashwagandha is immunostimulatory in some markers; possible counteraction.
- Antidiabetic medication — possible additive blood-sugar lowering.
- Anticonvulsants — limited data; disclose use.
- Hepatotoxic medications (paracetamol at high dose, methotrexate, statins, isoniazid) — theoretical additive hepatic concern post-CoT 2024.
This is not an exhaustive list. Always tell your prescriber and pharmacist about every supplement you take.
Common side effects
- GI complaints — nausea, loose stools, abdominal discomfort; substantially reduced by taking with food and starting at a lower dose.
- Drowsiness — particularly at higher doses or in the evening.
Rare side effects
- Headache, dry mouth.
- Allergic reactions — uncommon.
- Idiosyncratic liver injury — UK FSA / CoT 2024 reviewed signals. Stop and seek medical advice if right-upper-quadrant pain, nausea, jaundice, dark urine, or pale stool develops.
How to take it
- Typical supplemental range
- Trials of KSM-66 root extract have most commonly used 600 mg/day (300 mg twice daily) of extract standardised to ≥5% withanolides. Sensoril trials have used 125–250 mg/day at ≥10% withanolides. Generic powder or unstandardised X:1 extract at the same milligram delivers a lower and unstandardised withanolide dose and is not directly comparable.
- Timing
- Daily, with food. Effects emerge over 4–12 weeks; acute / single-dose effects are not reliable. If supplementing for sleep, evening dosing is the trial pattern.
How to spot quality
Look for
- Standardisation declared: withanolide content (≥2.5% minimum, ideally ≥5%) measured by HPLC. The relevant quality marker.
- Branded research-grade preparation (KSM-66, Sensoril, or Shoden) for trial-matched material — KSM-66 is the most-published.
- Plant part declared: root preferred for KSM-66-style use case; root + leaf for Sensoril; leaf-only is not the trial-matched form.
- Solvent declared: water-extracted (KSM-66) is the most-trialled preparation. Hydroalcoholic extracts are also used.
- mg of extract per serving stated; withanolide mg per serving calculable.
- GMP-certified manufacture; heavy-metal screening disclosed (Ayurvedic herbal preparations have historically had heavy-metal contamination concerns).
- Country of cultivation declared (predominantly India).
- Pregnancy contraindication printed on the label.
Red flags
- Generic "ashwagandha root powder" or "Withania somnifera powder" at the same milligram label as standardised extract — unstandardised material.
- X:1 extract ratio (5:1, 10:1, 30:1) marketed as potency without withanolide percentage.
- No withanolide percentage declared on label or supplement-facts panel.
- Marketing as "natural Xanax" / "natural Adderall" / "natural HRT" / "natural testosterone booster".
- Same-day stress-reduction or sleep claims.
- Pregnancy contraindication absent from label.
- No heavy-metal testing disclosure for Ayurvedic-sourced material.
- Leaf-only extract marketed for stress / sleep use cases (the trial literature is on root preparations).
Where Camden lands · meets the bar
Camden has three live SKUs containing ashwagandha. NB-463 Aurifera® Ashwagandha capsules use KSM-66 root extract at 500 mg per capsule (≥5% withanolides — the most-trialled branded preparation). NB-537 Aurifera® Shilajit Adaptogen Complex uses KSM-66 alongside Shilajit at 125 mg KSM-66 per capsule. NB-523 Aurifera® Ashwagandha gummies deliver ashwagandha root extract at 1200 mg per 2-gummy serving.
Commonly combined with
Other ingredients that share a biological pathway, cofactor relationship, or evidence-backed protocol with this one. Mechanisms below cite primary physiology — not folk pairing. Doses are literature ranges, not recommendations. Talk to your pharmacist or GP before changing your stack, especially if you take prescription medication.
Black Pepper (Piper nigrum)
Limited evidencePiperine added to ashwagandha-containing stacks for absorption support; KSM-66 itself does not require piperine for trial-comparable bioavailability.
The KSM-66 root extract has been studied at doses of 300–600 mg/day without piperine; the addition of piperine in multi-active stacks is conventional but not necessary for the ashwagandha component to reach trial-comparable plasma levels.
Evidence: Convention-driven inclusion in adaptogen stacks. Camden NB-537 includes both KSM-66 ashwagandha (125 mg/2-cap) and 250 mg of 95% piperine extract.
