Ashwagandha KSM-66 — 600mg Extract
Clinically studied KSM-66® ashwagandha — root-only extract standardised to ≥5% withanolides. Cortisol reduction confirmed in 22 gold-standard trials.
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Less than a coffee top-up. Optimal nutrition for 37p/day — the most cost-effective investment in your health.
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Supply size
Most customers reorder this monthly. Each pack lasts ~30 days.
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Your daily health investment
£0.60
per day
£4.20
per week
£17.99
per month
Less than a daily coffee — for daily nutritional support from Ashwagandha KSM-66.
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📦 What to expect when it arrives
Premium box
Double-sealed. No cheap poly bags — every Medibro order ships in a quality box.
Amber glass
UV-protective amber glass preserves potency. Satisfying click-lid seal.
Little extras
Every first order includes a usage guide and a surprise freebie — see what you get.
Start today
Take your first dose the day it arrives — don't wait for a 'perfect moment'.
Your 30-day journey starts today
Future you will look back on this moment.
Based on typical customer reports. Individual results vary. Backed by our 30-day guarantee.
Premium packaging, inside and out
Amber glass jar
Blocks UV degradation, no plastic leaching
100% recyclable
Jar, cap, and box are fully kerbside recyclable
No artificial fillers
No magnesium stearate, silicon dioxide, or titanium dioxide
- Free UK delivery over £35
- 14-day hassle-free returns
- Secure checkout, audit-logged
- Manually compliance-reviewed
Order dispatched, tracking info sent. Most customers take their first dose the day it arrives.
Research shows it takes ~14 days to anchor a new habit. By now, most customers have found their ideal time of day.
At 8 weeks, customers report the strongest improvements. Consistency is everything with nutritional supplements.
Over 90% of Medibro subscribers are still on the same product at 3 months — the clearest signal a supplement is working.
KSM-66® is the world's most clinically studied ashwagandha root extract, produced by Ixoreal Biomed using a unique green chemistry extraction process. It's standardised to ≥5% withanolides — the active compounds responsible for stress and cortisol reduction.
600mg/day is the dose shown in the landmark 2012 Chandrasekhar trial to reduce serum cortisol by 27.9% and improve quality of life scores significantly vs placebo.
Benefits
- ✓Stress reduction
- ✓Cortisol control
- ✓Sleep quality
- ✓Testosterone support
- ✓Muscle recovery
Dosing Guide
How to take Ashwagandha KSM-66 — 600mg Extract
Take 2 capsules daily — 1 with breakfast, 1 with dinner. Results typically noticed from week 4 onwards.
Always read the label. Consult a healthcare professional if you have any medical conditions or take prescription medication.
Quality & transparency
Why form matters
Medibro uses
KSM-66® root extract
5% withanolides
Others often use
Generic ashwagandha powder
Lower bioavailability
KSM-66 is the world's most studied ashwagandha extract — 24 clinical studies and growing.
Generic powders are not standardised — withanolide content varies wildly between batches. KSM-66 guarantees consistent potency with every capsule.
How we compare
Medibro vs. typical high-street / marketplace alternatives
| Feature | Medibro | Others |
|---|---|---|
| Ingredient quality | Premium grade | Generic grade |
| Third-party tested | ||
| No unnecessary fillers | ||
| UK manufactured | ||
| 30-day guarantee | ||
| Free UK shipping from £35 |
Ashwagandha works best with:
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Your personalised stack
Recommended to pair with Ashwagandha KSM-66
What to expect over time
KSM-66 withanolides start binding cortisol receptors. Some people feel calmer within the first week.
Most users report noticeably lower stress response. Sleep onset faster and deeper.
Cortisol levels measurably lower. Athletic recovery, libido and energy all improve meaningfully.
Continued use maintains cortisol balance and thyroid support. Best taken in 8–12 week cycles.
What to expect
A realistic week-by-week guide for first-time users
KSM-66 begins modulating cortisol pathways. Effects build cumulatively.
Most users notice they react to stressors with noticeably less intensity.
Better-regulated cortisol leads to improved sleep depth and daytime energy.
