NOW Foods L-Theanine 200mg vs NOW Foods Glycine Pure Powder

Q: Which is better, NOW Foods L-Theanine 200mg or NOW Foods Glycine Pure Powder?

NOW Foods L-Theanine 200mg scores 85.0/100 while NOW Foods Glycine Pure Powder scores 78.0/100 in our analysis. NOW Foods L-Theanine 200mg is the higher-rated product overall.

Q: Is NOW Foods L-Theanine 200mg worth the price compared to NOW Foods Glycine Pure Powder?

NOW Foods L-Theanine 200mg scores 88.0/100 for value, while NOW Foods Glycine Pure Powder scores 88.0/100. Check our price comparison above for the latest UK prices.

Side-by-side comparison of scores, ingredients, prices and real customer feedback for NOW Foods L-Theanine 200mg and NOW Foods Glycine Pure Powder.

Last verified: 07 Apr 2026 · Based on 97 reviews

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85.0

Quick Answer

NOW Foods L-Theanine 200mg scores 85.0/100 vs NOW Foods Glycine Pure Powder at 78.0/100. NOW Foods L-Theanine 200mg wins on effectiveness, ingredient quality, certifications. NOW Foods Glycine Pure Powder is stronger on side effects.

Which is better: NOW Foods L-Theanine 200mg or NOW Foods Glycine Pure Powder?

NOW Foods L-Theanine 200mg wins with an 85/100 score versus Glycine's 78/100, backed by more consistent real-world effectiveness (82 vs 68). Its caffeine-stacking benefits and clear per-dose clarity make it the more reliable daily choice. Choose Glycine if you want a melatonin-free sleep aid in bulk powder form at exceptional cost per dose.

— AIScored Editorial Team

How Do the Scores Compare?

NOW Foods L-Theanine 200mg

NOW Foods Glycine Pure Powder

	NOW Foods L-Theanine 200mg NOW Foods	NOW Foods Glycine Pure Powder NOW Foods
Overall Score	85.0	78.0
Effectiveness	82.0/100 Best	68.0/100
Ingredient Quality	91.0/100 Best	84.0/100
Value for Money	88.0/100 Best	88.0/100 Best
Side Effects	89.0/100	91.0/100 Best
Certifications	90.0/100 Best	77.0/100
Best Price	£21.90 Amazon UK → Cheapest	View →
Price per Serving	£0.18 120 servings	N/A
Form	Capsules	Powder
Dose	200mg L-theanine	1000mg glycine per serving
Third-Party Tested	✓ Yes	✓ Yes
Reviews Analysed	77	20

NOW Foods L-Theanine 200mg

Pros

✓Promotes calm focus without drowsiness — the single most consistent user-reported benefit across dozens of reviews
✓Highly effective as a caffeine stack — users report it eliminates jitters, hand tremors, and anxiety while preserving energy
✓Excellent value: 120 capsules at 200mg per capsule lasts months even with daily use
✓Clean, minimal formula using patented Suntheanine (pure L-isomer) plus 100mg inositol for added calming synergy

Cons

✗Effects are subtle for some users — those expecting dramatic, immediate relaxation may be underwhelmed
✗Rare paradoxical response: at least one reviewer reported worsened insomnia, likely due to mild serotonergic/alertness activity
✗May interact with psychiatric medications (SSRIs, benzodiazepines, MAOIs) — users should consult a doctor
✗Mild blood pressure-lowering effect may be a concern for those already prone to hypotension

Best For

Coffee drinkers wanting to eliminate caffeine jitters while keeping focus Office workers and students managing daily stress and mental fatigue People with mild anxiety seeking a non-sedating, non-prescription option Vegans and those avoiding allergens (gluten, dairy, soy, nuts, shellfish-free) Nootropic beginners looking for a well-researched, low-risk entry point

Amazon UK £21.90

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NOW Foods Glycine Pure Powder

Pros

✓Genuinely pure single ingredient — no fillers, binders, or additives of any kind
✓Outstanding value: 454 g tub provides 151+ full therapeutic (3 g) sleep doses
✓GMP-certified and NPA A-rated manufacturing with third-party testing
✓Mildly sweet natural taste makes it easy to mix into water or a drink

Cons

✗Each serving is only 1 g — the clinically studied sleep dose (3 g) requires three scoops, which is not clearly flagged on the label
✗General NOW Foods quality concerns circulate on Reddit (notably regarding their magnesium glycinate), creating brand-level uncertainty even where product-specific evidence is absent
✗Authenticity questions raised by at least one long-term user who noticed label variation between batches purchased online
✗Powder format is less convenient than capsules for on-the-go use

Best For

People seeking evidence-based sleep quality improvement without melatonin Those wanting to boost dietary glycine for collagen and skin support Budget-conscious buyers who prefer powder over capsules Vegans and individuals with multiple food allergies needing a clean supplement Older adults interested in glycine's role in glutathione production and healthy ageing

Amazon UK View →

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What does the data say about NOW Foods L-Theanine 200mg vs NOW Foods Glycine Pure Powder?

