Stress and mood · Stress

Stress that won’t switch off: what helps, and the supplement trials

You are tired but wired, replaying the day at 11 p.m., jaw tight. The most reliable fixes are boring: sleep timing, movement, less caffeine and a real wind-down. Ashwagandha and L-theanine have the best supplement trials; here is what they can and cannot do.

By Kymata Health Editorial Sources cited inline Prices checked Oct 29, 2026

We earn a commission if you buy through some links on this page. You pay the same price. See how we make money.

Quick answer

The quick answer

Sleep, movement, daylight, less caffeine and alcohol, and a wind-down routine have the strongest evidence for stress.
Ashwagandha lowered stress and anxiety scores in trials, though certainty was low; rare liver injury has been reported.
L-theanine modestly lowered acute stress, mostly at higher daily amounts.
"High cortisol" from a random saliva test is not a diagnosis. Persistent stress or anxiety deserves a clinician; therapy works.

We may earn a commission if you buy through these links. That never changes a rank. See how partner links work.

Story

A story you might recognize

Composite story built from common reader accounts; details changed. Not a testimonial.

She is 39, runs a team, and lies awake running through tomorrow. Social feeds told her she had "high cortisol" and sold her a cortisol-balancing blend.

What helped was a fixed bedtime, coffee before noon, a 20-minute walk at lunch and a phone that charges outside the bedroom. She added L-theanine in the evening and later ashwagandha. Six weeks in, she was falling asleep faster. When a bad patch came back, she booked a few sessions with a therapist.

In depth

About "high cortisol"

Cortisol follows a daily rhythm: highest in the morning, lowest at night. Stress can shift it, but one saliva or blood test cannot tell you your rhythm is broken, and true cortisol excess (Cushing’s syndrome) is rare and has specific signs. Products that promise to "lower cortisol" are selling the idea more than the evidence.

The plan

Protect the last hour. Screens off, lights low, a routine your brain learns to expect.
Move daily. A brisk walk counts. Exercise lowers anxiety in trials.
Cut caffeine after noon and limit alcohol. Both disrupt sleep and raise next-day stress.
L-theanine, then ashwagandha. One at a time, judged over 4–8 weeks.
Get support. If stress lasts weeks or affects work and relationships, talk to a clinician or therapist.

The stack

The switch-off stack

Two supplements with trial data and an optional magnesium, alongside the habits that matter more. Evidence grade: A strong · B moderate · C limited · D preliminary.