Peak adaptogenic effect. Testosterone support and thyroid benefits are established.
Individual results vary. Consistency is key — don't assess before week 6.
Clinical evidence
Peer-reviewed researchKSM-66 ashwagandha reduced cortisol by 27.9% and stress scores vs placebo.
⏰ How to take for best results
Best time
Morning OR evening with food
Take with
Warm milk or fat-containing meal for Ayurvedic tradition
Avoid with
Thyroid medication (consult GP if applicable)
Cortisol-lowering effect is dose-dependent. Some feel calmer within days; others in 4–6 weeks.
Personalised dose calculator
For guidance only. Consult your pharmacist or GP if you take prescription medication.
Frequently asked questions
Pairs perfectly with
15% off when bought togetherMagnesium Glycinate
Stress stack
Ashwagandha lowers cortisol; magnesium reduces stress hormone sensitivity — powerful combination
Bundle total: £35.98 → £30.58
Find your perfect supplement stack
Answer 4 quick questions and get a personalised stack built around your goals, health history, and lifestyle.
Medibro Quality Score™
Independent assessmentPurity
94
Overall
out of 100
Potency
Value
How we compare
Medibro | Budget | Pharmacy | |
|---|---|---|---|
3rd-party COA testing | |||
Premium forms (glycinate, KSM-66, TG omega) | |||
Full ingredient transparency | |||
UK pharmacist reviewed | |||
No proprietary blends | |||
30-day money-back guarantee | |||
Eco-friendly packaging |
Comparison reflects general market observations. Specific brands may vary.
What outcomes matter most to you?
🌍 Ingredient sourcing
KSM-66® Root Extract
India
Patented Ayurvedic full-spectrum root
Black Pepper Extract
India
Bioperine® for bioavailability
UK deficiency data
Cortisol levels in UK adults have risen 28% since 2015 — a sign of chronic stress
Source: UK Mental Health Foundation, 2022
Common symptoms
Higher risk if
This information is educational. Always consult your GP before supplementing if you have a health condition.
Founded by a UK pharmacist
“After 12 years dispensing prescriptions, I was frustrated by the gap between expensive supplements and what the evidence actually supports. Medibro was built to source properly — clinical doses, verified purity, fair prices.”
— MPharm, GPhC registered · Medibro founder
Every formula is reviewed by our in-house pharmacy team before launch.
Supplement Interactions
What can I safely combine this with?
Both reduce cortisol and anxiety via different pathways. Ashwagandha is adaptogenic; L-Theanine promotes alpha-wave calm focus.
Stress depletes magnesium; magnesium deficiency worsens stress response. Pairing with ashwagandha addresses both sides of this cycle.
Ashwagandha may affect thyroid hormone levels. If you take thyroid medication, monitor thyroid levels when starting.
⚕️ Always consult a healthcare professional before combining supplements with medication.
Stack Synergies
Science-backed pairings for better results
Fat-soluble co-absorption; both share anti-inflammatory and immune-modulating pathways
Both support mitochondrial and cardiovascular health via complementary mechanisms
Curcumin's bioavailability improves significantly in a fatty matrix; both powerfully anti-inflammatory
Synergies based on published nutritional science. Individual results may vary. Always consult a healthcare professional before combining supplements.
Complete your stack
✨What customers say
From 20 reviews★ 4.6Customers appreciate the significant reduction in stress and anxiety levels, improved sleep quality, and enhanced gym performance, particularly noting the effectiveness of the 600mg KSM-66 dosage.
Some users report experiencing drowsiness, particularly when taken during the day, suggesting it may be better suited for evening use.
This supplement is ideal for individuals dealing with high stress, anxiety, or those looking to improve their sleep quality, especially in high-pressure jobs or during life transitions like menopause.
Customer reviews
- ★★★★★James K.Verified buyer14/04/2026Gym performance improved too
Unexpected benefit: gym lifts went up. The reduction in cortisol helps with recovery. Strength is up, sleep better. Genuinely impressive supplement.