Doses studied: 5–20 mg piperine alongside ashwagandha 300–600 mg.
Panax Ginseng (Panax ginseng C.A. Meyer)
Limited evidenceAdaptogen-cluster pairing — different mechanisms (Panax ginsenosides vs Withania withanolides).
Panax ginseng ginsenosides Rb1 / Rg1 modulate HPA axis + cholinergic signalling. Ashwagandha withanolides modulate GABA-A + cortisol. Different active classes; mechanism complementary.
Evidence: Camden ashwagandha NB-463 / NB-523 / NB-537 cluster.
Doses studied: 100-400 mg Panax ginseng standardised extract + 300-600 mg KSM-66 ashwagandha daily.
Rhodiola (Rhodiola rosea)
Limited evidenceTwo adaptogens with overlapping HPA-axis cortisol-modulation framing; conventional in adaptogen stacks.
Both rhodiola (salidroside, rosavins) and ashwagandha (withanolides) have been studied for HPA-axis cortisol modulation. Mechanistic framing partially overlaps; outcome-trial evidence for the combination as such is limited. Camden NB-537 includes both at doses below the individual trial-comparable dose for each.
Evidence: Conventional in adaptogen stacks. Camden NB-537 supplies 125 mg rhodiola + 125 mg KSM-66 ashwagandha per 2-cap serving. Combination outcome trials are sparse.
Doses studied: Rhodiola 200–400 mg + ashwagandha 300–600 mg daily.
Verifera® editorial perspective
Why it matters. Ashwagandha is marketed widely for stress, sleep and "cortisol", yet UK and EU regulators authorise no such claim, and the FSA is actively reviewing its safety. Knowing where the authoritative guidance stands — and that the standardisation on the label drives whether a product even resembles what the trials used — makes it easier to read a label critically before spending.
Where Camden lands. Camden retails ashwagandha as a traditional Ayurvedic food supplement only. We make no stress, sleep, mood, hormonal or performance claim for it, because no authorised GB health claim exists. Where Camden's own SKUs meet the standardisation bar set below we say so plainly; where a product does not (the generic 30:1 gummy), we flag the transparency gap rather than gloss it.
If you want to explore further. For persistent stress, low mood, sleep problems or a thyroid concern, the appropriate UK first step is an NHS assessment — talk to your pharmacist or GP. The quality markers below apply to any ashwagandha brand, not only Camden's.
Sources
Numbered references cited above plus general authoritative reading. Citations in the body link to the matching number here.
How to read these sources:
- Tier 1 (UK authoritative): NHS, NICE, BNF, EFSA, FSA, GB NHC Register, SACN, MHRA.
- Tier 2 (primary literature): peer-reviewed RCTs cited by PMID.
- Tier 3 (mechanistic): in-vitro / animal-model literature — interpret with caveat.
- NHS — Insomnia
- NICE — CG113: Generalised anxiety disorder and panic disorder in adults
- NICE — NG222: Depression in adults: treatment and management
- NICE — NG87: Attention deficit hyperactivity disorder: diagnosis and management
- NICE — NG145: Thyroid disease: assessment and management
- BNF — Levothyroxine sodium
- GB Nutrition and Health Claims Register (gov.uk)
- MHRA Yellow Card Scheme
- NCBI LiverTox — Ashwagandha (Withania somnifera)
How this entry was researched
Authoritative sources consulted:
- NHS — Insomnia (reviewed 2024-03-19)
- NHS — Anxiety, fear and panic (reviewed 2023-01-17)
- NICE CG113 — Generalised anxiety disorder and panic disorder in adults
- Royal College of Psychiatrists — Complementary and alternative medicines
- Food Standards Agency — Ashwagandha call for evidence / COT safety review (in progress)
- GB Nutrition and Health Claims register (gov.uk)
- EFSA — Article 13 general-function health claims (botanicals on hold)
- BNF — Levothyroxine sodium (interactions, link-only)
- NCBI LiverTox — Ashwagandha (NBK548536, US tertiary, corroborative only)
PubMed search terms:
Withania somnifera stress cortisol randomised controlled trialKSM-66 ashwagandha sleep insomnia trialashwagandha hepatotoxicity liver injury caseashwagandha thyroid levothyroxine interaction
Literature search date: 2026-06-12
Sources listed are those consulted by the Verifera® editorial team. Readers should verify against current authoritative sources.