Head to head · Sleep & Stress
Nutricost KSM-66 Ashwagandha Root Extract 600 mg vs Sports Research L-Theanine 200 mg with Suntheanine
Nutricost and Sports Research finish level in our scoring (8.1 vs 8.0), so the right pick depends on what you value most — Nutricost is stronger on value, Sports Research on experience and transparency.
Updated September 2026 from our full reviews · How we score
A full 600 mg daily dose of organic KSM-66 ashwagandha in one capsule for about $0.25-$0.28 a day. Strong value; not for pregnancy or thyroid conditions.
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A simple, well-dosed 200 mg Suntheanine softgel for calm focus and wind-down, at about $0.33 a day. Contains gelatin and coconut.
We may earn a commission when you buy through these links — it never affects our scores. How we make money
We may earn a commission when you buy through these links — it never affects our scores. How we make money
The short answer
Choose Nutricost if…
- Budget-conscious buyers
- Stress-related sleep trouble
- People who want a single daily capsule
- You care most about value
- You want the lower cost per serving ($0.28)
Choose Sports Research if…
- Stress and racing thoughts at bedtime
- Calm focus without drowsiness
- People who want a single-ingredient formula
- You care most about experience, transparency
Side by side
| KSM-66 Ashwagandha Root Extract 600 mg | L-Theanine 200 mg with Suntheanine | |
|---|---|---|
| Our score | 8.1 / 10 | 8.0 / 10 |
| Efficacy (30%) | 7.8 | 7.8 |
| Quality & Purity (25%) | 7.4 | 7.5 |
| Value (20%) | 9.0 | 8.3 |
| Experience (15%) | 8.2 | 8.5 |
| Transparency (10%) | 8.5 | 8.8 |
| Form | Capsule | Softgel |
| Serving | 1 capsule60 servings per container | 1 softgel60 servings per container |
| Price per serving | $0.28 | $0.33 |
| Testing & certifications | cGMP facilityThird-party tested | Third-party testedcGMP facility |
| Dietary | Vegetarian, Gluten-free, Non-GMO | Gluten-free, Non-GMO |
| Key ingredients |
|
|
| Flavors | — | — |
| Creator video reviews | 3 | 3 |
Pros and cons
KSM-66 Ashwagandha Root Extract 600 mg
- 600 mg KSM-66 per capsule, the dose range where a meta-analysis found stronger sleep effects
- About $0.25-$0.28 per daily serving
- Label discloses standardization: at least 5% withanolides and under 0.1% withaferin A
- Organic KSM-66 in a vegetarian capsule; non-GMO and gluten-free
- Benefits build over weeks, and some buyers report no effect
- Headaches reported by some buyers; not for pregnancy, with rare liver-injury reports and possible thyroid effects
- No NSF, Informed Choice or similar product certification despite third-party testing claims
L-Theanine 200 mg with Suntheanine
- 200 mg Suntheanine per softgel, matching the dose used in a 2019 randomized trial
- Single active ingredient with a short, fully disclosed label
- Third-party tested, cGMP-compliant, gluten-free and IGEN Non-GMO tested
- About $0.33 per serving at list price
- Gelatin softgel is not suitable for vegetarians; label lists coconut as a tree-nut allergen
- Some buyers report stomach upset, and the softgels are on the larger side
- No NSF, USP or similar product certification
- Effects are subtle; 200 mg is at the low end of the dose range linked to better sleep
Our verdicts
KSM-66 Ashwagandha Root Extract 600 mg
This is a no-frills, correctly dosed KSM-66 product at one of the lowest prices in the category, which makes it our value pick for ashwagandha. The evidence for stress and sleep is encouraging but modest, and the safety caveats around thyroid, liver and pregnancy are real, so it is best treated as an eight-week trial with a clinician's okay rather than a permanent staple.
Full review
L-Theanine 200 mg with Suntheanine
This is an easy recommendation for anyone who wants to try L-theanine: a studied dose of a branded ingredient, a transparent label and consistently strong buyer feedback. Expect subtle calm rather than a knockout effect, and choose a capsule version if you avoid gelatin or coconut.
Full review
What creators say
Questions people ask
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