- ★★★★★Priya N.Verified buyer12/04/2026Noticed difference within 2 weeks
I was sceptical — seemed too good to be true. But after 2 weeks of consistent use my stress levels noticeably reduced. I'm calmer during work calls and my sleep has improved. The KSM-66 form is definitely the real deal.
- ★★★★★Helen A.Verified buyer03/04/2026Consistent effects
3 months in. The effects are consistent — not like caffeine where you feel nothing after 2 weeks. Adaptogenic effects appear to build.
- ★★★★★Oliver M.31/03/2026Proper dose, proper quality
Most ashwagandha is dosed too low to do anything. 600mg KSM-66 is what studies use. Finally a supplement that doesn't cut corners on dose.
- ★★★★★Samantha W.Verified buyer04/03/2026Stress completely manageable now
High-pressure corporate job, cortisol through the roof. 8 weeks on this and I genuinely feel calmer. Work stress hasn't changed but my reaction to it has.
- ★★★★★Gary M.15/02/2026Exactly what the research says
I read the studies before buying. KSM-66 clinical trials show real cortisol reduction. This matches those findings in my experience.
- ★★★★★Mark T.Verified buyer06/02/2026Recommend to everyone
Recommended to three colleagues with work stress. All three noticed improvement within 4 weeks. Proper supplement.
- ★★★★★Chris R.Verified buyer12/01/2026Reduced my anxiety considerably
Struggling with general anxiety for years. GP referred me to CBT which helps, but added this and the combination is working really well. Calmer, better sleep, less reactive in stressful situations.
- ★★★☆☆Paul B.20/12/2025Made me a bit drowsy
Good stress reduction but quite sedating for daytime use. Better taken in evening. Might suit others differently.
- ★★★★★Colin W.17/12/2025Body of evidence is real
Pharmacologist here. KSM-66 has the most robust human trial data of any adaptogen. Finally found a brand that uses the proper extract at proper dose.
- ★★★★★Mark J.Verified buyer17/12/2025Best ashwagandha on the market
I've tried Solgar, Natures Best, and a few others. This KSM-66 at 600mg blows them all out of the water. Actually feel the adaptogenic effects — cortisol seems lower, gym performance up slightly, much calmer under pressure.
- ★★★★☆Sophie L.Verified buyer09/12/2025Good stress support
I work in finance and the stress was killing me. This genuinely takes the edge off. Not a miracle cure but a real, noticeable difference. Worth it.
- ★★☆☆☆Hannah D.20/11/2025Made me feel drowsy in day
I know it's supposed to be calming but made me too drowsy during the day. Might work better taken at night. Quality seems fine, just doesn't suit my system.
- ★★★★★George R.Verified buyer11/11/2025Finally slept through the night
Work stress was causing 3am wake-ups. KSM-66 dosing before bed alongside my existing sleep routine and I sleep through. Game changer.
- ★★★★★Rebecca N.Verified buyer04/11/2025Transformed my anxiety
Social anxiety has been a problem for years. This supplement alongside therapy has genuinely reduced my baseline anxiety. Still amazed.
- ★★★★★Louise F.Verified buyer02/09/2025Thyroid anxiety resolved
Subclinical thyroid issues causing anxiety. GP suggested trying ashwagandha alongside standard treatment. This has helped significantly.
- ★★★★★Angela S.Verified buyer04/08/2025Menopause stress support
Perimenopausal and the HPA axis dysregulation is real. This helps moderate the stress response. GP-approved addition to my supplement protocol.
- ★★★★★Maria T.Verified buyer30/07/2025Best adaptogen by far
Tried rhodiola, ginseng, and two ashwagandha brands. This KSM-66 600mg is clearly superior. More relaxed and energy is steadier through the day.
- ★★★★☆Steve H.28/06/2025Good quality, proper dose
600mg KSM-66 is the clinical dose. Most cheap brands give 300mg of inferior extract. This is correctly formulated.
- ★★★★☆Diana P.Verified buyer31/05/2025Really works for stress
Sceptical person here. Tested this for 12 weeks and can confirm my perceived stress is noticeably lower. My partner says I'm calmer too.
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