01Paid links · we earn a commission
L-theanine
Takes the edge off without sedation; pairs well with a wind-down routine.
What the research shows: A 2026 meta-analysis of 31 trials (1,168 people) found L-theanine modestly lowered acute stress (SMD 0.31), mostly in studies at 400 mg a day or more (PMID 42410082). A small trial in generalized anxiety disorder found no benefit over placebo. (PMID 42410082)
- Generally well tolerated. It can add to the effect of blood-pressure medicines and sedatives.
In the studies
- In the 2026 meta-analysis, acute-stress benefits came mostly from studies of 400 mg a day or more; a single 200 mg serving was used for attention.
A record of what researchers gave, in whom; not a dose for you.
Evidencemoderate (Grade B)
Quick pick · Momentous
Brands that pay us are shown first in this list.
Momentous L-Theanine
1 capsule: L-theanine 200 mg; NSF Certified for Sport (label read 2026-10-08)
$39.9960 servings · price checked Oct 29, 2026 on Momentous’ site
One-time
$39.99
Subscription
$29.99
Subscribe 25% off
Shop at Momentous (paid link, opens in new tab)
We may earn a commission if you buy through these links. That never changes a rank. See how partner links work.
Also from our partners
Only brands that pay us are listed here.
- L-TheanineSupersmart
  4 capsules: 400 mg L-theanine from 1,000 mg green tea extract standardised to 40%; the label also lists about 50 mg caffeine per daily dose; 15 servings
  $20checked Oct 11, 2026 on Supersmart’s site
  Shop at Supersmart (paid link, opens in new tab)
Subscribe & save 25%. Pick “Subscribe 25% Off” on the product page; delivery every 1, 2 or 3 months; cancel or reschedule anytime.
- Subscription price shown on each product card.
- Our Momentous links apply the brand’s ambassador discount at checkout, so there is no code to type. Momentous sets any discount it applies; check the cart total before you pay.
- Offer terms from Momentous’ site, checked Oct 8, 2026. Offers can change; the brand's checkout is final.
02Paid links · we earn a commission
Ashwagandha root extract
The best-studied herb for feeling stressed and wound up.
What the research shows: A 2022 meta-analysis (1,002 people) found stress and anxiety scores fell versus placebo, but trials disagreed a lot and certainty was low. A 2025 analysis found cortisol fell by about 1.2 µg/dL while perceived stress did not change significantly. Real but uncertain. (PMID 36017529, PMID 40746175)
- Rare but serious liver injury has been reported; stop and see a clinician if you notice dark urine, yellow skin or eyes, or unusual tiredness.
- May raise thyroid hormone levels; ask first if you have a thyroid condition or take thyroid medicine.
- Not for pregnancy or breastfeeding. Ask first if you take sedatives, immunosuppressants or diabetes or blood-pressure medicines.
In the studies
- Trials gave 120–1,250 mg a day of standardized extract for 6 to about 13 weeks; a dose-response analysis favoured 300–600 mg a day for stress.
A record of what researchers gave, in whom; not a dose for you.
Evidencemoderate (Grade B)
Quick pick · Momentous
Brands that pay us are shown first in this list.
Momentous Ashwagandha, 60 capsules
1 capsule: 300 mg NooGandha ashwagandha extract (standardized to 3.5% withanolides); 60 servings
$24.99price checked Oct 15, 2026 on Momentous’ site
One-time
$24.99
Subscription
$18.74
Shop at Momentous (paid link, opens in new tab)
We may earn a commission if you buy through these links. That never changes a rank. See how partner links work.
Also from our partners
Only brands that pay us are listed here.
- NOW Foods KSM-66 Ashwagandha, 90 Veg CapsHerbsPro
  1 veg capsule: 600 mg organic KSM-66 ashwagandha root extract
  $18.41checked Oct 14, 2026 on HerbsPro’s site
  Shop at HerbsPro (paid link, opens in new tab)
- Botanic Choice Ashwagandha Extract, 90 capsulesBotanic Choice
  1 vege capsule: 450 mg ashwagandha root extract (1.5% withanolides, 6.75 mg); label directions 1 capsule 1 to 3 times daily with a meal
  $24checked Oct 12, 2026 on Botanic Choice’s site
  Shop at Botanic Choice (paid link, opens in new tab)
- Physician’s Choice KSM-66 Ashwagandha (60 capsules)Physician’s Choice
  2 capsules: 1,000 mg per serving as listed by the brand, from organic KSM-66 ashwagandha root extract (standardized to 5% withanolides) with organic black pepper extract; 30 servings
  $29.97checked Oct 20, 2026 on Physician’s Choice’s site
  Shop at Physician’s Choice (paid link, opens in new tab)
03OptionalPaid links · we earn a commission
Magnesium glycinate
Optional. Most useful if your diet is low in magnesium; the evidence for anxiety is weak.
What the research shows: A 2017 systematic review of 18 studies, all in people already prone to anxiety (mild anxiety, PMS, postpartum, high blood pressure), found about half showed some benefit on self-rated anxiety, but the studies were small and of poor quality. (PMID 28445426)
- Stay at or under 350 mg/day of supplemental magnesium unless a clinician says otherwise (US upper limit for supplements).
- Kidney disease: ask first. Separate from thyroid medicine, some antibiotics and bisphosphonates by 2–4 hours.
In the studies
- The 18 studies in the 2017 systematic review gave magnesium alone or with up to 5 other ingredients; amounts varied.
A record of what researchers gave, in whom; not a dose for you.
Evidencelimited (Grade C)
Quick pick · Momentous
Brands that pay us are shown first in this list.
Momentous Magnesium Bisglycinate
2 capsules: 200 mg elemental magnesium (as bisglycinate)
$16.9930 servings · price checked Oct 29, 2026 on Momentous’ site
One-time
$16.99
Subscription
$12.74
Subscribe 25% off
Shop at Momentous (paid link, opens in new tab)
We may earn a commission if you buy through these links. That never changes a rank. See how partner links work.
Also from our partners
Only brands that pay us are listed here.
- Supersmart Magnesium Bisglycinate (TRAACS)Supersmart
  4 capsules: 3,000 mg Albion TRAACS magnesium bisglycinate = 300 mg elemental magnesium, no magnesium oxide
  $39checked Oct 29, 2026 on Supersmart’s site
  Shop at Supersmart (paid link, opens in new tab)
- NOW Foods Magnesium Glycinate, 90 TabsHerbsPro
  2 tablets: 200 mg elemental magnesium from magnesium bisglycinate (Albion)
  $11.24checked Oct 14, 2026 on HerbsPro’s site
  Shop at HerbsPro (paid link, opens in new tab)
- Dr. Tobias Magnesium Bisglycinate (120 capsules)Dr. Tobias
  1 vegetable capsule: 200 mg magnesium as magnesium bisglycinate chelate buffered with magnesium oxide (Albion TRAACS)
  $29.99checked Oct 14, 2026 on Dr. Tobias’ site
  Shop at Dr. Tobias (paid link, opens in new tab)