These are two very different amino acid supplements that happen to share a brand. L-Theanine arrives as individual 200mg capsules delivering a single, well-characterised compound found naturally in green tea, while the Glycine product is a loose powder with 1g per scoop. L-Theanine scores 85/100 overall, with ingredient quality at 91/100 and effectiveness at 82/100 — it has a clear, fast-acting mechanism, typically within 30–60 minutes of dosing. Glycine scores 78/100 overall with a noticeably lower effectiveness score of 68/100, partly because the clinically studied sleep dose is 3g, meaning three scoops per serving rather than the one the serving size implies. Both score 88/100 on value, and both carry third-party testing, though L-Theanine comes with a listed price of £21.90 for 120 capsules while Glycine has no listed price.

If you drink coffee and want to reduce jitters without losing the energy lift, L-Theanine is the straightforward pick — the user evidence is unusually consistent on this point. It works equally well for office workers or students managing background stress who want something non-sedating and non-prescription. Glycine suits people focused on sleep quality (particularly those put off by melatonin's grogginess), or anyone wanting to increase dietary glycine for collagen and skin support. Being unflavoured powder, it also works well for people who can't swallow capsules.

On practicalities: L-Theanine has little to flag beyond a rare paradoxical alertness response in sensitive users. Glycine is tasteless and mixes cleanly into water, but the dosing gap is worth understanding before you buy — three level scoops to hit the therapeutic 3g dose means a 454g tub yields roughly 50 meaningful servings, not 150. Both products are GMP-certified with no significant allergen concerns.

NOW Foods L-Theanine 200mg Winner 85.0/100

NOW Foods L-Theanine 200mg using patented Suntheanine is consistently praised by verified iHerb purchasers for delivering a calm, focused mental state without sedation — with the caffeine-pairing use case repeatedly highlighted as a standout benefit.

Effectiveness

NOW Foods L-Thea..

82.0/100

NOW Foods Glycin..

68.0/100

Ingredient Quality

NOW Foods L-Thea..

91.0/100

NOW Foods Glycin..

84.0/100

Value for Money

NOW Foods L-Thea..

88.0/100

NOW Foods Glycin..

88.0/100

Side Effects

NOW Foods L-Thea..

89.0/100

NOW Foods Glycin..

91.0/100

Certifications

NOW Foods L-Thea..

90.0/100

NOW Foods Glycin..

77.0/100

What are the key differences?

NOW Foods L-Theanine 200mg is best for: Coffee drinkers wanting to eliminate caffeine jitters while keeping focus, Office workers and students managing daily stress and mental fatigue

NOW Foods Glycine Pure Powder is best for: People seeking evidence-based sleep quality improvement without melatonin, Those wanting to boost dietary glycine for collagen and skin support

Frequently Asked Questions

Which is better, NOW Foods L-Theanine 200mg or NOW Foods Glycine Pure Powder? ▼

NOW Foods L-Theanine 200mg scores 85.0/100 overall while NOW Foods Glycine Pure Powder scores 78.0/100. NOW Foods L-Theanine 200mg comes out ahead, scoring higher on effectiveness (82.0 vs 68.0). NOW Foods L-Theanine 200mg is best suited for Coffee drinkers wanting to eliminate caffeine jitters while keeping focus and Office workers and students managing daily stress and mental fatigue. NOW Foods Glycine Pure Powder is better for People seeking evidence-based sleep quality improvement without melatonin and Those wanting to boost dietary glycine for collagen and skin support.

Is NOW Foods L-Theanine 200mg worth the price compared to NOW Foods Glycine Pure Powder? ▼

For value, NOW Foods L-Theanine 200mg scores 88.0/100 vs NOW Foods Glycine Pure Powder's 88.0/100. Both offer similar value for money. Note that NOW Foods L-Theanine comes as capsules while NOW Foods Glycine Pu is powder, which may affect your preference.

Which has fewer side effects? ▼

NOW Foods L-Theanine 200mg scores 89.0/100 for side effects (higher means fewer reported issues) while NOW Foods Glycine Pure Powder scores 91.0/100. Reviewers report fewer side effects with NOW Foods Glycine Pure Powder. For certification and testing, NOW Foods L-Theanine scores 90.0/100 vs NOW Foods Glycine Pu's 77.0/100. Always consult a healthcare professional before starting any supplement.

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Disclaimer: AIScored provides data-driven comparisons based on publicly available reviews. This is not medical advice. Affiliate links may earn us a commission at no extra cost to you.

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