Listed picks above total $81.97 at one-time prices on the brands' own sites; most hold about a month of servings at the label's serving size.

Left out

What we left out, and why

"Cortisol cocktails" and adrenal blends: Orange juice, coconut water and salt do not lower cortisol, and "adrenal fatigue" is not a recognized diagnosis.
Kava: Some trials suggest it calms anxiety, but it has been linked to severe liver injury and is restricted in several countries.

Safety

Safety and interactions

If you have thoughts of harming yourself or feel unable to keep yourself safe, call or text 988 (the Suicide and Crisis Lifeline in the US) or your local emergency number now.
Never stop or change an antidepressant or other prescribed medicine without your prescriber; stopping suddenly can cause withdrawal effects and relapse.
Low mood, anxiety or exhaustion that lasts more than two weeks, or gets in the way of work, relationships or sleep, deserves a clinician. Talking therapies and medicines have strong evidence.
Not medical advice. Check with your clinician or pharmacist before starting supplements if you take prescription medicines, are pregnant or breastfeeding, or have liver, kidney or thyroid disease.
Supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease.

Questions

Frequently asked questions

Does ashwagandha lower stress?

In a 2022 meta-analysis, ashwagandha lowered stress and anxiety scores versus placebo, but trials disagreed a lot and certainty was low. Most trials used a root extract.

Is ashwagandha safe?

It is usually well tolerated in trials, but rare serious liver injury has been reported, and it may affect thyroid hormone. It is not for pregnancy or breastfeeding.

What amounts did the L-theanine stress trials use?

In a 2026 meta-analysis of 31 trials, L-theanine modestly lowered acute stress, mostly in studies at 400 mg a day or more (PMID 42410082).

Sources

Studies were checked on PubMed on Oct 31, 2026. Product prices come from each brand's own site, read on Oct 29, 2026; each product shows the date its price was read.

Keep reading: Supplement stacks

Supplement stacks: every page All stacks Browse all topics

The sleep stack Also in: Supplements and vitamins

Stress that won’t switch off: what helps, and the supplement trials

L-theanine

Momentous L-Theanine

Ashwagandha root extract

Momentous Ashwagandha, 60 capsules

Magnesium glycinate

Momentous Magnesium Bisglycinate